【发布时间】：2016-10-09 23:17:39
【问题描述】：
我有两个简单的表file 和row，它们是多对多相关的。一个文件可以包含多行，一行可以在多个文件中。
CREATE TABLE file
(
id INT(11) PRIMARY KEY NOT NULL AUTO_INCREMENT,
name VARCHAR(30) DEFAULT '' NOT NULL
);
CREATE UNIQUE INDEX file_id_uindex ON file (id);
CREATE TABLE row
(
id BINARY(16) PRIMARY KEY NOT NULL,
content TEXT
);
CREATE UNIQUE INDEX row_id_uindex ON row (id);
CREATE TABLE file_row
(
file_id INT(11),
row_id BINARY(16),
CONSTRAINT file_id___fk FOREIGN KEY (file_id) REFERENCES file (id),
CONSTRAINT row_id___fk FOREIGN KEY (row_id) REFERENCES row (id)
);
CREATE INDEX file_id___fk ON file_row (file_id);
CREATE INDEX row_id___fk ON file_row (row_id);
由于row.id我使用行内容的哈希，所以在表中只能存储唯一的行。
还有我在 java 中的映射类：
@Getter
@Setter
@Entity
@Table(name = "file")
public class File implements Serializable {
@Builder
public File(int id, String name, List<Row> rows) {
this.id = id;
this.name =name;
this.rows = rows;
}
public File(){
}
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
@Column(name = "name")
private String name;
@ManyToMany(cascade = CascadeType.MERGE)
@JoinTable(name = "file_row",
joinColumns = @JoinColumn(name = "file_id"),
inverseJoinColumns = @JoinColumn(name = "row_id"))
private List<Row> rows;
}
@Getter
@Setter
@Entity
@Table(name = "row")
public class Row implements Serializable{
public Row() {
}
@Builder
public Row(byte[] id, String content, List<File> files){
this.id = id;
this.content = content;
this.files = files;
}
@Id
@Column(columnDefinition = "BINARY(16)")
private byte[] id;
@Lob
@Column(name = "content")
private String content;
@ManyToMany(mappedBy = "rows", cascade = CascadeType.MERGE)
private List<File> files;
}
为了保存实体，我使用EntityManager 类的persist() 方法。
当我添加具有唯一行的新文件时 - 一切都很好。但是，如果我尝试使用重复行保存文件，则会发生错误：
Caused by: javax.persistence.EntityExistsException: A different object with the same identifier value was already associated with the session : [com.restapp.entity.Row#[B@183c1f56]
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1664)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1602)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1608)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:1152)
at org.jboss.as.jpa.container.AbstractEntityManager.persist(AbstractEntityManager.java:580)
at com.restapp.dao.AbstractDao.persist(AbstractDao.java:43)
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:498)
at org.jboss.as.ee.component.ManagedReferenceMethodInterceptor.processInvocation(ManagedReferenceMethodInterceptor.java:52)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:437)
at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.doMethodInterception(Jsr299BindingsInterceptor.java:82)
at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.processInvocation(Jsr299BindingsInterceptor.java:93)
at org.jboss.as.ee.component.interceptors.UserInterceptorFactory$1.processInvocation(UserInterceptorFactory.java:63)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.component.invocationmetrics.ExecutionTimeInterceptor.processInvocation(ExecutionTimeInterceptor.java:43)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.jpa.interceptor.SBInvocationInterceptor.processInvocation(SBInvocationInterceptor.java:47)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:437)
at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:64)
at org.jboss.as.weld.ejb.EjbRequestScopeActivationInterceptor.processInvocation(EjbRequestScopeActivationInterceptor.java:83)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ee.concurrent.ConcurrentContextInterceptor.processInvocation(ConcurrentContextInterceptor.java:45)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.InitialInterceptor.processInvocation(InitialInterceptor.java:21)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
at org.jboss.as.ee.component.interceptors.ComponentDispatcherInterceptor.processInvocation(ComponentDispatcherInterceptor.java:52)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.component.pool.PooledInstanceInterceptor.processInvocation(PooledInstanceInterceptor.java:51)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInCallerTx(CMTTxInterceptor.java:254)
... 178 more
当我使用表中已经存在的行保存文件时也会发生错误。
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '\xE6t\xDB]\xFA\xF0\xAFz\xD4\xED\xAE\xFC\x84\xD7\x99\xA9' for key 'PRIMARY'
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 com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:935)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3970)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3906)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2524)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2677)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2549)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1861)
at com.mysql.jdbc.PreparedStatement.executeUpdateInternal(PreparedStatement.java:2073)
at com.mysql.jdbc.PreparedStatement.executeUpdateInternal(PreparedStatement.java:2009)
at com.mysql.jdbc.PreparedStatement.executeLargeUpdate(PreparedStatement.java:5098)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1994)
at org.jboss.jca.adapters.jdbc.WrappedPreparedStatement.executeUpdate(WrappedPreparedStatement.java:537)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:204)
... 129 more
请帮我解决我的问题。
【问题讨论】：
标签： java mysql jpa-2.0 java-ee-7