java - 获取 java.lang.ExceptionInInitializerError

Question

我正在为学校练习创建一个小程序。我不知道我哪里做错了。有人可以帮我解决这个问题吗？

运行测试时出现此错误。我在 this.emf = TestUtil.getEMF(); 行收到错误。

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package herkansing;

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;

@Entity
@NamedQueries({
    @NamedQuery(name = "Account.getAll", query = "select a from Account as a"),
    @NamedQuery(name = "Account.count", query = "select count(a) from Account as a"),
    @NamedQuery(name = "Account.findByAccountNr", query = "select a from Account as a where a.accountNr = :accountNr")
})
public class Player implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long Id;
    private Long accountNr;
    private String email;
    private Long money;
    private Long points;

    public Player() {
    }

    public Player(Long accountNr){
        money = 0L;
        points = 0L;
        this.accountNr = accountNr;
    }

    //<editor-fold defaultstate="collapsed" desc="getters and setters ....">

    public Boolean add(Long amount) {
        if (money + amount >= points) {
            money += amount;
            return true;
        } else {
            return false;
        }
    }

    public Long getId() {
        return Id;
    }

    public void setId(Long id) {
        this.Id = id;
    }

    public Long getAccountNr() {
        return accountNr;
    }

    public void setAccountNr(Long nr) {
        this.accountNr = nr;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Long getMoney() {
        return money;
    }

    public void setMoney(Long money) {
        this.money = money;
    }

    public Long getPoints() {
        return points;
    }

    public void setPoints(Long points) {
        this.points = points;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final Player other = (Player) obj;
        if (this.accountNr != other.accountNr && (this.accountNr == null || !this.accountNr.equals(other.accountNr))) {
            return false;
        }
        if (this.money != other.money && (this.money == null || !this.money.equals(other.money))) {
            return false;
        }
        if (this.points != other.points && (this.points == null || !this.points.equals(other.points))) {
            return false;
        }
        return true;
    }
} 

玩家等级

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
  <persistence-unit name="playerPU" transaction-type="RESOURCE_LOCAL">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <class>herkansing.Player</class>
    <shared-cache-mode>NONE</shared-cache-mode>
    <properties>
      <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/?user=root"/>
      <property name="javax.persistence.jdbc.user" value="root"/>
      <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
      <property name="javax.persistence.jdbc.password" value="root"/>
      <property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
      <!--adds logging-->
      <property name="eclipselink.logging.logger" value="DefaultLogger"/>
      <property name="eclipselink.logging.level" value="FINE"/>
    </properties>
  </persistence-unit>
</persistence>

持久性.xml

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package herkansing;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

/**
 *
 * @author Bart
 */
public class TestUtil {

    static final EntityManagerFactory emf = Persistence.createEntityManagerFactory("playerPU");

    /**
     *
     * @return the number of Accounts stored in the database
     */
    static public int getNrOfAccountRecordsInDB() {
        EntityManager em = getEMF().createEntityManager();
        return ((Number) em.createNamedQuery("Player.count").getSingleResult()).intValue();
    }

    /**
     * Search for an entity of the specified class and primary key.
     *
     * @param id
     * @return the found Account instance or null if the entity does not exist
     */
    static public Player getAccountById(Long id) {
        EntityManager em = getEMF().createEntityManager();
        return em.find(Player.class, id);
    }

    static public EntityManagerFactory getEMF() {
        return emf;
    }

}

TestUtil 类

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package herkansingTest;

import herkansing.TestUtil;
import herkansing.DatabaseCleaner;
import herkansing.Player;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import static org.junit.Assert.*;

/**
 *
 * @author Bart
 */
public class PlayerTest {

    final EntityManagerFactory emf;
    EntityManager em, em1, em2;
    private static final Logger LOG = Logger.getLogger(PlayerTest.class.getName());

    public PlayerTest() {
        this.emf = TestUtil.getEMF();
    }

    @Before
    public void setUp() {
        em = emf.createEntityManager();
        em1 = emf.createEntityManager();
        em2 = emf.createEntityManager();
        new DatabaseCleaner().resetDatabase();
    }
}

