Tag Archives: idea

NoClassDefFoundError: io/ebean/bean/ EntityBean [How to Solve]

Error stack frame, as follows:

java.lang.NoClassDefFoundError: io/ebean/bean/EntityBean

	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:348)
	at sun.reflect.generics.factory.CoreReflectionFactory.makeNamedType(CoreReflectionFactory.java:114)
	at sun.reflect.generics.visitor.Reifier.visitClassTypeSignature(Reifier.java:125)
	at sun.reflect.generics.tree.ClassTypeSignature.accept(ClassTypeSignature.java:49)
	at sun.reflect.generics.visitor.Reifier.reifyTypeArguments(Reifier.java:68)
	at sun.reflect.generics.visitor.Reifier.visitClassTypeSignature(Reifier.java:138)
	at sun.reflect.generics.tree.ClassTypeSignature.accept(ClassTypeSignature.java:49)
	at sun.reflect.generics.repository.ClassRepository.getSuperInterfaces(ClassRepository.java:108)
	at java.lang.Class.getGenericInterfaces(Class.java:913)
	at org.springframework.core.ResolvableType.getInterfaces(ResolvableType.java:471)
	at org.springframework.core.GenericTypeResolver.buildTypeVariableMap(GenericTypeResolver.java:265)
	at org.springframework.core.GenericTypeResolver.getTypeVariableMap(GenericTypeResolver.java:242)
	at org.springframework.data.util.ClassTypeInformation.getTypeVariableMap(ClassTypeInformation.java:114)
	at org.springframework.data.util.ClassTypeInformation.getTypeVariableMap(ClassTypeInformation.java:103)
	at org.springframework.data.util.ClassTypeInformation.<init>(ClassTypeInformation.java:92)
	at org.springframework.data.util.ClassTypeInformation.lambda$from$1(ClassTypeInformation.java:70)
	at java.util.concurrent.ConcurrentMap.computeIfAbsent(ConcurrentMap.java:324)
	at org.springframework.data.util.ClassTypeInformation.from(ClassTypeInformation.java:70)
	at org.springframework.data.repository.core.support.AbstractRepositoryMetadata.<init>(AbstractRepositoryMetadata.java:58)
	at org.springframework.data.repository.core.support.DefaultRepositoryMetadata.<init>(DefaultRepositoryMetadata.java:52)
	at org.springframework.data.repository.core.support.AbstractRepositoryMetadata.getMetadata(AbstractRepositoryMetadata.java:73)
	at org.springframework.data.repository.config.RepositoryConfigurationExtensionSupport.getRepositoryConfigurations(RepositoryConfigurationExtensionSupport.java:98)
	at org.springframework.data.repository.config.RepositoryConfigurationDelegate.registerRepositoriesIn(RepositoryConfigurationDelegate.java:121)
	at org.springframework.boot.autoconfigure.data.AbstractRepositoryConfigurationSourceSupport.registerBeanDefinitions(AbstractRepositoryConfigurationSourceSupport.java:60)
	at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.lambda$loadBeanDefinitionsFromRegistrars$1(ConfigurationClassBeanDefinitionReader.java:358)
	at java.util.LinkedHashMap.forEach(LinkedHashMap.java:684)
	at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsFromRegistrars(ConfigurationClassBeanDefinitionReader.java:357)
	at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:145)
	at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(ConfigurationClassBeanDefinitionReader.java:117)
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:328)
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:233)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:273)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:93)
	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:694)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:532)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:327)
	at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:139)
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:99)
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:117)
	at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:108)
	at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:190)
	at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:132)
	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:246)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:227)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:289)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:291)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:246)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:221)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Caused by: java.lang.ClassNotFoundException: io.ebean.bean.EntityBean
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 78 more

The solution is to replace the idea entitybean enhancement plug-in. My computer is replaced with entitybean 10. X enhancement

Mac idea springboot project reported an error

Class JavaLaunchHelper is implemented in both /Library/Java/JavaVirtualMachines/jdk1.8.0_ 144.jdk/Contents/Home/bin/java (0x10dd324c0) and /Library/Java/JavaVirtualMachines/jdk1.8.0_ 144.jdk/contents/home/jre/lib/libinstrument.dylib error

To solve the problem, you need to set the idea custom properties. Click Help on the navigation bar and select Edit custom properties,

For the first time, there is no properties file. At this time, the following interface will pop up in idea to prompt you to create it. Click Create directly.

Write idea. No. launcher = true in idea.properties, and then restart idea.

When idea executes the command, an error is reported: CreateProcess error = 2. The system cannot find the specified file

Problem description

Error running ' mvn install:install-file -DgroupId=xxx.xxx.xxx -DartifactId=myArtifactId -Dversion=0.7.0 -Dpackaging=jar -Dfile=E:\myProject.jar ': Cannot run program "mvn" (in directory "E:\javawarkspace\webhisprotal\ips-portal-admin\hsa-ips-admin-biz\src\main\java\cn\hsa\ips\admin"): CreateProcess error=2, The system cannot find the specified file . However, it can be executed normally in the command line window.

