無法將java.lang.Integer字段ID設置爲org.hibernate.id.IdentifierGeneratorHelper

Question

我需要使用Jpa 2/Hibernate 3.5.1將一些數據存儲在MySQL數據庫中。由於遺留的原因，我想要在其中存儲數據的表具有複合主鍵。主鍵的第一部分是INTEGER（自動遞增值）類型，第二部分是BIGINT類型（Java中的Long - 代碼 - 在持久化之前手動設置）。

我已經實現（棧跟蹤下面的示例代碼）經由@ IdClass-註釋合併的主鍵，第一鍵部分還具有生成策略組：@GeneratedValue（策略= GenerationType.IDENTITY）

當試圖持久化對象的代碼是這樣

... 
TestData testData = new TestData("data"); 
testData.setIdPartTwo(2L); 

entityManager.getTransaction().begin(); 
entityManager.persist(testData); 
entityManager.getTransaction().commit(); 

以下異常被拋出：

javax.persistence.PersistenceException: org.hibernate.PropertyAccessException: could not set a field value by reflection setter of org.example.persistence.TestDataId.idPartOne 
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1235) 
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1168) 
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1174) 
at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:674) 
at org.example.persistence.PersistenceTest.shouldPersistTestData(PersistenceTest.java:45) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
at java.lang.reflect.Method.invoke(Method.java:597) 
at org.testng.internal.MethodHelper.invokeMethod(MethodHelper.java:640) 
at org.testng.internal.Invoker.invokeMethod(Invoker.java:627) 
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:799) 
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1103) 
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:137) 
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:121) 
at org.testng.TestRunner.runWorkers(TestRunner.java:1098) 
at org.testng.TestRunner.privateRun(TestRunner.java:727) 
at org.testng.TestRunner.run(TestRunner.java:581) 
at org.testng.SuiteRunner.runTest(SuiteRunner.java:315) 
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:310) 
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:272) 
at org.testng.SuiteRunner.run(SuiteRunner.java:221) 
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:40) 
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:83) 
at org.testng.internal.thread.ThreadUtil$CountDownLatchedRunnable.run(ThreadUtil.java:151) 
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) 
at java.lang.Thread.run(Thread.java:619) 


Caused by: org.hibernate.PropertyAccessException: could not set a field value by reflection setter of org.example.persistence.TestDataId.idPartOne 
at org.hibernate.property.DirectPropertyAccessor$DirectSetter.set(DirectPropertyAccessor.java:151) 
at org.hibernate.mapping.Component$ValueGenerationPlan.execute(Component.java:438) 
at org.hibernate.id.CompositeNestedGeneratedValueGenerator.generate(CompositeNestedGeneratedValueGenerator.java:122) 
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:122) 
at org.hibernate.ejb.event.EJB3PersistEventListener.saveWithGeneratedId(EJB3PersistEventListener.java:69) 
at org.hibernate.event.def.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:179) 
at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:135) 
at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:61) 
at org.hibernate.impl.SessionImpl.firePersist(SessionImpl.java:800) 
at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:774) 
at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:778) 
at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:668) 
... 24 more 


Caused by: java.lang.IllegalArgumentException: Can not set java.lang.Integer field org.example.persistence.TestDataId.idPartOne to org.hibernate.id.IdentifierGeneratorHelper$2 
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:146) 
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:150) 
at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:63) 
at java.lang.reflect.Field.set(Field.java:657) 
at org.hibernate.property.DirectPropertyAccessor$DirectSetter.set(DirectPropertyAccessor.java:139) 
... 35 more 

我的實體類看起來升IKE在此：

@Entity 
@IdClass(TestDataId.class) 
public class TestData implements Serializable { 
    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    private Integer idPartOne; 
    @Id 
    private Long idPartTwo; 
    private String data; 
    public TestData() {} 
    // getters and setters 
    // hashCode() and equals() 
} 

的聯合主鍵：

CREATE TABLE `testdb`.`testdata` 
(`idPartOne` INTEGER NOT NULL AUTO_INCREMENT, 
`idPartTwo` BIGINT(20) NOT NULL DEFAULT 0, 
`data` VARCHAR(45), 
PRIMARY KEY(`idPartOne`, `idPartTwo`)) 
ENGINE = InnoDB; 

改變GenerationType以表將使其工作：

public class TestDataId implements Serializable { 

    private static final long serialVersionUID = 1L; 
    private Integer idPartOne; 
    private Long idPartTwo; 
    public TestDataId() {} 
    // getters and setters 
    // hashCode() and equals() 
} 

測試，表是用下面的語句創建，但會以〜32.000的步長生成idPartOne值。不幸的是，另一個應用程序在沒有JPA/Hibernate的情況下使用這個非常相同的數據庫表，並且很好地遞增了這個id部分，步長爲1.

無論哪個應用程序，都需要以同樣的方式完成id生成將數據存儲到此表中（即id增加1）。什麼是實現這一目標的最佳解決方案？提示，我們不能改變其他應用程序！

任何幫助真的很感激。

THX，

馬庫斯

Answer 1

是否當你註釋嵌入式ID工作？

@Embeddable 
public class TestDataId 
{ 
    @GeneratedValue(strategy = GenerationType.TABLE) 
    private Integer idPartOne; 
    private Long idPartTwo; 
} 

@Entity 
public class TestData 
{ 
    @EmbeddedId 
    private TestDataId key; 
    private String data; 
}