hibernate One2Many级联增删改查

最新推荐文章于 2018-12-04 20:03:00 发布

david_yellow

最新推荐文章于 2018-12-04 20:03:00 发布

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本文链接：https://blog.youkuaiyun.com/tarenahuangdw/article/details/50441527

这篇博客详细介绍了在Hibernate框架下如何处理One2Many的级联操作，包括增删改查。通过实例展示了实体对象User的设置，并提供了相关的测试代码。

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环境：maven普通项目

项目结构

1 pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.mycompany</groupId>
  <artifactId>learHibernate</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
  <dependencies>
     <dependency>
		<groupId>org.hibernate</groupId>
		<artifactId>hibernate-core</artifactId>
		<version>4.3.8.Final</version>
    </dependency>
    
	   <dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
		<version>5.1.8</version>
	</dependency>

	
	<dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

2 hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
		"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
		"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.password">huangdawei123</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="hibernate.hbm2ddl.auto">update</property>
        <property name="hibernate.show_sql">true</property>
        
        <mapping class="com.mycompany.beans.User"/>
        <mapping class="com.mycompany.beans.Role"/>
    </session-factory>
</hibernate-configuration>

3 log4j.propertites

log4j.rootLogger = DEBUG , stdout , D
#log4j.logger.org.mybatis=DEBUG 
 
###  output to the console ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = %d{ABSOLUTE} %5p %c{ 1 }:%L - %m%n
log4j.appender.stdout.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [%c]-[%p] %m%n

4 实体对象建立
4.1 User

package com.mycompany.beans;

import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;
import javax.persistence.Table;



@Entity
@Table(name="user")
public class User {
	
	@Id
	@GeneratedValue(strategy=GenerationType.IDENTITY)
	private int userId;
	
	@Column
	private String userName;
	
	@Column
	private String userPwd;
	
	@OneToMany(cascade=CascadeType.ALL, fetch = FetchType.LAZY, targetEntity=Role.class, orphanRemoval=true)
	@JoinColumn(name="userId")
	private Set<Role> roles;
	
	public User(String string, String string2) {
		this.userName = string;
		this.userPwd  = string2;
	}
	
	
	
	public User() {
	}


	public int getUserId() {
		return userId;
	}
	public void setUserId(int userId) {
		this.userId = userId;
	}
	public String getUserName() {
		return userName;
	}
	public void setUserName(String userName) {
		this.userName = userName;
	}
	public String getUserPwd() {
		return userPwd;
	}
	public void setUserPwd(String userPwd) {
		this.userPwd = userPwd;
	}



	public Set<Role> getRoles() {
		return roles;
	}



	public void setRoles(Set<Role> roles) {
		this.roles = roles;
	}
	
	
	
}

4.2

package com.mycompany.beans;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;


@Entity
@Table(name="role")
public class Role {
	@Id
	@GeneratedValue(strategy=GenerationType.IDENTITY)
	private int roleId;
	@Column
	private String roleName;
	
	public int getRoleId() {
		return roleId;
	}
	public void setRoleId(int roleId) {
		this.roleId = roleId;
	}
	public String getRoleName() {
		return roleName;
	}
	public void setRoleName(String roleName) {
		this.roleName = roleName;
	}
	
	
	
}

5 测试代码：

package com.mycompany.test;


import java.util.HashSet;
import java.util.Set;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.junit.Test;

import com.mycompany.beans.Role;
import com.mycompany.beans.User;


public class Hibernate4Test {
//	@Test 简单用户添加
	public void test(){
		 SessionFactory sessionFactory = new Configuration()
          .configure() // configures settings from hibernate.cfg.xml
          .buildSessionFactory(null);
		
		 Session session = sessionFactory.openSession();
		 session.beginTransaction();
		 
		 session.save(CreateUser("账号","密码"));
		 session.save(CreateUser("zhanghao","mima"));
		 session.getTransaction().commit();
		 session.close();
	}

	private User CreateUser(String string, String string2) {
		return new User(string, string2);
	}
	
	//级联增加
	//@Test
	public void cascadeAdd(){
		
		Role role = new Role();
		role.setRoleName("程序员");
		
		Role role2 = new Role();
		role2.setRoleName("程序员");
		
		Set<Role> roles = new  HashSet<Role>();
		roles.add(role);
		roles.add(role2);
		
		User user1 =  this.CreateUser("吉林1", "密码1");
		user1.setRoles(roles);
		
		
		Session session = getSession();
		 session.beginTransaction();
		 session.save(user1);
		 session.getTransaction().commit();
		session.close();
		
	}
	
	
	//级联查询
//	@Test
	public void cascadeQuery(){
		Session session = getSession();
		 session.beginTransaction();
		 User user = (User) session.get(User.class, 1);
		 System.out.println(user.getUserName());
		 Set<Role> roles = user.getRoles();
		 for(Role r : roles){
			 System.out.print(r.getRoleName() + ", ");
		 }
		 session.getTransaction().commit();
		session.close();
	}
	
	//级联修改
//	@Test
	public void cascadeUpdate(){
		Session session = getSession();
		 session.beginTransaction();
		 User user = (User) session.get(User.class, 1);
		 System.out.println(user.getUserName());
		 Set<Role> roles = user.getRoles();
		 int i = 0;
		 for(Role r : roles){
			 i++;
//			 System.out.print(r.getRoleName() + ", ");
			 r.setRoleName(user.getUserName()+":"+r.getRoleName() + i);
		 }
		 session.getTransaction().commit();
		session.close();
		
		
//		cascadeQuery();
	}
	
	//级联删除
//	@Test
	public void cascadeDelete(){
		 Session session = getSession();
		 session.beginTransaction();
		 User user = (User) session.get(User.class, 2);
//		 System.out.println(user.getUserName());
//		 Set<Role> roles = user.getRoles();
//		 for(Role r : roles){
//			 System.out.print(r.getRoleName() + ", ");
//		 }

		 session.delete(user);
		 
		session.getTransaction().commit();
		session.close();
		
//		cascadeQuery();
	}

	private Session getSession() {
		return new Configuration().configure().buildSessionFactory().openSession();
	}
	
	
	
	
}