Category Archives: JAVA

[Solved] Powermock error: Java.Lang.linkageerror: load constraint violation

Use powermock to report an error Java Lang. linkageerror: load constraint violation

Error reporting information (limited to deletion of space): analysis and solution extension

Error reporting information (limited to deletion of space):

java.lang.LinkageError: Loading constraint violation: loaders“org/powermock/core/classloader/javassist/JavassistMockClassLoader@47ab16ce”先前已启动由装入器“com/ibm/oti/vm/BootstrapClassLoader@ba626924”定义的名为“javax/security/auth/x500/X500Principal”的另一种类型的装入

\tat java.lang.ClassLoader.defineClassImpl(Native Method)
\tat java.lang.ClassLoader.defineClass(ClassLoader.java:346)
\tat org.powermock.core.classloader.javassist.JavassistMockClassLoader.loadUnmockedClass(JavassistMockClassLoader.java:90)
\tat org.powermock.core.classloader.MockClassLoader.loadClassByThisClassLoader(MockClassLoader.java:104)
\tat 、ock.core.MockInvocation.init(MockInvocation.java:31)
\tat org.powermock.core.MockInvocation.<init>(MockInvocation.java:22)
\tat org.powermock.core.MockGateway.doMethodCall(MockGateway.java:155)
\tat org.powermock.core.MockGateway.methodCall(MockGateway.java:138)

analysis

java.Lang.linkageerror this exception is often encountered in applications using multiple classloaders
the reason for this error is the class conflict caused by the cross use of class classes with the same qualified name after being loaded by multiple different classloaders. Classes with the same qualified name belong to different class instances in different classloaders. When loading a class, the JVM needs to load all imported classes. In this case, if there is a class with the same qualified name in the custom classloader as that in the parent classloader, Java. Net will be thrown Lang.LinkageError.
from the error message, you can see that the javax/security/auth/X500/X500 principal class is loaded by the classloader and bootstrapclassloader customized by powermock at the same time.

Solution:

Use @powermockignore to make javassistmockclassloader ignore the loading of javax/security/auth/X500/X500 principal:

@PowerMockIgnore({"javax.security.*"})

[Solved] Activity jump permission UID Error: ActivityTaskmanager: Permission Denied

Scenario.
Settings application’s interface, pulling up Dialer’s interface reports an error.

Error Messages:

//Fail log：Settings->ApnEditorActivity
01-11 16:46:07.938 1044 6380 W ActivityTaskManager: Permission Denial: package=com.android.settings does not belong to uid=1001
//Pass log: Settings->ApnSettingsActivity
01-11 16:46:03.997 1044 1694 I ActivityTaskManager: START u0 {act=android.intent.action.CALL_BUTTON flg=0x10000000 cmp=com.android.dialer/.app.DialpadActivity} from uid 1000

UI corresponding process configuration

<!--AndroidManifest.xml-->
<activity android:name="Settings$ApnEditorActivity"
    android:process="com.android.phone">

Cause analysis:

UI on COM android. Settings, Android: process = “com. Android. Phone” is configured, and they are in different processes.

Source code reference: XRef:/packages/apps/settings/androidmanifest xml (revision 939136b)

<!--xref: /packages/apps/Settings/AndroidManifest.xml (revision 939136b3)-->
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:androidprv="http://schemas.android.com/apk/prv/res/android"
        package="com.android.settings"
        coreApp="true"
        android:sharedUserId="android.uid.system">

The settings application is in system and the phone belongs to radio

adb shell
top # Check the progress

// top
PID USER         PR  NI VIRT  RES  SHR S[%CPU] %MEM     TIME+ ARGS
6558 system    20 0 1.0G 137M 110M S 0.0 15.6 0:06.92 com.android.settings
6138 radio        20   0 1.1G 113M  98M S  0.3  12.9   1:19.43 com.android.phone

Solution:
According to the log ActivityTaskManager: Permission Denial: package=com.android.settings does not belong to uid=1001, it should be a package and process mismatch. Remove the configuration of android:process=”com.android.phone”.

javaweb Connect Datas Error: che.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1444)

1. Jar package is not imported
2 Multiple versions conflict
3 Version mismatch between idea and Tomcat

java.lang.ClassNotFoundException: com.mysql.cj.jdbc.Driver
	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1444)
	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1252)

Error reporting check

1. Check whether you have introduced MySQL-connector-Java.Jar package

This is used to link the database

2. Check the position of the bag

be sure to check

3. See if there are more spaces in the incoming string

serviceimpl inherits generic public impl startup error: ClassCastException (Mybatis-plus version Issue)

Project scenario:

Mybatis plus version: 3.4.3
create abstract general services for service classes and service implementation classes
eg:

service port: service extends AbstracService<T>
service: serviceimpl extends  AbstracServiceImpl<M,T> implements service 
Abstract Common Service Interface: AbstracService<T extends xxBaseEntity> extends IService<T>
Abstract Common Service Interface Implementation: AbstracServiceImpl<M extends BaseMapper<T>,T extends xxBaseEntity> extends ServiceImpl<M, T> implements AbstracService<T>

