Tag Archives: java

[Solved] Error creating bean with name ‘fileVisitController‘ defined in file

When importing the jar package from nexus into the local project, an error occurred during startup:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 
'fileVisitController' defined in file [D:\dengkun\dengkun_server\dengkun-
api\target\classes\com\dengkun\api\controller\auxiliary\FileVisitController.class]: 
Instantiation of bean failed; nested exception is 
org.springframework.beans.BeanInstantiationException: Failed to instantiate 
[com.dengkun.api.controller.auxiliary.FileVisitController]: Constructor threw exception; 
nested exception is org.apache.ibatis.binding.BindingException: Type interface 
com.dengkun.dao.FileVisitMapper is not known to the MapperRegistry.

After troubleshooting, it is found that the mybatis-conf.xml file in the jar package has the same name as the XML file in other jar packages;

So, change mybatis-conf.xml to mybatis-conf-lct.xml The XML program can start normally

Lotti triggered Java lang.StackOverflowError [How to Solve]

Change Lottie from 2.8.0 in the project Upgrade to version 4.2.0 After the 0 version, the stack memory error suddenly occurred. The last reason was to call the resumeAnimation() method in the onAnimationEnd callback method, and in the resumeAnimation() method, the onAnimationEnd callback method was finally activated into a dead loop.

[Solved] Websocket Error: WebSocket is already in CLOSING or CLOSED state

When the front-end project communicates with the back-end Java websocket for a long time, sometimes the browser will report an error

WebSocket is already in CLOSING or CLOSED state.

This problem may be caused by the data length passed by websocket being greater than 8192   After websocket establishes a connection, the length of JSON passed should be & lt= 8192, otherwise an error will be reported    Websocket is already in closing or closed state.

1. At this point, we can add some code in web.xml to limit the parameter length limit in websocket.

# Limit WebSocket pass data size to 50M
<context-param>
         <param-name>org.apache.tomcat.websocket.textBufferSize</param-name>
         <param-value>5242800</param-value>
</context-param>

<context-param>
         <param-name>org.apache.tomcat.websocket.binaryBufferSize</param-name>
         <param-value>5242800</param-value>
</context-param>

After adding the above code, you can modify the size and length of the transfer parameters of websocket, which is limited to 50m.

2. The above method is not available for the springboot project because there is no web.xml file in the project directory. At this time, we can put the following code into the springboot project under the context directory of the project (or create a new code class or block at will)

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.web.servlet.ServletContextInitializer;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.util.WebAppRootListener;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;

/**
 * Add WebSocket pass data size limit of 50M
 */
@Configuration
@ComponentScan
@EnableAutoConfiguration
public class WebSocketConfig implements ServletContextInitializer {

    //Configure websocket transfer size, 50M
    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        servletContext.addListener(WebAppRootListener.class);
        servletContext.setInitParameter("org.apache.tomcat.websocket.textBufferSize","52428800");
        servletContext.setInitParameter("org.apache.tomcat.websocket.binaryBufferSize","52428800");
    }
}

The above code can solve the problem of websocket is already in closing or closed state

You can successfully modify the size limit of websocket transmission data to 50m.

Note: a problem was found during use. If the above configuration is started with the built-in Tomcat in springboot, there is no problem, but the operation using the external Tomcat after war does not take effect. Finally, it is found that the problem is due to the external Tomcat version. The problem version is tomcat8.0.xx, but there is no problem using tomcat8.5.xx