Problem solving

When using the idea command, the prefix cannot have extra spaces. Note the beginning of the command: 'MVN install: install file... , there is a space here. Cause program exception.

SpringCloud: Error creating bean with name ‘configurationPropertiesBeans‘

[problem phenomenon]

When the springcloud system is built in the idea, a red error is prompted at runtime:


org.springframework.beans.factory.BeanCreationException: 
Error creating bean with name 'configurationPropertiesBeans' defined in class path resource 
[org/springframework/cloud/autoconfigure/ConfigurationPropertiesRebinderAutoConfiguration.class]: 
Post-processing of merged bean definition failed; nested exception is java.lang.IllegalStateException: 
Failed to introspect Class 
[org.springframework.cloud.context.properties.ConfigurationPropertiesBeans] 
from ClassLoader [sun.misc.Launcher$AppClassLoader@18b4aac2]

......

Caused by: java.lang.IllegalStateException: 
Failed to introspect Class 
[org.springframework.cloud.context.properties.ConfigurationPropertiesBeans] 
from ClassLoader [sun.misc.Launcher$AppClassLoader@18b4aac2]

......

Caused by: java.lang.NoClassDefFoundError: 
org/springframework/boot/context/properties/ConfigurationBeanFactoryMetadata

......

Caused by: java.lang.ClassNotFoundException: 
org.springframework.boot.context.properties.ConfigurationBeanFactoryMetadata

[reason]

This is a very common problem in the spring cloud system because the spring boot version is incompatible with the spring cloud version.

[solution]

The spring boot version and spring cloud version should be matched in strict accordance with the official version. Link to the official website:
https://spring.io/projects/spring-cloud

Different clouds need different boot versions, as shown in the figure:

Example of version change:

after version replacement, reload all Maven items, as shown in the figure:

If an error is still reported, re-execute the MVN clean package

IDEA Error: clear read-only status [How to Solve]

My environment is MAC
I changed the login user of idea, changed the directory location and directory name of the code

Error reporting.idea idea: clear read only status
Maven error reporting

Maven resources compiler: Failed to copy

I’m directly in the directory

chmod -Rf 777 *
chmod -Rf 777.*

solve

IDEA maven Config MYSQL Connection Error: Could not create connection to database server.

Error message

2021.2\lib\idea_rt.jar;E:\IDEA\IDEA\IntelliJ IDEA 2021.2\plugins\junit\lib\junit5-rt.jar;E:\IDEA\IDEA\IntelliJ IDEA 2021.2\plugins\junit\lib\junit-rt.jar;E:\JDK1.8.301\jre\lib\charsets.jar;E:\JDK1.8.301\jre\lib\deploy.jar;E:\JDK1.8.301\jre\lib\ext\access-bridge-64.jar;E:\JDK1.8.301\jre\lib\ext\cldrdata.jar;E:\JDK1.8.301\jre\lib\ext\dnsns.jar;E:\JDK1.8.301\jre\lib\ext\jaccess.jar;E:\JDK1.8.301\jre\lib\ext\jfxrt.jar;E:\JDK1.8.301\jre\lib\ext\localedata.jar;E:\JDK1.8.301\jre\lib\ext\nashorn.jar;E:\JDK1.8.301\jre\lib\ext\sunec.jar;E:\JDK1.8.301\jre\lib\ext\sunjce_provider.jar;E:\JDK1.8.301\jre\lib\ext\sunmscapi.jar;E:\JDK1.8.301\jre\lib\ext\sunpkcs11.jar;E:\JDK1.8.301\jre\lib\ext\zipfs.jar;E:\JDK1.8.301\jre\lib\javaws.jar;E:\JDK1.8.301\jre\lib\jce.jar;E:\JDK1.8.301\jre\lib\jfr.jar;E:\JDK1.8.301\jre\lib\jfxswt.jar;E:\JDK1.8.301\jre\lib\jsse.jar;E:\JDK1.8.301\jre\lib\management-agent.jar;E:\JDK1.8.301\jre\lib\plugin.jar;E:\JDK1.8.301\jre\lib\resources.jar;E:\JDK1.8.301\jre\lib\rt.jar;C:\Users\13288\Desktop\heiMaProject\springIOC_Anno20210824\target\test-classes;C:\Users\13288\.m2\repository\mysql\mysql-connector-java\5.1.32\mysql-connector-java-5.1.32.jar;C:\Users\13288\.m2\repository\junit\junit\4.11\junit-4.11.jar;C:\Users\13288\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Users\13288\.m2\repository\com\alibaba\druid\1.1.10\druid-1.1.10.jar;C:\Users\13288\.m2\repository\c3p0\c3p0\0.9.1.2\c3p0-0.9.1.2.jar" com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 com.sadhu.config.DataSourseConfiguration,test1
八月 24, 2021 5:19:38 下午 com.mchange.v2.log.MLog <clinit>
信息: MLog clients using java 1.4+ standard logging.
八月 24, 2021 5:19:39 下午 com.mchange.v2.c3p0.C3P0Registry banner
信息: Initializing c3p0-0.9.1.2 [built 21-May-2007 15:04:56; debug?true; trace: 10]
八月 24, 2021 5:19:39 下午 com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
信息: Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> 31snbdajx58efk1sewirk|379619aa, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> null, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 31snbdajx58efk1sewirk|379619aa, idleConnectionTestPeriod -> 0, initialPoolSize -> 3, jdbcUrl -> jdbc:mysql://localhost:33061, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 15, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 3, numHelperThreads -> 3, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> null, properties -> {user=******, password=******}, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
八月 24, 2021 5:20:09 下午 com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask run
警告: com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@7ec906a6 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: 
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
	at sun.reflect.GeneratedConstructorAccessor6.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
	at com.mysql.jdbc.Util.getInstance(Util.java:383)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1023)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:997)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:983)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:928)
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2576)
	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2309)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
	at sun.reflect.GeneratedConstructorAccessor7.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:419)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)
	at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
	at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
	at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
	at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Caused by: java.lang.NullPointerException
	at com.mysql.jdbc.ConnectionImpl.getServerCharset(ConnectionImpl.java:3299)
	at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1967)
	at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1893)
	at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1287)
	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2494)
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2527)
	... 17 more

