hibernate中联合主键的生成策略

下面是定义组合主键的几种语法:

将组件类注解为@Embeddable,并将组件的属性注解为@Id（不常用）
将组件的属性注解为@EmbeddedId
将类注解为@IdClass,并将该实体中所有属于主键的属性都注解为@Id（个人喜欢这种和第二种）

package wife;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.IdClass;

@Entity
@IdClass(value=Wife_pk.class)
public class Wife {

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

public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
@Id
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;
}
}

这种方法需要主键类一般主键类命名方式采用..._pk
下面有个主键类的例子，注意：主键类一定要实现serializable接口

package wife;

import java.io.Serializable;

public class Wife_pk implements Serializable{

private int id;
private String name;

public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public int hashCode() {
// TODO Auto-generated method stub
return super.hashCode();
}
@Override
public boolean equals(Object obj) {
// TODO Auto-generated method stub
return super.equals(obj);
}

}