@MappedSuperclass的用法

来源：互联网发布：怎么做网络覆盖编辑：程序博客网时间：2024/05/20 04:10

实体类baseEntity.java

package com.rock.cft.hibernate;
import java.util.Date;
import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.MappedSuperclass;
//@MappedSuperclass 用在父类上面。当这个类肯定是父类时，加此标注。如果改成@Entity，则继承后，多个类继承，只会生成一个表，而不是多个继承，生成多个表@MappedSuperclasspublic abstract class BaseEntity {  private Integer id;// 数据库主键 private Date creationTime;//创建时间 private Date modificationTime;//修改时间  @Id @GeneratedValue(strategy = GenerationType.AUTO) public Integer getId() {  return id; } public void setId(Integer id) {  this.id = id; } public Date getCreationTime() {  return creationTime; } public void setCreationTime(Date creationTime) {  this.creationTime = creationTime; } public Date getModificationTime() {  return modificationTime; } public void setModificationTime(Date modificationTime) {  this.modificationTime = modificationTime; }
 }

实体类Test_No1.java package com.rock.cft.test.model;
import java.io.Serializable;import java.util.Date;
import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.Table;
import com.rock.cft.hibernate.BaseEntity;
@Entity@Table(name="test_no2")public class Test_No1 extends BaseEntity implements Serializable {  private String name; private int age;
 
 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; }  
}
实体类Test_NO2.javapackage com.rock.cft.test.model;
import java.io.Serializable;import java.util.Date;
import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.Table;
import com.rock.cft.hibernate.BaseEntity;
@Entity@Table(name="test_no2")public class Test_NO2 extends BaseEntity implements Serializable {   private Date testBri;  private String testAdr;  public Date getTestBri() {  return testBri; } public void setTestBri(Date testBri) {  this.testBri = testBri; } public String getTestAdr() {  return testAdr; } public void setTestAdr(String testAdr) {  this.testAdr = testAdr; }  
  
} 
 
这样在生成表的时候只生成了：test_no1、test_no2两张表，而且两张表中都含有id、creationTime、modificationTime三个属性
 
但是如果把@MappedSuperclass换成@Entity那么就会另外在生成一张baseEntity的表

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