八月 24, 2021 5:20:09 下午 com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask run
警告: com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@47d734db -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: 
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
	at sun.reflect.GeneratedConstructorAccessor6.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
	at com.mysql.jdbc.Util.getInstance(Util.java:383)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1023)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:997)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:983)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:928)
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2576)
	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2309)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
	at sun.reflect.GeneratedConstructorAccessor7.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:419)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)
	at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
	at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
	at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
	at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Caused by: java.lang.NullPointerException
	at com.mysql.jdbc.ConnectionImpl.getServerCharset(ConnectionImpl.java:3299)
	at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1967)
	at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1893)
	at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1287)
	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2494)
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2527)
	... 17 more

八月 24, 2021 5:20:09 下午 com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask run
警告: com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@3f96684d -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: 
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
	at sun.reflect.GeneratedConstructorAccessor6.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
	at com.mysql.jdbc.Util.getInstance(Util.java:383)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1023)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:997)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:983)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:928)
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2576)
	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2309)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
	at sun.reflect.GeneratedConstructorAccessor7.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:419)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)
	at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
	at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
	at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
	at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Caused by: java.lang.NullPointerException
	at com.mysql.jdbc.ConnectionImpl.getServerCharset(ConnectionImpl.java:3299)
	at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1967)
	at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1893)
	at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1287)
	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2494)
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2527)
	... 17 more


java.sql.SQLException: Connections could not be acquired from the underlying database!

	at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:529)
	at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
	at com.sadhu.config.DataSourseConfiguration.test1(DataSourseConfiguration.java:17)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
	at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1319)
	at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)
	at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)
	... 24 more


Process finished with exit code -1

reason

The package version of the connection data is too low

Solution:

You can use a higher version

after modification, you can pass

Error command line is too long when idea project is started [How to Solve]

Error Message:
Error running ‘****’
Error running****. Command line is too long.
Shorten the command line via JAR manifest or via a classpath file and rerun.

Solution:
1. Click Edit Configurations

2.Click Environment

3. Modify Shorten command kine

[Solved] IDEA Error: Connection refused to host: 127.0.0.1;

Solution:

Check whether the JDK when you import Maven is local, as shown in the figure below. After you change it

Error in idea unit test command line is too long

Question

Recently, I changed the computer and reconfigured the development environment. During unit testing, I found that the idea reported an error

Error running '*******Test.******' 
Command line is too ling. Shorten command line for ******* or also for JUnit default configuration.

Solution

Edit the workspace.xml tag under the project. Idea

<component name=“PropertiesComponent”>

Add next

<property name="dynamic.classpath" value="true" />

Upgrade to IntelliJ idea 2021.2 and start the project with an error

Problem description solution

Problem description

Upgrade to IntelliJ idea 2021.2 and start the project with an error.

Unrecognized option: --add-opens=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED

Solution

File – project structure,
modify as shown in the figure

Resolve the idea error unable to Ping server at localhost: 1099 exception

Unable to Ping server at localhost: 1099
the solutions mentioned on the Internet are the first two, but mine is the third. I hope small partners can avoid the pit
1. The version of Tomcat and JDK matches
port 2 is occupied
3 check the idea configuration Tomcat. VM options cannot have spaces before and after the equals sign
(if there are spaces before and after the equals sign, there will always be an error.)

IDEA reports an error. Error XXX reports an error. The class cannot be found

Scene description

When a relies on B to run a project, the class file in B project cannot be found

The project dependency is intact. There is no problem that the class cannot be found, but an error is reported during operation

Solution:
check whether the JDK configured in idea is consistent with the environment, and whether project B is a runnable project. If it is a runnable project, add the following contents to the POMfile (this problem is caused by bloggers)

<plugin>
  <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-maven-plugin</artifactId>
   <configuration>
       <mainClass>com.xxx</mainClass>
       <skip>true</skip>
   </configuration>
</plugin>

someone runs successfully after checking the following

If there are other solutions, please leave a message

ProgrammerAH

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