Tag Archives: springboot error

[Solved] Springboot Reflection calls ServiceImpl Error: java.lang.NullPointerException, mapper is null

Springboot uses reflection to call serviceimpl and reports an error: java.lang.nullpointerexception

Because the mapper of ServiceImpl is null, the following is the original implementation code:

           // package name and class name
           Class classzz = Class.forName("com.XXX.XXX.service.impl.SenDataServiceImpl");

           // Get the constructor object
           Constructor constructor = null;
           try {
               constructor = classzz.getConstructor();
           } catch (NoSuchMethodException e) {
               e.printStackTrace();
           }
           // Create an object using the constructor object
           Object o = constructor.newInstance();
           // Pass the method to be executed Pass the parameter type, if not, you can leave it out
           Method method = classzz.getMethod("method name", long.class,String.class,String.class );
// invoke method, and pass parameters, if there are no parameters, you can leave them out
           Object obj =method.invoke(o,  5,
                  "param1",
                   "param2");

In the post query mode, you need to ContextLoader.getCurrentWebApplicationContext() firstly, but you haven’t gone to invoke, so the ContextLoader.getCurrentWebApplicationContext() is null.

The final solution is as follows:

1. Create a new class SpringBootBeanUtil

package com.smart.hyd.common.utils.reflect;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * SpringBoot Common class to get the bean tool class in the Spring container
 */
@Component
public class SpringBootBeanUtil implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        if (SpringBootBeanUtil.applicationContext == null) {
            SpringBootBeanUtil.applicationContext = applicationContext;
        }
        System.out.println("========ApplicationContext========");
//        System.out.println("========In the general class you can get the applicationContext object by calling SpringBootBeanUtil.getApplicationContext()========");
        System.out.println("========applicationContext="+ SpringBootBeanUtil.applicationContext +"========");
    }

    /**
     * get applicationContext
     * @return
     */
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    /**
     * Get Bean by name.
     * @param name
     * @return
     */
    public static Object getBean(String name) {
        return getApplicationContext().getBean(name);
    }

    /**
     * Get Bean by class.
     * @param clazz
     * @return
     */
    public static <T> T getBean(Class<T> clazz) {
        return getApplicationContext().getBean(clazz);
    }

    /**
     * Return the specified bean by name, and Clazz
     * @param name
     * @param clazz
     * @return
     */
    public static <T> T getBean(String name, Class<T> clazz) {
        return getApplicationContext().getBean(name, clazz);
    }

}

2. Call SpringBootBeanUtil.getApplicationContext(). When invoking, the first parameter is applicationContext.getBean(ServiceImplType). Refer to the following code for specific implementation.

try {
               //Retrieve the created object from the ApplicationContext
               // Do not create the serviceimpi object directly by reflection, because the object created by reflection cannot instantiate the dao interface
               ApplicationContext applicationContext = SpringBootBeanUtil.getApplicationContext();
               //reflection creates the serviceimpi entity object, and the entity class
               Class<? > ServiceImplType = Class.forName("com.XXX.XXX.service.impl.SenDataServiceImpl");
              // Class<? > entityType = Class.forName("com.XXX.XXX.service.impl.SenDataServiceImpl");
               //reflection set method parameters.
               Method method = ServiceImplType.getDeclaredMethod("methodName",long.class,String.class,String.class );
               // get the instantiated bean in the ApplicationContext according to class
               method.invoke(applicationContext.getBean(ServiceImplType), 5,
                           "param1",
                           "param2");

           } catch (ClassNotFoundException | IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
               e.printStackTrace();
               LOGGER.error("\n onMessage Receive Processing Message Failed - {}", "methodName");
           }

This solves the problem that the reflection calls ServiceImpland the mapper reports an error when it is null.

