Tag Archives: java

How to Solve SSM JSON Chinese Messy Code Issue

Solution:

Add the configuration <mvc:message-converters register-defaults=“true”> in mvc:annotation-driven of sprinmvc-servlet.xml.

The codes are as below:

Unified solution to json Chinese messy code problem<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        https://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        https://www.springframework.org/schema/mvc/spring-mvc.xsd">
    <!--springmvc 统一解决json中文乱码问题-->
    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8"/>
            </bean>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="objectMapper">
                    <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                        <property name="failOnEmptyBeans" value="false"/>
                    </bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

</beans>

[Solved] Springboot Package jar and Startup Error: It was loaded from the following location

Previously, when using springboot to develop the system, the @Resouse annotation was used. There was no exception during the idea runtime, but the jar package conflict was reported when the deployment was packaged.

09:07:51.234 [main] ERROR o.s.b.d.LoggingFailureAnalysisReporter - [report,40] - 

***************************
APPLICATION FAILED TO START
***************************

Description:

An attempt was made to call a method that does not exist. The attempt was made from the following location:

    org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.<init>(CommonAnnotationBeanPostProcessor.java:664)

The following method did not exist:

    'java.lang.String javax.annotation.Resource.lookup()'

The method's class, javax.annotation.Resource, is available from the following locations:

    jar:file:/C:/vic/vic-admin.jar!/BOOT-INF/lib/jsr250-api-1.0.jar!/javax/annotation/Resource.class
    jar:file:/C:/vic/vic-admin.jar!/BOOT-INF/lib/jakarta.annotation-api-1.3.5.jar!/javax/annotation/Resource.class

The class hierarchy was loaded from the following locations:

    javax.annotation.Resource: jar:file:/C:/vic/vic-admin.jar!/BOOT-INF/lib/jsr250-api-1.0.jar!/


Action:

Correct the classpath of your application so that it contains a single, compatible version of javax.annotation.Resource

Reason:

jsr250-api-1.0.jar and jakarta.annotation-api-1.3.5.jar are duplicated

Solution:

Import the following dependency in the pom of Maven. the codes is as below:

<dependency>
    <groupId>javax.annotation</groupId>
    <artifactId>javax.annotation-api</artifactId>
    <version>1.3.2</version>
</dependency>

The purpose of this is to make the system automatically import the latest jar package

How to Solve appium Startup Error (Various Error Messages)

The appium startup keeps reporting errors.
Various errors, such as.

[debug] [ADB] Creating ADB subprocess with args: ["-P",5037,"-s","192.168.0.4:5555","shell","am","instrument","-w","io.appium.uiautomator2.server.test/androidx.test.runner.AndroidJUnitRunner"]
[debug] [WD Proxy] Matched '/status' to command name 'getStatus'
[debug] [WD Proxy] Proxying [GET /status] to [GET http://localhost:8200/wd/hub/status] with no body
[WD Proxy] Got an unexpected response: {"errno":-4077,"code":"ECONNRESET","syscall":"read"}

or:

[debug] [ADB] Running 'D:\003-soft\android-sdk-windows\platform-tools\adb.exe -P 5037 -s 192.168.0.4\:5555 forward --remove tcp\:8200'
[UiAutomator2] Unable to remove port forward 'Error executing adbExec. Original error: 'Command 'D\:\\003-soft\\android-sdk-windows\\platform-tools\\adb.exe -P 5037 -s 192.168.0.4\:5555 forward --remove tcp\:8200' exited with code 1'; Stderr: 'error: listener 'tcp:8200' not found'; Code: '1''
[debug] [BaseDriver] Event 'newSessionStarted' logged at 1659668519002 (11:01:59 GMT+0800 (China Standard Time))

 

The appium.setting installed on the device doesn’t open manually either, and I always thought that was the reason.
Tried to re-install appium and node version, still not working. Finally, here is the solution below:

if automation_name =='UiAutomator2':
    desired_cap['uiautomator2ServerInstallTimeout'] = 20000 This time is changed from 9000 to 20000 and it's fine. It started successfully. After a week of problems, finally good.

[Solved] Hive Run SQL error: mapreduce failed to initiate a task

When running sql in hive, mapreduce fails to launch the task, check the log that APPmaster cannot find the hadoop path.
Solution:
Add the following codes in mapred-site.xml, the error will be solved.