[Solved] Mapreducer Class Conversion error: java.lang.ClassCastException

An error was reported while writing the mapreducer.
java.lang.ClassCastException: class date2021_11_27_5.Commodity
    at java.lang.Class.asSubclass(Unknown Source)
    at org.apache.hadoop.mapred.JobConf.getOutputKeyComparator(JobConf.java:887)
    at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.init(MapTask.java:1004)
    at org.apache.hadoop.mapred.MapTask.createSortingCollector(MapTask.java:402)
    at org.apache.hadoop.mapred.MapTask.access$100(MapTask.java:81)
    at org.apache.hadoop.mapred.MapTask$NewOutputCollector.<init>(MapTask.java:698)
    at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:770)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
    at org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:243)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
2021-11-29 10:00:26,301 INFO [org.apache.hadoop.mapred.LocalJobRunner] - map task executor complete.
  2021-11-29 10:00:26,302 WARN [org.apache.hadoop.mapred.LocalJobRunner] - job_local49120036_0001
  java.lang.Exception: java.io.IOException: Initialization of all the collectors failed. Error in last collector was :class date2021_11_27_5.Commodity
    at org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:462)
    at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:522)
Caused by: java.io.IOException: Initialization of all the collectors failed. Error in last collector was :class date2021_11_27_5.Commodity
    at org.apache.hadoop.mapred.MapTask.createSortingCollector(MapTask.java:415)
    at org.apache.hadoop.mapred.MapTask.access$100(MapTask.java:81)
    at org.apache.hadoop.mapred.MapTask$NewOutputCollector.<init>(MapTask.java:698)
    at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:770)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
    at org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:243)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassCastException: class date2021_11_27_5.Commodity
    at java.lang.Class.asSubclass(Unknown Source)
    at org.apache.hadoop.mapred.JobConf.getOutputKeyComparator(JobConf.java:887)
    at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.init(MapTask.java:1004)
    at org.apache.hadoop.mapred.MapTask.createSortingCollector(MapTask.java:402)
    ... 10 more

 

How to Solve:
This is because the custom entity class does not implement the WritableComparable<Commodity> interface, or does not override the compareTo method, resulting in a class conversion exception due to lack of serialization.
There is another possibility that
Implementing the WritableComparable<Commodity> interface instead of the WritableComparable<Commodity> interface because of the mapreducer rules
This implementation of two interfaces will result in the above error message when using a custom entity class for the value without problems, but when using a custom entity class for the key
Just reimplement the WritableComparable<Commodity> interface and guide the package
Hadoop specifies that if you implement the Writable and Comparable<Commodity> interfaces, the data of the custom entity class can only be used as value, but if you implement the WritableComparable<Commodity> interface, the data of the custom entity class can be used as both key and value.

JavaFX textarea component error: ArrayIndexOutOfBoundsException

There was a problem with the gadget made before. From time to time, it reported that the array exceeded the boundary, but the specific code could not be located.

Take some time to solve it today.

The effect you want to achieve is like this: multiple threads display messages on the textarea in turn. In order to ensure real-time data update, you need to constantly refresh the textarea component.

The original code is like this

    public void refresh() {
        if(currentServerName == null) {
            //Refuse to refresh
            return;
        }
        setText("");
        appendText(LOG_MAP.getOrDefault(currentServerName, ""));
        setScrollTop(Double.MAX_VALUE);
        
    }

Directly refresh the data in the textarea in an external thread (a thread created by yourself).

After consulting the data, it is found that the container content must be modified in JavaFX’s own thread to ensure that no error will be reported. So wrap it with the platform. The modified code is as follows:

    public void refresh() {
        if(currentServerName == null) {
            //Refuse to refresh
            return;
        }
        setText("");
        appendText(LOG_MAP.getOrDefault(currentServerName, ""));
        setScrollTop(Double.MAX_VALUE);
        Platform.runLater(()->{
            setText("");
            appendText(LOG_MAP.getOrDefault(currentServerName, ""));
            setScrollTop(Double.MAX_VALUE);
        });
    }

[Solved] ClientAbortException: java.io.IOException: Connection reset by peer

Error message:

org.apache.catalina.connector.ClientAbortException: java.io.IOException: Connection reset by peer
	at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:353)
	at org.apache.catalina.connector.OutputBuffer.flushByteBuffer(OutputBuffer.java:783)
	at org.apache.catalina.connector.OutputBuffer.append(OutputBuffer.java:688)
	at org.apache.catalina.connector.OutputBuffer.writeBytes(OutputBuffer.java:388)
	at org.apache.catalina.connector.OutputBuffer.write(OutputBuffer.java:366)
	at org.apache.catalina.connector.CoyoteOutputStream.write(CoyoteOutputStream.java:96)
	at org.springframework.util.StreamUtils$NonClosingOutputStream.write(StreamUtils.java:287)
	at com.fasterxml.jackson.core.json.UTF8JsonGenerator._flushBuffer(UTF8JsonGenerator.java:2177)
	at com.fasterxml.jackson.core.json.UTF8JsonGenerator._writeStringSegments(UTF8JsonGenerator.java:1319)
	at com.fasterxml.jackson.core.json.UTF8JsonGenerator.writeString(UTF8JsonGenerator.java:517)
	at com.fasterxml.jackson.databind.ser.std.StringSerializer.serialize(StringSerializer.java:41)
	at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:808)
	at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeWithoutTypeInfo(MapSerializer.java:764)
	at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:720)
	at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:35)
	at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serializeContents(IndexedListSerializer.java:119)
	at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serialize(IndexedListSerializer.java:79)
	at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serialize(IndexedListSerializer.java:18)
	at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728)
	at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:770)
	at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178)
	at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145)
	at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107)
	at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25)
	at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728)
	at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:770)
	at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178)
	at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728)
	at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:770)
	at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178)
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480)
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:319)
	at com.fasterxml.jackson.databind.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1514)
	at com.fasterxml.jackson.databind.ObjectWriter.writeValue(ObjectWriter.java:1006)
	at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:454)
	at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:104)
	at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:290)
	at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:183)
	at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:78)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:135)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:681)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:764)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:450)
	at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
	at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
	at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
	at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:387)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at cn.aidcloud.base.xss.XssFilter.doFilter(XssFilter.java:58)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:895)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1722)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)
	Suppressed: org.apache.catalina.connector.ClientAbortException: java.io.IOException: 断开的管道
		at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:353)
		at org.apache.catalina.connector.OutputBuffer.flushByteBuffer(OutputBuffer.java:783)
		at org.apache.catalina.connector.OutputBuffer.append(OutputBuffer.java:688)
		at org.apache.catalina.connector.OutputBuffer.writeBytes(OutputBuffer.java:388)
		at org.apache.catalina.connector.OutputBuffer.write(OutputBuffer.java:366)
		at org.apache.catalina.connector.CoyoteOutputStream.write(CoyoteOutputStream.java:96)
		at org.springframework.util.StreamUtils$NonClosingOutputStream.write(StreamUtils.java:287)
		at com.fasterxml.jackson.core.json.UTF8JsonGenerator._flushBuffer(UTF8JsonGenerator.java:2177)
		at com.fasterxml.jackson.core.json.UTF8JsonGenerator.close(UTF8JsonGenerator.java:1220)
		at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:458)
		... 69 common frames omitted
	Caused by: java.io.IOException:
		at sun.nio.ch.FileDispatcherImpl.write0(Native Method)
		at sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java:47)
		at sun.nio.ch.IOUtil.writeFromNativeBuffer(IOUtil.java:93)
		at sun.nio.ch.IOUtil.write(IOUtil.java:65)
		at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:469)
		at org.apache.tomcat.util.net.NioChannel.write(NioChannel.java:135)
		at org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper.doWrite(NioEndpoint.java:1363)
		at org.apache.tomcat.util.net.SocketWrapperBase.doWrite(SocketWrapperBase.java:766)
		at org.apache.tomcat.util.net.SocketWrapperBase.writeBlocking(SocketWrapperBase.java:586)
		at org.apache.tomcat.util.net.SocketWrapperBase.write(SocketWrapperBase.java:530)
		at org.apache.coyote.http11.Http11OutputBuffer$SocketOutputBuffer.doWrite(Http11OutputBuffer.java:547)
		at org.apache.coyote.http11.filters.IdentityOutputFilter.doWrite(IdentityOutputFilter.java:84)
		at org.apache.coyote.http11.Http11OutputBuffer.doWrite(Http11OutputBuffer.java:194)
		at org.apache.coyote.Response.doWrite(Response.java:615)
		at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:340)
		... 78 common frames omitted
Caused by: java.io.IOException: Connection reset by peer
	at sun.nio.ch.FileDispatcherImpl.write0(Native Method)
	at sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java:47)
	at sun.nio.ch.IOUtil.writeFromNativeBuffer(IOUtil.java:93)
	at sun.nio.ch.IOUtil.write(IOUtil.java:65)
	at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:469)
	at org.apache.tomcat.util.net.NioChannel.write(NioChannel.java:135)
	at org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper.doWrite(NioEndpoint.java:1363)
	at org.apache.tomcat.util.net.SocketWrapperBase.doWrite(SocketWrapperBase.java:766)
	at org.apache.tomcat.util.net.SocketWrapperBase.writeBlocking(SocketWrapperBase.java:586)
	at org.apache.tomcat.util.net.SocketWrapperBase.write(SocketWrapperBase.java:530)
	at org.apache.coyote.http11.Http11OutputBuffer$SocketOutputBuffer.doWrite(Http11OutputBuffer.java:547)
	at org.apache.coyote.http11.filters.IdentityOutputFilter.doWrite(IdentityOutputFilter.java:84)
	at org.apache.coyote.http11.Http11OutputBuffer.doWrite(Http11OutputBuffer.java:194)
	at org.apache.coyote.Response.doWrite(Response.java:615)
	at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:340)
	... 103 common frames omitted