[Solved] Springboot error: Could Not Found xxmapper

springboot error: could not found xxmapper

Error Messages:

Unsatisfied dependency expressed through field ‘baseMapper’; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type ‘com.xxxx.server.mapper.AdminMapper’ available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

 

 

Solution: Add mapper package scan to springboot startup class

@MapperScan("com.xxxx.server.mapper")

[Solved] Springboot Error: Error creating bean with name ‘xxxController‘

Problem description

Today, we are integrating mybatis with springboot, and an error is reported at runtime:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userController': Unsatisfied dependency expressed through field 'userService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userMapper' defined in file [E:\IDEA Project\demo\target\classes\com\example\demo\mapper\UserMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/MybatisPlusAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:659) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:639) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1431) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:619) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.16.jar:5.3.16]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.16.jar:5.3.16]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.4.jar:2.6.4]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) [spring-boot-2.6.4.jar:2.6.4]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) [spring-boot-2.6.4.jar:2.6.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-2.6.4.jar:2.6.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) [spring-boot-2.6.4.jar:2.6.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) [spring-boot-2.6.4.jar:2.6.4]
	at com.example.demo.DemoApplication.main(DemoApplication.java:18) [classes/:na]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userMapper' defined in file [E:\IDEA Project\demo\target\classes\com\example\demo\mapper\UserMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/MybatisPlusAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:659) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:639) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1431) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:619) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1389) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1309) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:656) ~[spring-beans-5.3.16.jar:5.3.16]
	... 20 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userMapper' defined in file [E:\IDEA Project\demo\target\classes\com\example\demo\mapper\UserMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/MybatisPlusAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1534) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1417) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:619) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1389) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1309) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:656) ~[spring-beans-5.3.16.jar:5.3.16]
	... 34 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/MybatisPlusAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:638) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1389) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1309) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1519) ~[spring-beans-5.3.16.jar:5.3.16]
	... 45 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-5.3.16.jar:5.3.16]
	... 58 common frames omitted
Caused by: org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean.buildSqlSessionFactory(MybatisSqlSessionFactoryBean.java:595) ~[mybatis-plus-extension-3.4.0.jar:3.4.0]
	at com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean.afterPropertiesSet(MybatisSqlSessionFactoryBean.java:431) ~[mybatis-plus-extension-3.4.0.jar:3.4.0]
	at com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean.getObject(MybatisSqlSessionFactoryBean.java:628) ~[mybatis-plus-extension-3.4.0.jar:3.4.0]
	at com.baomidou.mybatisplus.autoconfigure.MybatisPlusAutoConfiguration.sqlSessionFactory(MybatisPlusAutoConfiguration.java:214) ~[mybatis-plus-boot-starter-3.3.1.jar:3.3.1]
	at com.baomidou.mybatisplus.autoconfigure.MybatisPlusAutoConfiguration$$EnhancerBySpringCGLIB$$1a37b21a.CGLIB$sqlSessionFactory$2(<generated>) ~[mybatis-plus-boot-starter-3.3.1.jar:3.3.1]
	at com.baomidou.mybatisplus.autoconfigure.MybatisPlusAutoConfiguration$$EnhancerBySpringCGLIB$$1a37b21a$$FastClassBySpringCGLIB$$a0eb9858.invoke(<generated>) ~[mybatis-plus-boot-starter-3.3.1.jar:3.3.1]
	at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.3.16.jar:5.3.16]
	at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331) ~[spring-context-5.3.16.jar:5.3.16]
	at com.baomidou.mybatisplus.autoconfigure.MybatisPlusAutoConfiguration$$EnhancerBySpringCGLIB$$1a37b21a.sqlSessionFactory(<generated>) ~[mybatis-plus-boot-starter-3.3.1.jar:3.3.1]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_322]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_322]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_322]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_322]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.3.16.jar:5.3.16]
	... 59 common frames omitted
Caused by: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:123) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.parse(XMLMapperBuilder.java:95) ~[mybatis-3.5.5.jar:3.5.5]
	at com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean.buildSqlSessionFactory(MybatisSqlSessionFactoryBean.java:593) ~[mybatis-plus-extension-3.4.0.jar:3.4.0]
	... 72 common frames omitted
Caused by: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.apache.ibatis.builder.BaseBuilder.resolveClass(BaseBuilder.java:118) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.xml.XMLStatementBuilder.parseStatementNode(XMLStatementBuilder.java:76) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildStatementFromContext(XMLMapperBuilder.java:138) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildStatementFromContext(XMLMapperBuilder.java:131) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:121) ~[mybatis-3.5.5.jar:3.5.5]
	... 74 common frames omitted
Caused by: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.apache.ibatis.type.TypeAliasRegistry.resolveAlias(TypeAliasRegistry.java:120) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.BaseBuilder.resolveAlias(BaseBuilder.java:149) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.BaseBuilder.resolveClass(BaseBuilder.java:116) ~[mybatis-3.5.5.jar:3.5.5]
	... 78 common frames omitted
Caused by: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:200) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:89) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.io.Resources.classForName(Resources.java:261) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.type.TypeAliasRegistry.resolveAlias(TypeAliasRegistry.java:116) ~[mybatis-3.5.5.jar:3.5.5]
	... 80 common frames omitted