<configuration>
<property>
  <name>yarn.app.mapreduce.am.env</name>
  <value>HADOOP_MAPRED_HOME=/opt/apps/hadoop-3.1.1</value>
</property>
<property>
  <name>mapreduce.map.env</name>
  <value>HADOOP_MAPRED_HOME=/opt/apps/hadoop-3.1.1</value>
</property>
<property>
  <name>mapreduce.reduce.env</name>
  <value>HADOOP_MAPRED_HOME=/opt/apps/hadoop-3.1.1</value>
</property>
 
</configuration>

[Solved] IDEA jsp File Error: pageContext.setAttribute(“APP_PATH“,request.getContextPath());

IDEA jsp file report an error:

pageContext.setAttribute(“APP_PATH“,request.getContextPath())

 

Solution: import the jar package

<!-- https://mvnrepository.com/artifact/javax.servlet/jsp-api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.0</version>
            <scope>provided</scope>
        </dependency>

Linux: How to Solve jdk11+easy poi Export Excel Error

1. Error information

2022-08-09T17:52:02.470+08:00 INFO ctm01favorite.ctm01favorite [http-nio-8866-exec-8] [c.h.s.c.e.StarfishGlobalExceptionHandler$$EnhancerBySpringCGLIB$$c5e30291:121] <8b3bbb91bb4fd066,8b3bbb91bb4fd066> - [info={}] Handler dispatch failed; nested exception is java.lang.InternalError: java.lang.reflect.InvocationTargetException
org.springframework.web.util.NestedServletException: Handler dispatch failed; nested exception is java.lang.InternalError: java.lang.reflect.InvocationTargetException
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1053)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.jasig.cas.client.authentication.AuthenticationFilter.doFilter(AuthenticationFilter.java:242)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.jasig.cas.client.validation.AbstractTicketValidationFilter.doFilter(AbstractTicketValidationFilter.java:237)
    at com.hikvision.sso.client.filter.HikCas20ProxyReceivingTicketValidationFilter.doFilter(HikCas20ProxyReceivingTicketValidationFilter.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.jasig.cas.client.authentication.AuthenticationFilter.doFilter(AuthenticationFilter.java:242)
    at com.hikvision.sso.client.filter.HikAuthenticationFilter.doFilter(HikAuthenticationFilter.java:60)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.jasig.cas.client.session.SingleSignOutFilter.doFilter(SingleSignOutFilter.java:80)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at com.hikvision.starfish.security.web.filter.HttpRequestMehtodFilter.doFilter(HttpRequestMehtodFilter.java:48)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.cloud.sleuth.instrument.web.ExceptionLoggingFilter.doFilter(ExceptionLoggingFilter.java:50)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at brave.servlet.TracingFilter.doFilter(TracingFilter.java:82)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:128)
    at org.springframework.boot.web.servlet.support.ErrorPageFilter.access$000(ErrorPageFilter.java:66)
    at org.springframework.boot.web.servlet.support.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:103)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:121)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:798)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:808)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.InternalError: java.lang.reflect.InvocationTargetException
    at java.desktop/sun.font.FontManagerFactory$1.run(FontManagerFactory.java:86)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at java.desktop/sun.font.FontManagerFactory.getInstance(FontManagerFactory.java:74)
    at java.desktop/java.awt.Font.getFont2D(Font.java:497)
    at java.desktop/java.awt.Font.canDisplayUpTo(Font.java:2250)
    at java.desktop/java.awt.font.TextLayout.singleFont(TextLayout.java:469)
    at java.desktop/java.awt.font.TextLayout.<init>(TextLayout.java:530)
    at org.apache.poi.ss.util.SheetUtil.getDefaultCharWidth(SheetUtil.java:273)
    at org.apache.poi.ss.util.SheetUtil.getColumnWidth(SheetUtil.java:248)
    at org.apache.poi.ss.util.SheetUtil.getColumnWidth(SheetUtil.java:233)
    at org.apache.poi.xssf.usermodel.XSSFSheet.autoSizeColumn(XSSFSheet.java:551)
    at cn.afterturn.easypoi.excel.export.ExcelExportService.createSheetForMap(ExcelExportService.java:221)
    at cn.afterturn.easypoi.excel.export.ExcelExportService.createSheet(ExcelExportService.java:179)
    at cn.afterturn.easypoi.excel.ExcelExportUtil.exportExcel(ExcelExportUtil.java:116)
    at com.hikvision.js.ctm01favorite.service.impl.RoadFeelQueryServiceImpl.exportWifi(RoadFeelQueryServiceImpl.java:284)
    at com.hikvision.js.ctm01favorite.controller.RoadFeelQueryController.exportWifi(RoadFeelQueryController.java:124)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:189)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
    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:800)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038)
    ... 73 common frames omitted
Caused by: java.lang.reflect.InvocationTargetException: null
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
    at java.desktop/sun.font.FontManagerFactory$1.run(FontManagerFactory.java:84)
    ... 99 common frames omitted
Caused by: java.lang.NullPointerException: null
    at java.desktop/sun.awt.FontConfiguration.getVersion(FontConfiguration.java:1262)
    at java.desktop/sun.awt.FontConfiguration.readFontConfigFile(FontConfiguration.java:225)
    at java.desktop/sun.awt.FontConfiguration.init(FontConfiguration.java:107)
    at java.desktop/sun.awt.X11FontManager.createFontConfiguration(X11FontManager.java:719)
    at java.desktop/sun.font.SunFontManager$2.run(SunFontManager.java:367)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at java.desktop/sun.font.SunFontManager.<init>(SunFontManager.java:312)
    at java.desktop/sun.awt.FcFontManager.<init>(FcFontManager.java:35)
    at java.desktop/sun.awt.X11FontManager.<init>(X11FontManager.java:56)
    ... 104 common frames omitted