Corresponding front-end error net:: err_INCOMPLETE_CHUNKED_ENCODING 200

How to Solve:

After ES re extracts the data, the data of one field becomes particularly large, resulting in a particularly large package when returning to the front end, resulting in too large response data of nginx. Temporary files will be used for processing, but the user does not have the permission to operate this directory, so the service is stopped directly. Finally throw the above error.

Solution:

1. Check the error log of nginx (/data/000x/nginx/logs/error.Log)

2021/12/01 12:05:40 [crit] 66289#0: *680 open() "/data/000x/nginx/proxy_temp/2/02/0000000022" failed (13: Permission denied) while reading upstream, client: 192.16.199.1, server: localhost, request: "POST /api/search/result HTTP/1.1", upstream: "http://127.0.0.1:17803/search/result", host: "192.16.199.20:17002", referrer: "http://192.16.199.20:17002/pc/"

2. To/data/000x/nginx/proxy_Temp grant permission

Done!!!

Lifecyclebase.java: 154 Error [How to Solve]

Error Messages:

Warning: ContainerBase.addChild: start: 
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/HelloS]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:649)
    at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1760)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:618)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:565)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at com.sun.jmx.remote.security.MBeanServerAccessController.invoke(MBeanServerAccessController.java:468)
    at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1487)
    at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:97)
    at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1328)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1427)
    at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:848)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322)
    at sun.rmi.transport.Transport$1.run(Transport.java:177)
    at sun.rmi.transport.Transport$1.run(Transport.java:174)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:556)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:811)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:670)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.UnsupportedClassVersionError: org/springframework/web/SpringServletContainerInitializer : Unsupported major.minor version 52.0 (unable to load class org.springframework.web.SpringServletContainerInitializer)
    at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2961)
    at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1210)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1690)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:270)
    at org.apache.catalina.startup.WebappServiceLoader.loadServices(WebappServiceLoader.java:187)
    at org.apache.catalina.startup.WebappServiceLoader.load(WebappServiceLoader.java:152)
    at org.apache.catalina.startup.ContextConfig.processServletContainerInitializers(ContextConfig.java:1559)
    at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1281)
    at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:889)
    at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:386)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
    at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5380)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 42 more

 

Reason & Solution:

It’s the version problem
Just contacted idea, downloaded the version of 2020.3, created the web version is 5.0, when creating the project can not be modified to reduce the version, and jdk configuration of 1.7, tomcat with 7, so it reported this error. Later, jdk was changed to 1.8 and tomcat was changed to 9 and started normally.
And then continue to reproduce the problem, left for the record, found that only the impact of jdk, jdk1.8 with tomcat7 can also start the project normally.
The long time to do have a love of the old plot, jdk1.7 has been used to the present, too lazy to replace, so ignore the version of the problem.