Cause analysis:

When I first saw this error report, I guessed that the bean was not successfully created. I also searched various answers on the Internet. Some said that @ service might not be added to the service layer. I looked at it for no reason, so I began to read the error information

Look directly at the error reported in the first line, because the first line is likely to be the main reason for the error:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userController': Unsatisfied dependency expressed through field 'userService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userMapper' defined in file [E:\IDEA Project\demo\target\classes\com\example\demo\mapper\UserMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/MybatisPlusAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version

I’ll take this long paragraph wrong and look at it in pieces
at first, I thought it was the problem of userController, then carefully check whether it was not, and then look back:

nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userServiceImpl'

I went to see userServiceImpl again and didn’t find any problems, so I was wondering if I understood the error in this paragraph, so I searched the meaning of nest. It turned out that there was nesting besides nesting! That is to say, the error reporting in this paragraph is actually an exception nested with another exception ! In other words, it is the innermost error that causes the error of each layer above, thus throwing an exception! So I went straight to the back part:

nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version

Found to be VersionMapper.xml has a problem because of Error resolving class, That is to say, there is a problem with one class. Look at the last: Cannot find class: com.libv.entity.Version.
I went to see XML again:

<mapper namespace="com.libv.mapper.VersionMapper">
    <insert id="release" parameterType="com.libv.entity.Version">
        insert into version(id,version,download_url,release_time)
        values (#{id},#{version},#{downloadUrl},NOW())
    </insert>
</mapper>

Now I understand, because I don’t have com.libv.entity this bag! That is, the wrong path of my Version class leads to errors in XML, resulting in layer-by-layer exceptions.

Solution:

Change the directory path of the corresponding class of parameterType in XML

<mapper namespace="com.example.demo.mapper.VersionMapper">
    <insert id="release" parameterType="com.example.demo.Entity.Version">
        insert into version(id,version,download_url,release_time)
        values (#{id},#{version},#{downloadUrl},NOW())
    </insert>
</mapper>

Run again, success!

[Solved] Springboot Error: Error creating bean with name ‘dataSource‘ defined in class path resource

Springboot reports error creating bean with name ‘datasource’ defined in class path resource, factory method ‘datasource’ three exception; nested exception is org.springframework.boot.autoconfigure.jdbc.Datasourceproperties $datasourcebeancreationexception: failed to determine a suitabledriver class solution

Problem background solution experience Lyric: cut me apart from two spirits

Problem background:

An error is reported when connecting to MySQL:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Failed to determine a suitable driver class
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:414)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:302)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Failed to determine a suitable driver class
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653)
	... 87 more
Caused by: org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Failed to determine a suitable driver class

Solution:

1. It can be seen from the error report that the configuration of datasource database cannot be found. After inspection, it was forgotten in application The YML configuration file configures the database information

spring:
  datasource:
      #url: jdbc:mysql://[ip]:[port]/[name]?useSSL=false&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&allowPublicKeyRetrieval=true&serverTimezone=Asia/Shanghai
    url: jdbc:mysql://localhost:3306/mysqlTest?serverTimezone=UTC&characterEncoding=UTF-8
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
  sql:
    init:
      encoding: utf-8

[Solved] Springboot Error: swagger-UI/index.html Access Error 404

Springboot solves swagger UI/index HTML Access Error 404

Recently, I was working on a project to adopt swagger 3.0. After the project is started, access the swagger path: http://localhost:8880/vdmpess -web/swagger-ui/index. HTML reports 404 because webmvcconfig inherits webmvcconfigurationsupport. After inheriting this class, the relevant contents configured in the configuration file will become invalid and the static resource needs to be re specified
the swagger static resource needs to be re specified.