2. Solutions

Linux Installation your language environment, here I install Chinese language environment

(1) View the current system locale

echo $LANG

(2) Installation (Chinese)

yum groupinstall chinese-support

(3) Change language to Chinese

(1) temporary modification (without restart, but invalid after restart)

LANG="zh_CN.UTF-8"

(2) permanent modification requires server restart

vim /etc/locale.conf
Modify
LANG=zh_CN.UTF-8

[Solved] Windows Redis Error: Could not create server TCP listening socket 127.0.0.1:6379: bind…

An error occurred when redis was started under Windows Environment: could not create server TCP listening socket 127.0.0.1:6379: bind: the operation completed successfully.

Problem Description:
When redis is started in the windows environment today, an error is reported:

Solution:
① run command: redis-cli.exe

② Exit Redis

③ Run the command: redis-server.exe redis.windows.conf

Start successfully!

[Solved] MYSQL Connect Error: Communications link failure

 

org.apache.ibatis.exceptions.PersistenceException: 
### Error updating database.  Cause: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
### The error may exist in mappers/UserMapper.xml
### The error may involve com.chunqiu.mybatis.mapper.UserMapper.insertUser
### The error occurred while executing an update
### Cause: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

When we report the first few lines of error information as shown in the figure above, we can try to exclude common errors on the Internet as below:
1. MySQL data service is not enabled
2. serverTimezone parameter
3. wait_timeout settings

If the error is still reported, check whether there is this line after the error message
Caused by: javax.net.ssl.SSLHandshakeException

Caused by: javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
	at sun.security.ssl.HandshakeContext.<init>(HandshakeContext.java:171)
	at sun.security.ssl.ClientHandshakeContext.<init>(ClientHandshakeContext.java:106)
	at sun.security.ssl.TransportContext.kickstart(TransportContext.java:238)
	at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:410)
	at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:389)
	at com.mysql.cj.protocol.ExportControlled.performTlsHandshake(ExportControlled.java:316)
	at com.mysql.cj.protocol.StandardSocketFactory.performTlsHandshake(StandardSocketFactory.java:188)
	at com.mysql.cj.protocol.a.NativeSocketConnection.performTlsHandshake(NativeSocketConnection.java:99)
	at com.mysql.cj.protocol.a.NativeProtocol.negotiateSSLConnection(NativeProtocol.java:352)
	... 55 more

Solution:
add the parameter usessl = false to the URL

jdbc:mysql://xxx.xxx.xxx.xxx/db?useSSL=false

Cause:
Communications link failure
Caused by: javax.net.ssl
Before MySQL 5.7, the security was low and there were test libraries that any user could connect to, so the official version 5.7 increased the privacy protection. The default value of useSSL = true was used to prevent arbitrary changes to the database. In version 8.0, SSL is still retained and the default value is true, so just set “?useSSL= false” and you’re done!

[Solved] BASE64Encoder Error: Cannot resolve symbol ‘BASE64Encoder’

Question:

Cannot resolve symbol ‘BASE64Encoder’

reason:

After jdk9, the official does not support Import sun.misc.Base64encoder.