 

[Solved] java.sql.SQLException: Unsupported character encoding ‘utf-8

An error is reported when running connection pool in idea: java.sql.sqlexception: Unsupported character encoding ‘UTF-8’

//run   
public static void main(String[] args) throws SQLException {
        ConPool pool = new ConPool("mysql");
        pool.initPool(5);
        PoolCon borrow = pool.borrow();
        ResultSet resultSet = borrow.getCon().createStatement().executeQuery("select * from master_tab");
        while (resultSet.next()) {
            System.out.println(resultSet.getString("name"));
        }
    }

Error reporting interface:

java.sql.SQLException: Unsupported character encoding 'utf-8
			'.
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
	at com.mysql.jdbc.ConnectionPropertiesImpl.postInitialization(ConnectionPropertiesImpl.java:2575)
	at com.mysql.jdbc.ConnectionPropertiesImpl.initializeProperties(ConnectionPropertiesImpl.java:2545)
	at com.mysql.jdbc.ConnectionImpl.initializeDriverProperties(ConnectionImpl.java:3143)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:762)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	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:425)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
	at java.sql.DriverManager.getConnection(DriverManager.java:664)
	at java.sql.DriverManager.getConnection(DriverManager.java:247)
	at cn.kgc.base.ConPool.con(ConPool.java:82)
	at cn.kgc.base.ConPool.initPool(ConPool.java:96)
	at cn.kgc.base.ConPool.main(ConPool.java:149)
java.sql.SQLException: Unsupported character encoding 'utf-8
			'.
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
	at com.mysql.jdbc.ConnectionPropertiesImpl.postInitialization(ConnectionPropertiesImpl.java:2575)
	at com.mysql.jdbc.ConnectionPropertiesImpl.initializeProperties(ConnectionPropertiesImpl.java:2545)
	at com.mysql.jdbc.ConnectionImpl.initializeDriverProperties(ConnectionImpl.java:3143)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:762)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	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:425)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
	at java.sql.DriverManager.getConnection(DriverManager.java:664)
	at java.sql.DriverManager.getConnection(DriverManager.java:247)
	at cn.kgc.base.ConPool.con(ConPool.java:82)
	at cn.kgc.base.ConPool.initPool(ConPool.java:96)
	at cn.kgc.base.ConPool.main(ConPool.java:149)
java.sql.SQLException: Unsupported character encoding 'utf-8
			'.
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
	at com.mysql.jdbc.ConnectionPropertiesImpl.postInitialization(ConnectionPropertiesImpl.java:2575)
	at com.mysql.jdbc.ConnectionPropertiesImpl.initializeProperties(ConnectionPropertiesImpl.java:2545)
	at com.mysql.jdbc.ConnectionImpl.initializeDriverProperties(ConnectionImpl.java:3143)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:762)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	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:425)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
	at java.sql.DriverManager.getConnection(DriverManager.java:664)
	at java.sql.DriverManager.getConnection(DriverManager.java:247)
	at cn.kgc.base.ConPool.con(ConPool.java:82)
	at cn.kgc.base.ConPool.initPool(ConPool.java:96)
	at cn.kgc.base.ConPool.main(ConPool.java:149)
java.sql.SQLException: Unsupported character encoding 'utf-8
			'.
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
	at com.mysql.jdbc.ConnectionPropertiesImpl.postInitialization(ConnectionPropertiesImpl.java:2575)
	at com.mysql.jdbc.ConnectionPropertiesImpl.initializeProperties(ConnectionPropertiesImpl.java:2545)
	at com.mysql.jdbc.ConnectionImpl.initializeDriverProperties(ConnectionImpl.java:3143)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:762)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	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:425)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
	at java.sql.DriverManager.getConnection(DriverManager.java:664)
	at java.sql.DriverManager.getConnection(DriverManager.java:247)
	at cn.kgc.base.ConPool.con(ConPool.java:82)
	at cn.kgc.base.ConPool.initPool(ConPool.java:96)
	at cn.kgc.base.ConPool.main(ConPool.java:149)
java.sql.SQLException: Unsupported character encoding 'utf-8
			'.
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
	at com.mysql.jdbc.ConnectionPropertiesImpl.postInitialization(ConnectionPropertiesImpl.java:2575)
	at com.mysql.jdbc.ConnectionPropertiesImpl.initializeProperties(ConnectionPropertiesImpl.java:2545)
	at com.mysql.jdbc.ConnectionImpl.initializeDriverProperties(ConnectionImpl.java:3143)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:762)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	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:425)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
	at java.sql.DriverManager.getConnection(DriverManager.java:664)
	at java.sql.DriverManager.getConnection(DriverManager.java:247)
	at cn.kgc.base.ConPool.con(ConPool.java:82)
	at cn.kgc.base.ConPool.initPool(ConPool.java:96)
	at cn.kgc.base.ConPool.main(ConPool.java:149)
Pool connection object initialization not yet halfway exception

Process finished with exit code -4

Problems found in XML file: <value></value> The code is too long when writing, and the </value> Line breaks were made.