Swagger address in project

Solution:

Adds the address of the specified static resource

@Configuration
public class WebMvcConfig extends WebMvcConfigurationSupport {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.
                addResourceHandler("/swagger-ui/**")
                .addResourceLocations("classpath:/META-INF/resources/webjars/springfox-swagger-ui/")
                .resourceChain(false);
    }
}

[Solved] SpringBoot Error: org.springframework.http.converter.HttpMessageNotReadableException

SpringBoot Error: org.springframework.http.converter.HttpMessageNotReadableException

 

org.springframework.http.converter.HttpMessageNotReadableException:
Required request body is missing: * * * * *
at.org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.readWithMessageConverters(RequestResponseBodyMethodProcessor.java:161)

：

After careful investigation, I found that there are no errors in my other codes. Finally, the parameter submission method is wrong, because the @requestbody annotation is mainly used to accept JSON data in post and put methods, so @postmapping should be used here. It’s a perfect solution. I’m really getting farther and farther on the road of rookie

[Solved] Springboot Error: org.apache.catalina.core.ContainerBase : A child container failed during start

Review springboot idea errors:

2021-09-08 21:12:43.851 ERROR 3704 --- [  restartedMain] org.apache.catalina.core.ContainerBase   : A child container failed during start

java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: A child container failed during start
	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_74]
	at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_74]
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) [tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) [tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) [tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) [tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:450) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:199) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) [spring-context-5.3.9.jar:5.3.9]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) [spring-boot-2.5.4.jar:2.5.4]
	at com.sc.myapp.Application.main(Application.java:12) [classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_74]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_74]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_74]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_74]
	at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.0.4.RELEASE.jar:2.0.4.RELEASE]
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:938) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_74]
	at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) ~[na:1.8.0_74]
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	... 26 common frames omitted
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_74]
	at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_74]
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	... 34 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
	at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) [tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) [tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_74]
	at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) ~[na:1.8.0_74]
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	... 34 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/apache/tomcat/util/descriptor/tld/TldParser
	at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) ~[tomcat-embed-jasper-9.0.36.jar:9.0.36]
	at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:100) ~[tomcat-embed-jasper-9.0.36.jar:9.0.36]
	at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:81) ~[tomcat-embed-jasper-9.0.36.jar:9.0.36]
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5219) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.52.jar:9.0.52]
	... 40 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_74]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_74]
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_74]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_74]
	... 45 common frames omitted

2021-09-08 21:12:43.851  INFO 3704 --- [  restartedMain] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2021-09-08 21:12:43.855  WARN 3704 --- [  restartedMain] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
2021-09-08 21:12:43.860  INFO 3704 --- [  restartedMain] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-09-08 21:12:43.873 ERROR 3704 --- [  restartedMain] o.s.boot.SpringApplication               : Application run failed

org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:163) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-5.3.9.jar:5.3.9]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) [spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) [spring-boot-2.5.4.jar:2.5.4]
	at com.sc.myapp.Application.main(Application.java:12) [classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_74]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_74]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_74]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_74]
	at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.0.4.RELEASE.jar:2.0.4.RELEASE]
Caused by: org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:142) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:450) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:199) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) ~[spring-boot-2.5.4.jar:2.5.4]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) ~[spring-boot-2.5.4.jar:2.5.4]
	... 13 common frames omitted
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:938) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) ~[spring-boot-2.5.4.jar:2.5.4]
	... 18 common frames omitted
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: A child container failed during start
	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_74]
	at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_74]
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	... 26 common frames omitted
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:938) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_74]
	at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) ~[na:1.8.0_74]
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	... 26 common frames omitted
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_74]
	at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_74]
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	... 34 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
	at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_74]
	at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) ~[na:1.8.0_74]
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	... 34 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/apache/tomcat/util/descriptor/tld/TldParser
	at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) ~[tomcat-embed-jasper-9.0.36.jar:9.0.36]
	at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:100) ~[tomcat-embed-jasper-9.0.36.jar:9.0.36]
	at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:81) ~[tomcat-embed-jasper-9.0.36.jar:9.0.36]
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5219) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.52.jar:9.0.52]
	... 40 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_74]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_74]
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_74]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_74]
	... 45 common frames omitted