Solution:

Method 1: reduce the JDK version to less than 1.8. (not recommended)
Method 2: use the official new jar package import java.util Base64.

The purpose of the following Java class is to modify the corresponding coding format of the file name in different browsers to make it display Chinese correctly.

This is done with sun.misc.BASE64Encoder;

Set BASE64Encoder base64encoder = new BASE64Encoder(); Modify to Base64.Encoder encoder = Base64.getencoder();

And change the encode() method to encodeToString(). Nothing else needs to be modified.

In this way, IDEA will not report an error.

[Solved] asList().add() error: UnsupportedOperationException

ArrayList.add() and aslist().add() problem

using aslist().add() report an error: UnsupportedOperationException


Cause and analysis

asList() is using the internal class ArrayList of Arrays, this internal class does not override the add() method, so the add method used here is the parent class abstract class of the ArrayList class, the add() method here by default is to throw an exception: UnsupportedOperationException

Internal class of arrays

  private static class ArrayList<E> extends AbstractList<E>
        implements RandomAccess, java.io.Serializable
    {
        private static final long serialVersionUID = -2764017481108945198L;
        private final E[] a;

        ArrayList(E[] array) {
            a = Objects.requireNonNull(array);
        }

        @Override
        public int size() {
            return a.length;
        }

        @Override
        public Object[] toArray() {
            return a.clone();
        }

        @Override
        @SuppressWarnings("unchecked")
        public <T> T[] toArray(T[] a) {
            int size = size();
            if (a.length < size)
                return Arrays.copyOf(this.a, size,
                                     (Class<?extends T[]>) a.getClass());
            System.arraycopy(this.a, 0, a, 0, size);
            if (a.length > size)
                a[size] = null;
            return a;
        }

        @Override
        public E get(int index) {
            return a[index];
        }

        @Override
        public E set(int index, E element) {
            E oldValue = a[index];
            a[index] = element;
            return oldValue;
        }

        @Override
        public int indexOf(Object o) {
            E[] a = this.a;
            if (o == null) {
                for (int i = 0; i < a.length; i++)
                    if (a[i] == null)
                        return i;
            } else {
                for (int i = 0; i < a.length; i++)
                    if (o.equals(a[i]))
                        return i;
            }
            return -1;
        }

        @Override
        public boolean contains(Object o) {
            return indexOf(o) != -1;
        }

        @Override
        public Spliterator<E> spliterator() {
            return Spliterators.spliterator(a, Spliterator.ORDERED);
        }

        @Override
        public void forEach(Consumer<?super E> action) {
            Objects.requireNonNull(action);
            for (E e : a) {
                action.accept(e);
            }
        }

        @Override
        public void replaceAll(UnaryOperator<E> operator) {
            Objects.requireNonNull(operator);
            E[] a = this.a;
            for (int i = 0; i < a.length; i++) {
                a[i] = operator.apply(a[i]);
            }
        }

        @Override
        public void sort(Comparator<?super E> c) {
            Arrays.sort(a, c);
        }
    }

Add method of ArrayList() class

 public boolean add(E e) {
        ensureCapacityInternal(size + 1);  // Increments modCount!!
        elementData[size++] = e;
        return true;
    }

Add method of AbstractList class

Aslist() uses this method

public void add(int index, E element) {
        throw new UnsupportedOperationException();//This is where the exception is thrown
    }

[Solved] flicksql cdc mysql to kafka Connect Error: org.apache.flink.table.api.ValidationException…

Error Messages: org.apache.flink.table.api.ValidationException: Could not find any factory for identifier 'debezium-json' that implements 'org.apache.flink.table.factories.SerializationFormatFactory' in the classpath.


Check if there is any package that I forgot to import
I didn’t import the flink-json package here

        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-json</artifactId>
            <version>${flink.version}</version>
        </dependency>

The import is successful and Kafka can be connected normally~

[Solved] Nacos Serve Local Startup Error: Error starting Tomcat context. Exception: org.springframework.beans.factory.BeanCre

Environmental Science:

Nacos-server-2.0.4

Windows.8.1

nacos-server-2.0.4\nacos\bin\startup.cmd execute error

Error message: Error starting Tomcat context. Exception: org.springframework.beans.factory.BeanCreationException

Reason for error: Nacos defaults to the cluster startup mode

Modify as shown in the figure to start a single machine

set MODE="standalone"

Start successful

Other solutions:

Start by command

startup.cmd -m standalone