Problem Description.
Startup error message:
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [cn.xx.xx.xx.service.impl.ServiceImpl]: Constructor threw exception; nested exception is java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:224)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1326)
… 157 common frames omitted
Caused by: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
at com.baomidou.mybatisplus.extension.service.impl.ServiceImpl.currentModelClass(ServiceImpl.java:88)
at com.baomidou.mybatisplus.extension.service.impl.ServiceImpl.(ServiceImpl.java:62)
at cn.lztl.assp.mall.service.impl.AbstractPromotionsServiceImpl.(AbstractPromotionsServiceImpl.java:38)
at cn.lztl.assp.mall.service.impl.ServiceImpl.(SeckillServiceImpl.java:51)
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 org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:211)
… 159 common frames omitted

Solution:
Update mybatis-plus version to version 3.4.3.2 or later.
Introduce dependency com.baomidou.mybatisplus.extension section must be version 3.4.3.2 onwards

Rancher application service error: request entity too large

When request entity too large occurs, it is because the transport stream exceeds 1m.

1. It is necessary to set parameters in ingress of rancher.

Configuration note: nginx.ingress.kubernetes.io/proxy-body-size

2. Springboot 2.0 adds configuration to the configuration file

spring.servlet.multipart.max-file-size=1024MB
spring.servlet.multipart.max-request-size=1024MB

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

Springboot solves swagger UI/index HTML Access Error 404

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

Swagger address in project

Solution:

Adds the address of the specified static resource

@Configuration
public class WebMvcConfig extends WebMvcConfigurationSupport {

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

[Solved] spingboot Error: I/O error on POST request for “9411/api/v2/spans“: connect timed out

Springboot error I/O error on post request for“ http://10.10.195.199:9411/api/v2/spans “: connect timed out; nested exception is java.net.SocketTimeoutException: connect timed out

Problem background solution experience Lyric: a sack of love and happiness

Problem background

When using Zipkin, the following error occurs when accessing the URL

2022-01-11 11:22:35.554  WARN [service-one,,,] 40592 --- [ender@131ff6fa}] z.r.AsyncReporter$BoundedAsyncReporter   : Spans were dropped due to exceptions. All subsequent errors will be logged at FINE level.
2022-01-11 11:22:35.557  WARN [service-one,,,] 40592 --- [ender@131ff6fa}] z.r.AsyncReporter$BoundedAsyncReporter   : Dropped 1 spans due to ResourceAccessException(I/O error on POST request for "http://10.10.195.199:9411/api/v2/spans": connect timed out; nested exception is java.net.SocketTimeoutException: connect timed out)

org.springframework.web.client.ResourceAccessException: I/O error on POST request for "http://10.10.195.199:9411/api/v2/spans": connect timed out; nested exception is java.net.SocketTimeoutException: connect timed out
	at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:751) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.cloud.sleuth.zipkin2.sender.ZipkinRestTemplateWrapper.doExecute(ZipkinRestTemplateSenderConfiguration.java:228) ~[spring-cloud-sleuth-zipkin-2.2.0.RELEASE.jar:2.2.0.RELEASE]
	at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:644) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.cloud.sleuth.zipkin2.sender.RestTemplateSender.post(RestTemplateSender.java:129) ~[spring-cloud-sleuth-zipkin-2.2.0.RELEASE.jar:2.2.0.RELEASE]
	at org.springframework.cloud.sleuth.zipkin2.sender.RestTemplateSender$HttpPostCall.doExecute(RestTemplateSender.java:142) ~[spring-cloud-sleuth-zipkin-2.2.0.RELEASE.jar:2.2.0.RELEASE]
	at org.springframework.cloud.sleuth.zipkin2.sender.RestTemplateSender$HttpPostCall.doExecute(RestTemplateSender.java:132) ~[spring-cloud-sleuth-zipkin-2.2.0.RELEASE.jar:2.2.0.RELEASE]
	at zipkin2.Call$Base.execute(Call.java:380) ~[zipkin-2.19.0.jar:na]
	at zipkin2.reporter.AsyncReporter$BoundedAsyncReporter.flush(AsyncReporter.java:285) ~[zipkin-reporter-2.11.0.jar:na]
	at zipkin2.reporter.AsyncReporter$Flusher.run(AsyncReporter.java:354) [zipkin-reporter-2.11.0.jar:na]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_172]
Caused by: java.net.SocketTimeoutException: connect timed out
	at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method) ~[na:1.8.0_172]
	at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85) ~[na:1.8.0_172]
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_172]
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_172]
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_172]
	at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[na:1.8.0_172]
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_172]
	at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_172]
	at sun.net.NetworkClient.doConnect(NetworkClient.java:175) ~[na:1.8.0_172]
	at sun.net.www.http.HttpClient.openServer(HttpClient.java:463) ~[na:1.8.0_172]
	at sun.net.www.http.HttpClient.openServer(HttpClient.java:558) ~[na:1.8.0_172]
	at sun.net.www.http.HttpClient.<init>(HttpClient.java:242) ~[na:1.8.0_172]
	at sun.net.www.http.HttpClient.New(HttpClient.java:339) ~[na:1.8.0_172]
	at sun.net.www.http.HttpClient.New(HttpClient.java:357) ~[na:1.8.0_172]
	at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:1220) ~[na:1.8.0_172]
	at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1156) ~[na:1.8.0_172]
	at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1050) ~[na:1.8.0_172]
	at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:984) ~[na:1.8.0_172]
	at org.springframework.http.client.SimpleBufferingClientHttpRequest.executeInternal(SimpleBufferingClientHttpRequest.java:76) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:53) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:742) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	... 9 common frames omitted

