如何更正 spring boot 应用程序的类路径，使其包含单个兼容版本的 javax.persistence.PersistenceContext？

Question

I am trying to add a participantRepository interface (which implements CrudRepository) to my spring boot application. But the basic code for this interface gives an error when it is run saying that the classpath of the application must be corrected. How can I do this and is there another modification I can do to run the code correctly?

//Participant class

package com.example.spring2.participants;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import javax.persistence.Entity;
import javax.persistence.Id;
import java.util.List;

@Entity
public class Participant {

    @Id
    private String name;
    private int age;
    private String job;

    @Autowired
    private ParticipentService participentService;

    public Participant() {
    }

    public Participant(String name, int age, String job) {
        this.name = name;
        this.age = age;
        this.job = job;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getJob() {
        return job;
    }

    public void setJob(String job) {
        this.job = job;
    }

}

//ParticipantController class

package com.example.spring2.participants;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
public class ParticipantController {


    @Autowired
    private ParticipentService participentService;


    @RequestMapping("/people")
    public List<Participant> viewPeople(){
        return participentService.getParticipants();
    }

    @RequestMapping("/people/{name}")
    public Participant getAParticipant(@PathVariable String name) {
        return participentService.getAParticipant(name);
    }

    @RequestMapping(method = RequestMethod.POST, value = "/people")
    public void addParticipant(@RequestBody Participant participant){
        participentService.addParticipant(participant);
    }

    @RequestMapping(method = RequestMethod.PUT, value = "/people/{name}")
    public void updateParticipant(@RequestBody Participant participant, @PathVariable String name) {
        participentService.updateParticipant(participant, name);
    }

    @RequestMapping(method = RequestMethod.DELETE, value = "/people/{name}")
    public void deleteParticipant(@PathVariable String name) {
        participentService.deleteParticipant(name);
    }

}

//ParticipantService class

package com.example.spring2.participants;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Arrays;
import java.util.List;

@Service
public class ParticipentService {

    private List<Participant> participantList = Arrays.asList(
        new Participant("yasas", 23, "Student"),
        new Participant("anu", 28, "accountant"),
        new Participant("banu", 26, "teacher")
    );

    @Autowired
    private ParticipantRepository participantRepositoty;


    public List<Participant> getParticipants(){

        return participantList;
    }

    public void addParticipant(Participant participant) {
        participantList.add(participant);

    }

    public void updateParticipant(Participant participant, String name ){
        for (int i=0; i < participantList.size(); i++){
            Participant p = participantList.get(i);
            if (p.getName().equals(name)){
                participantList.set(i, participant);
                return;
            }
        }
    }

    public void deleteParticipant(String name ){
        for (int i=0; i < participantList.size(); i++){
            Participant p = participantList.get(i);
            if (p.getName().equals(name)){
                participantList.remove(p);
            }
        }
    }

    public Participant getAParticipant(String name) {
        for (int i=0; i < participantList.size(); i++){
            Participant p = participantList.get(i);
            if (p.getName().equals(name)){
                return p;
            }
        }
        return  null;
    }
}

//POM.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
        <groupId>com.example</groupId>
        <artifactId>spring2</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>spring2</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.apache.derby</groupId>
            <artifactId>derby</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.0</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

I expected the server to be started when the application is run. But it gives following error.

Description:

An attempt was made to call the method javax.persistence.PersistenceContext.synchronization()Ljavax/persistence/SynchronizationType; but it does not exist. Its class, javax.persistence.PersistenceContext, is available from the following locations:

    jar:file:/C:/Users/Asus/.m2/repository/org/hibernate/javax/persistence/hibernate-jpa-2.0-api/1.0.1.Final/hibernate-jpa-2.0-api-1.0.1.Final.jar!/javax/persistence/PersistenceContext.class
    jar:file:/C:/Users/Asus/.m2/repository/org/hibernate/javax/persistence/hibernate-jpa-2.1-api/1.0.0.Final/hibernate-jpa-2.1-api-1.0.0.Final.jar!/javax/persistence/PersistenceContext.class

It was loaded from the following location:

    file:/C:/Users/Asus/.m2/repository/org/hibernate/javax/persistence/hibernate-jpa-2.0-api/1.0.1.Final/hibernate-jpa-2.0-api-1.0.1.Final.jar

Action:

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

Answer 1

first remove in your repository maven the directory hibernate and then make a maven clean install to reimport correctly your dependencies. if it still doesn't fix your problem make a maven tree:dependency to detect what dependence import the hibernate-jpa-2.0-api and exclude it in your pom

Answer 2

只需检查依赖树从项目依赖列表中的依赖中删除jar

Answer 3

Try going to the location where the dependency is been loaded under the .m2 folder and remove the specific folder hibernate-jpa-2.0-api

Once you remove the folder try doing maven clean install .

Build the project and run it again.

The reason why it occurred because there were two version

hibernate-jpa-2.0-api/ 1.0.0.Final /hibernate-jpa-2.0-api-1.0.1.Final.jar

hibernate-jpa-2.0-api/ 1.0.1.Final /hibernate-jpa-2.0-api-1.0.1.Final.jar

and it should contain only a single, compatible version of javax.persistence.PersistenceContext

Answer 4

There are 4 steps to do that:

1. You must find the location of the dependency that you want to delete, in your I think does you want to remove hibernate-jpa-2.0-api-1.0.1.Final.jar

    mvn dependency:tree

2. When you find the location you must put exclusions on the dependency which load the unwanted dependency such as

   <dependency> ... <exclusions> <exclusion> <groupId>org.hibernate.javax.persistence</groupId> <artifactId>hibernate-jpa-2.0-api</artifactId> <version>1.0.1.Final</version> </exclusion> </exclusions> </dependency>

3. In my case I clean my project such as

   mvn clean

4. You can verify if it's already present mvn dependency:tree | grep hibernate-jpa-2.0-api mvn dependency:tree | grep hibernate-jpa-2.0-api