BaseEntity实体的继承（@MappedSuperclass） _Entity

【BaseEntity实体的继承（@MappedSuperclass）】博观而约取，厚积而薄发。这篇文章主要讲述BaseEntity实体的继承：@MappedSuperclass相关的知识，希望能为你提供帮助。
阅读更多在创建实体时，经常有重复的id和时间的属性要创建，所以想弄一个父类，然后所有实体继承，但是碰到了问题，就用到了@MappedSuperclass，它的的用法
用在实体的继承过程中的父类上；
如：
IdEntity.java
Java代码

文章图片

package com.zpf.test.Entity;
import java.io.Serializable;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.MappedSuperclass;
/**
* 基础实体类
*
* @author zpf
*
*/
@MappedSuperclass
public class IdEntity implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;
@Column(updatable = false)
private Date createDate;
private Date modifyDate;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public Date getCreateDate() {
return createDate;
}
public void setCreateDate(Date createDate) {
this.createDate = createDate;
}
public Date getModifyDate() {
return modifyDate;
}
public void setModifyDate(Date modifyDate) {
this.modifyDate = modifyDate;
}
}

package com.zpf.test.Entity; import java.io.Serializable; import java.util.Date; import javax.persistence.Column; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.MappedSuperclass; /** * 基础实体类 * * @author zpf * */ @MappedSuperclass public class IdEntity implements Serializable {/** * */ private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.AUTO) private long id; @Column(updatable = false) private Date createDate; private Date modifyDate; public long getId() { return id; }public void setId(long id) { this.id = id; }public Date getCreateDate() { return createDate; }public void setCreateDate(Date createDate) { this.createDate = createDate; }public Date getModifyDate() { return modifyDate; }public void setModifyDate(Date modifyDate) { this.modifyDate = modifyDate; }}

Java代码

文章图片

package com.zpf.test.Entity;
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.Table;
/**
* 用户实体
* @author zpf
*
*/
@Entity
@Table(name="tb_user")
public class User extends IdEntity implements Serializable{
private static final long serialVersionUID = 1L;
private String name;
private String sex;
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}

package com.zpf.test.Entity; import java.io.Serializable; import javax.persistence.Entity; import javax.persistence.Table; /** * 用户实体 * @author zpf * */ @Entity @Table(name="tb_user") public class User extends IdEntity implements Serializable{private static final long serialVersionUID = 1L; private String name; private String sex; private int age; public String getName() { return name; }public void setName(String name) { this.name = name; }public String getSex() { return sex; }public void setSex(String sex) { this.sex = sex; }public int getAge() { return age; }public void setAge(int age) { this.age = age; }}

这样就会生成tb_user表而且包含父类属性，否则只会生成一张identity表，字段有：id，crearedate,modifydate,name，sex，age 原文地址：https://www.iteye.com/blog/peng13123-2062980