玩家测试

java.lang.ExceptionInInitializerError
    at herkansingTest.PlayerTest.<init>(PlayerTest.java:34)
    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:422)
    at org.junit.runners.BlockJUnit4ClassRunner.createTest(BlockJUnit4ClassRunner.java:217)
    at org.junit.runners.BlockJUnit4ClassRunner$1.runReflectiveCall(BlockJUnit4ClassRunner.java:266)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.BlockJUnit4ClassRunner.methodBlock(BlockJUnit4ClassRunner.java:263)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:53)
    at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:123)
    at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:104)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:164)
    at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:110)
    at org.apache.maven.surefire.booter.SurefireStarter.invokeProvider(SurefireStarter.java:175)
    at org.apache.maven.surefire.booter.SurefireStarter.runSuitesInProcessWhenForked(SurefireStarter.java:107)
    at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:68)
Caused by: javax.persistence.PersistenceException: Exception [EclipseLink-28019] (Eclipse Persistence Services - 2.6.0.v20150309-bf26070): org.eclipse.persistence.exceptions.EntityManagerSetupException
Exception Description: Deployment of PersistenceUnit [playerPU] failed. Close all factories for this PersistenceUnit.
Internal Exception: Exception [EclipseLink-0] (Eclipse Persistence Services - 2.6.0.v20150309-bf26070): org.eclipse.persistence.exceptions.JPQLException
Exception Description: Problem compiling [select a from Account as a]. 
[14, 21] The abstract schema type 'Account' is unknown.
    at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.createDeployFailedPersistenceException(EntityManagerSetupImpl.java:866)
    at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:806)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getAbstractSession(EntityManagerFactoryDelegate.java:205)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getDatabaseSession(EntityManagerFactoryDelegate.java:183)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.getDatabaseSession(EntityManagerFactoryImpl.java:528)
    at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactoryImpl(PersistenceProvider.java:146)
    at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:183)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
    at herkansing.TestUtil.<clinit>(TestUtil.java:18)
    ... 31 more
Caused by: Exception [EclipseLink-28019] (Eclipse Persistence Services - 2.6.0.v20150309-bf26070): org.eclipse.persistence.exceptions.EntityManagerSetupException
Exception Description: Deployment of PersistenceUnit [playerPU] failed. Close all factories for this PersistenceUnit.
Internal Exception: Exception [EclipseLink-0] (Eclipse Persistence Services - 2.6.0.v20150309-bf26070): org.eclipse.persistence.exceptions.JPQLException
Exception Description: Problem compiling [select a from Account as a]. 
[14, 21] The abstract schema type 'Account' is unknown.
    at org.eclipse.persistence.exceptions.EntityManagerSetupException.deployFailed(EntityManagerSetupException.java:239)
    ... 41 more
Caused by: Exception [EclipseLink-0] (Eclipse Persistence Services - 2.6.0.v20150309-bf26070): org.eclipse.persistence.exceptions.JPQLException
Exception Description: Problem compiling [select a from Account as a]. 
[14, 21] The abstract schema type 'Account' is unknown.
    at org.eclipse.persistence.internal.jpa.jpql.HermesParser.buildException(HermesParser.java:155)
    at org.eclipse.persistence.internal.jpa.jpql.HermesParser.validate(HermesParser.java:347)
    at org.eclipse.persistence.internal.jpa.jpql.HermesParser.populateQueryImp(HermesParser.java:278)
    at org.eclipse.persistence.internal.jpa.jpql.HermesParser.buildQuery(HermesParser.java:163)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.buildEJBQLDatabaseQuery(EJBQueryImpl.java:142)
    at org.eclipse.persistence.internal.jpa.JPAQuery.processJPQLQuery(JPAQuery.java:223)
    at org.eclipse.persistence.internal.jpa.JPAQuery.prepare(JPAQuery.java:184)
    at org.eclipse.persistence.queries.DatabaseQuery.prepareInternal(DatabaseQuery.java:624)
    at org.eclipse.persistence.internal.sessions.AbstractSession.processJPAQuery(AbstractSession.java:4363)
    at org.eclipse.persistence.internal.sessions.AbstractSession.processJPAQueries(AbstractSession.java:4323)
    at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.initializeDescriptors(DatabaseSessionImpl.java:584)
    at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.postConnectDatasource(DatabaseSessionImpl.java:804)
    at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.loginAndDetectDatasource(DatabaseSessionImpl.java:748)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:253)
    at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:728)
    ... 39 more

堆栈跟踪

Answer 1

您可以在此处的堆栈跟踪中查看原因:

Exception Description: Problem compiling [select a from Account as a]. 
[14, 21] The abstract schema type 'Account' is unknown.

JPA 无法找到 Account 实体，并且无法创建 EntityManagerFactory。

您必须列出 persistence.xml 中的所有实体，就像列出 Player 类一样:

<class>herkansing.Player</class>
<class>herkansing.Account</class>
...

即使您没有在代码中显式使用 Account 实体，也会有一个引用它的命名查询，并且 JPA 会尝试验证此查询并给出异常:

@NamedQueries({
@NamedQuery(name = "Account.getAll", query = "select a from Account as a"),
@NamedQuery(name = "Account.count", query = "select count(a) from Account as a"),
@NamedQuery(name = "Account.findByAccountNr", query = "select a from Account as a where a.accountNr = :accountNr")

})

或者，您可以删除 @NamedQueries 声明。