Solution: remove version

I guess it comes with a conflict with the version we imported

But add:

<!-- add the supportion to jsp files -->
		<dependency>
			<groupId>org.apache.tomcat</groupId>
			<artifactId>tomcat-jsp-api</artifactId>
		</dependency>

Otherwise, an error will be reported

[Solved] SpringBoot Error: This application has no explicit mapping for /error,so you are seeing this as a fallback

[problem phenomenon]

In springboot, when there is no error in the request link and the controller configuration, an error will be prompted when accessing a controller link interface:


This application has no explicit mapping for /error,so you are seeing this as a fallback

[reason]

The request cannot find the corresponding bean for processing. If there is no error in the request link and the controller configuration, it may also be the problem of springbootapplication package scanning, as follows:

By default, the @springbootapplication annotation will only the beans of this package and its sub-packages, resulting in the corresponding controller beans not being loaded into the spring container

[solution]

Scheme I:

Move all controller classes to the same level package or sub package of application class, as shown in the figure:

Scheme II:

If you don’t want to change the file location, you can specify the scanned package with the @ springbootapplication annotation:


@SpringBootApplication(scanBasePackages="com.kid")

How to Solve Springboot Error: Failed to convert value of type

Resolved [org.springframework.web.method.annotation.MethodArgumentTypeMismatchException: Failed to convert value of type ‘java.lang.String’ to required type ‘java.lang.Integer’; nested exception is java.lang.NumberFormatException: For input string: “50.5”]

General meaning:
failed to convert the value of type “Java. Lang. string” to the required type “Java. Lang. integer”; Nested exception is java.lang.numberformatexception: for input string: “50.5”]

This kind of error is usually caused by the parameters passed by the front end and the failure of the back end parsing, that is, it is wearing illegal parameters. For example, the upper front end gives me a floating point number, and the back end will fail when the string is parsed into a number!

[Solved] SpringBoot Error: This application has no explicit mapping for /error, so you are seeing this

Springboot project running error:

If you check the directory, the problem lies in the URL in the controller
(1) if: @ requestmapping (“/”)

the URL should be written:

(2) if the URL is like this:

Then @ requestmapping (“/ users”)

is a very simple question… As a result, I took a long walk to look at the XML file and properties for half a day… To record this little problem

[Solved] Error getting bean using springboot: no qualifying bean of type ‘xxx’ available

Recently, I encountered a bug in my work.
the project uses springboot, and uses springcontexthloder, getBean (); No qualifying bean of type ‘xxx’ available

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.tension.web.disabledevaluate.service.DisabledEvaluateService' available

Generally, this error indicates that there is no bean available. Check the code carefully to ensure that this class exists and is injected into spring correctly

Controller:

 public Map loadForm(String round,String instanceId) {
 		//error
        DisabledEvaluateService disabledEvaluateService = SpringContextHolder.getBean(DisabledEvaluateService.class);
 }

Service:

@Service
@Transactional(readOnly = true)
public class DisabledEvaluateService extends CrudService<DisabledEvaluateDao, DisabledEvaluate> {
    public DisabledEvaluate getByBjId(Map map){
        return dao.getByBjIdOrInstanceId(map);
    }

After several hours of exploration, we finally found the information on the Internet because we used the devtools hot deployment plug-in. As a result, when the program starts, we use the classloader rewritten by the devtools hot deployment plug-in instead of the Java default classloader. As a result, some classes may not be loaded correctly, resulting in the inability to obtain beans.

Solution:
this error can be solved without using hot deployment plug-in