<configuration>
	<datasource id="mysql">
		<property>
			<name>driver</name>
			<value>com.mysql.jdbc.Driver</value>
		</property>
		<property>
			<name>url</name>
			<value>jdbc:mysql://192.168.1.200:3306/master_slave_copy?useSSL=true&amp;useUnicode=true&amp;characterEncoding=utf-8
			</value>//Error
		</property>
		<property>
			<name>username</name>
			<value>root</value>
		</property>
		<property>
			<name>password</name>
			<value>ok</value>
		</property>
	</datasource>
	<datasource id="oracle"></datasource>
</configuration>

Solution: add </value> Adjust to <value> Same line

<configuration>
	<datasource id="mysql">
		<property>
			<name>driver</name>
			<value>com.mysql.jdbc.Driver</value>
		</property>
		<property>
			<name>url</name>
			<value>jdbc:mysql://192.168.1.200:3306/master_slave_copy?useSSL=true&amp;useUnicode=true&amp;characterEncoding=utf-8</value>
		</property>
		<property>
			<name>username</name>
			<value>root</value>
		</property>
		<property>
			<name>password</name>
			<value>ok</value>
		</property>
	</datasource>
	<datasource id="oracle"></datasource>
</configuration>

Run successfully!

Android Error: META-INF/DEPENDENCIES [How to Solve]

3 files found with path ‘META-INF/DEPENDENCIES’.
Adding a packagingOptions block may help, please refer to
https://google.github.io/android-gradle-dsl/current/com.android.build.gradle.internal.dsl.PackagingOptions.html
for more information

Probably means: Error: Multiple files found in OS independent path ‘META-INF/DEPENDENCIES’
Solution:
Add to the build.gradle where the problem occurs

packagingOptions {
    exclude 'META-INF/DEPENDENCIES'
    exclude 'META-INF/NOTICE'
    exclude 'META-INF/LICENSE'
    exclude 'META-INF/LICENSE.txt'
    exclude 'META-INF/NOTICE.txt'
}

The general principle is:

In Android gradle construction, it is not allowed to include the same file with the same path in the output multiple times. In your construction, there are two meta-inf/dependencies files from different places. Since your application does not need this file at all, the easiest way is to tell the construction system to ignore it completely, which is the role of the exclude instruction

Another PickFirst instruction tells the build system to keep one copy; There are some details in Android gradle plug-in 0.7.0: “duplicate files during APK packaging”

[Solved] Sqlyog always reports an error when creating a new connection.

Case 1:

In versions before MySQL 8, the encryption rule is mysql_native_Password, and after MySQL 8, the encryption rule is caching_sha2_password。 There are two ways to solve the problem. The first is to upgrade the graphical interface tool version, and the second is to restore the MySQL user login password encryption rules to MySQL_native_password.
the second solution is as follows. After logging into MySQL database with the command line, execute the following command to modify the user password encryption rules and update the user password. Here, modify the user name as“ root@localhost ”The user password rule of is “mysql_native_password”, and the password value is “OK”, as shown in the figure.

//Using mysql database
USE mysql; 

//change the password rule and password for the 'root'@'localhost' user
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'ok'; 

//refresh permissions
FLUSH PRIVILEGES;

Situation II

The virtual machine MySQL is connected, and you need to perform the authorization operation
authorize the root user:
grant all on. To ‘root’ @ ‘%’ identified by ‘use password’
flush privileges;

[Solved] Error creating bean with name ’emf’ defined in org.ngrinder.infra.config.DatabaseConf

This similar problem has been encountered several times, but you can still find the error every time you report an error. When reporting an error, think about what you modified earlier, and then go to see if the corresponding code has the same path. Or attribute problems. But I can’t find the error report this time. The previous version before my modification can still be started. When I came to work the next day, I reported an error as soon as it was started. It has not been solved yet. If it is solved, the answer will be pasted. The following error reasons:

Code text:

01-Dec-2021 18:58:11.804 信息 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Spring WebApplicationInitializers detected on classpath: [org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration$JerseyWebApplicationInitializer@b0ebd27]
01-Dec-2021 18:58:11.953 信息 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Initializing Spring root WebApplicationContext
01-Dec-2021 18:58:15.892 严重 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.StandardContext.listenerStart 异常将上下文初始化事件发送到类的侦听器实例.[org.springframework.web.context.ContextLoaderListener]
		at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.preparePersistenceUnitInfos(DefaultPersistenceUnitManager.java:470)
		at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.afterPropertiesSet(DefaultPersistenceUnitManager.java:424)
		at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:310)
		at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:319)
		at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1637)
		at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574)
		... 59 more
01-Dec-2021 18:58:15.911 信息 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Closing Spring root WebApplicationContext
	org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'emf' defined in org.ngrinder.infra.config.DatabaseConfig: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Conflicting persistence unit definitions for name 'ngrinder': file:/D:/zaixianStudy/0server/apache-tomcat-8.5.69/webapps/ngrinder-web/WEB-INF/lib/ngrinder-controller-3.4.4.jar, file:/D:/zaixianStudy/0server/apache-tomcat-8.5.69/webapps/ngrinder-web/WEB-INF/classes
		at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1578)
		at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
		at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
		at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
		at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
		at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
		at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
		at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1054)
		at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:829)
		at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538)
		at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:444)
		at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:326)
		at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
		at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4763)
		at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5232)
		at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
		at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:755)
		at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:729)
		at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:695)
		at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1775)
		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.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:291)
		at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
		at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
		at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:483)
		at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:431)
		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.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:291)
		at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
		at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
		at com.sun.jmx.remote.security.MBeanServerAccessController.invoke(MBeanServerAccessController.java:468)
		at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468)
		at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
		at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309)
		at java.security.AccessController.doPrivileged(Native Method)
		at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1408)
		at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
		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 sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357)
		at sun.rmi.transport.Transport$1.run(Transport.java:200)
		at sun.rmi.transport.Transport$1.run(Transport.java:197)
		at java.security.AccessController.doPrivileged(Native Method)
		at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
		at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
		at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
		at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683)
		at java.security.AccessController.doPrivileged(Native Method)
		at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
		at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
		at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
		at java.lang.Thread.run(Thread.java:748)
	Caused by: java.lang.IllegalStateException: Conflicting persistence unit definitions for name 'ngrinder': file:/D:/zaixianStudy/0server/apache-tomcat-8.5.69/webapps/ngrinder-web/WEB-INF/lib/ngrinder-controller-3.4.4.jar, file:/D:/zaixianStudy/0server/apache-tomcat-8.5.69/webapps/ngrinder-web/WEB-INF/classes

The problem has been solved. Let’s talk about my handling method. I won’t talk about bullshit. I’ve met those interfaces with the same URL, no annotation, the same method name, wrong package, different versions, repeated POM files or inconsistent versions, and what reset projects empty Maven and download again. I’ve met them many times, I’ve tried it all. The answers on the Internet are the same, copy around. My situation is like this. I can run on the first day, but I can’t do it on the second day. I don’t have a clue about the error reported. I checked the GIT code again and again and found that there is nothing wrong and I can’t start. So I did the following work:

1. Find the local tomcat, delete the jar package in webapp and the compiled project file, delete the Tomcat configuration in the project, and reconfigure it

2. Check whether Maven is configured correctly, whether Maven is its own, whether the settings.xml file is correct, and the warehouse. There are many local versions of tomcat, Maven and JDK. I downloaded a lot to test the difference between versions before. After checking, click the navigation bar on the right, circle, refresh and brush several times

3. Click File >>>> ProjectStructure>>> Modules, delete all and reintroduce

4. Check whether the artifacts are correct, and there must be all of them

5. On the right navigation bar, refresh maven, clear, complex, package and run, which solves my problem.

The above is my solution. I have no problem with the code. If there is a problem with the code, don’t use it