Solution

1. The firewall is not turned off

systemctl stop firewalld

Experience

1. I was tired of finding the problem. Another time, I just introduced Zipkin dependency, which was not used, and a similar error occurred.

Springboot thymeleaf Error: Exception processing template “table/dynamic_table”: Error resolving template [common]…

1. Error reporting:

[THYMELEAF][http-nio-8080-exec-3] Exception processing template "table/dynamic_table": Error resolving template [common], template might not exist or might not be accessible by any of the configured Template Resolvers (template: "table/dynamic_table" - line 17, col 10)

2. Occurrence

An error is reported when thymeleaf introduces a public page

3. Reasons for error reporting

Original code:

<div th:replace="common :: #leftmenu"></div>

Error report caused by not adding a path

After modification:

<div th:replace="table/common :: #leftmenu"></div>

Jjwt error: ERROR 9856 — [nio-8083-exec-2] o.a.c.c. [. [. [. [/]. [dispatch server]

**

Solve jjwt generation error

**
recently, when learning springboot + JWT + Vue, an error occurred while generating JWT. The error code is as follows:

2022-01-07 11:17:32.335 ERROR 9856 --- [nio-8083-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Filter execution threw an exception] with root cause

java.lang.ClassNotFoundException: javax.xml.bind.DatatypeConverter
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[na:na]
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188) ~[na:na]
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[na:na]
	at io.jsonwebtoken.impl.Base64Codec.decode(Base64Codec.java:26) ~[jjwt-0.9.1.jar:0.9.1]
	at io.jsonwebtoken.impl.DefaultJwtBuilder.signWith(DefaultJwtBuilder.java:99) ~[jjwt-0.9.1.jar:0.9.1]
	at com.okwind.utils.JwtUtils.generateToken(JwtUtils.java:31) ~[classes/:na]
	at com.okwind.security.LoginSuccessHandler.onAuthenticationSuccess(LoginSuccessHandler.java:32) ~[classes/:na]

Analysis error code: at com okwind.utils.JwtUtils. Generatetoken (jwtutils.Java: 31) ~ [classes/: Na] knows that the error occurred in jwtutils Generatetoken (jwtutils.Java: 31) is on line 31 of the tool class.

 26        return Jwts.builder()
 27               .setHeaderParam("typ", "JWT")
 28               .setSubject(username)
 29               .setIssuedAt(nowDate)
 30               .setExpiration(expireDate)
 31               .signWith(SignatureAlgorithm.HS256, app_secret)
 32               .compact();

It means that an exception occurred in generateToken() and it is related to SignatureAlgorithm.HS256.
after analysis, it is referenced:

        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.1</version>
        </dependency>

jjwt version 0.91 is not supported for new JDK versions. There are two solutions.

Method 1: jdk drops to below 11.
Method 2: keep the jdk version unchanged from the higher version and introduce in pom.xml.

<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt</artifactId>
    <version>0.9.1</version>
</dependency>
<dependency>
    <groupId>javax.xml.bind</groupId>
    <artifactId>jaxb-api</artifactId>
    <version>2.4.0-b180830.0359</version>
</dependency>
<dependency>
    <groupId>com.sun.xml.bind</groupId>
    <artifactId>jaxb-impl</artifactId>
    <version>3.0.0-M4</version>
</dependency>
<dependency>
    <groupId>com.sun.xml.bind</groupId>
    <artifactId>jaxb-core</artifactId>
    <version>3.0.0-M4</version>
</dependency>
<dependency>
    <groupId>javax.activation</groupId>
    <artifactId>activation</artifactId>
    <version>1.1.1</version>
</dependency>

So far, the problem is solved.

[Solved] ### Error building SqlSession. ### The error may exist in com/atguigu/dao/SysUserMapper.xml ### Caus 

Error building SqlSession.
The error may exist in com/atguigu/dao/SysUserMapper.xml
Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: java.io.IOException: Could not find resource com/atguigu/dao/SysUserMapper.xml

In POM.XML:

<build>
    <!--Configure resources in build, to prevent our resource export from failing-->
    <resources>
        <resource>
            <directory>src/main/resources</directory>
            <includes>
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
            <filtering>true</filtering>
        </resource>
        <resource>
            <directory>src/main/java</directory>
            <includes>
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
            <filtering>true</filtering>
        </resource></resources>
</build>