时间：2021-07-01 10:21:17 帮助过：18人阅读
写在这个系列前面的话: 以前曾经用过ibatis,这是mybatis的前身，当时在做项目时，感觉很不错，比hibernate灵活。性能也比hibernate好。而且也比较轻量级，因为当时在项目中，没来的及做很很多笔记。后来项目结束了，我也没写总结文档。已经过去好久了。但最
写在这个系列前面的话:
以前曾经用过ibatis,这是mybatis的前身，当时在做项目时，感觉很不错，比hibernate灵活。性能也比hibernate好。而且也比较轻量级，因为当时在项目中，没来的及做很很多笔记。后来项目结束了，我也没写总结文档。已经过去好久了。但最近突然又对这个ORM 工具感兴趣。因为接下来自己的项目中很有可能采用这个ORM工具。所以在此重新温习了一下 mybatis, 因此就有了这个系列的 mybatis 教程.5. 在java 对象和 数据库之间有做mapping 的配置文件，也通常是xml 文件。
程序代码
程序代码< ?xml version="1.0" encoding="UTF-8" ?> < !DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> < configuration>< /configuration>
程序代码
package com.yihaomen.mybatis.model;
public class User {
private int id;
private String userName;
private String userAge;
private String userAddress;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getUserAge() {
return userAge;
}
public void setUserAge(String userAge) {
this.userAge = userAge;
}
public String getUserAddress() {
return userAddress;
}
public void setUserAddress(String userAddress) {
this.userAddress = userAddress;
}
}
程序代码< ?xml version="1.0" encoding="UTF-8" ?> < !DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> < mapper namespace="com.yihaomen.mybatis.models.UserMapper"> < /mapper>
程序代码
package com.yihaomen.test;
import java.io.Reader;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import com.yihaomen.mybatis.model.User;
public class Test {
private static SqlSessionFactory sqlSessionFactory;
private static Reader reader;
static{
try{
reader = Resources.getResourceAsReader("Configuration.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
}catch(Exception e){
e.printStackTrace();
}
}
public static SqlSessionFactory getSession(){
return sqlSessionFactory;
}
public static void main(String[] args) {
SqlSession session = sqlSessionFactory.openSession();
try {
User user = (User) session.selectOne("com.yihaomen.mybatis.models.UserMapper.selectUserByID", 1);
System.out.println(user.getUserAddress());
System.out.println(user.getUserName());
} finally {
session.close();
}
}
}
程序代码
package com.yihaomen.mybatis.inter;
import com.yihaomen.mybatis.model.User;
public interface IUserOperation {
public User selectUserByID(int id);
}
程序代码
public static void main(String[] args) {
SqlSession session = sqlSessionFactory.openSession();
try {
IUserOperation userOperation=session.getMapper(IUserOperation.class);
User user = userOperation.selectUserByID(1);
System.out.println(user.getUserAddress());
System.out.println(user.getUserName());
} finally {
session.close();
}
}
程序代码< !-- 为了返回list 类型而定义的returnMap -->
程序代码< !-- 返回list 的select 语句，注意 resultMap 的值是指向前面定义好的 -->
程序代码
public void getUserList(String userName){
SqlSession session = sqlSessionFactory.openSession();
try {
IUserOperation userOperation=session.getMapper(IUserOperation.class);
List users = userOperation.selectUsers(userName);
for(User user:users){
System.out.println(user.getId()+":"+user.getUserName()+":"+user.getUserAddress());
}
} finally {
session.close();
}
}
程序代码
public static void main(String[] args) {
Test testUser=new Test();
testUser.getUserList("%");
}
程序代码
< !--执行增加操作的SQL语句。id和parameterType分别与IUserOperation接口中的addUser方法的名字和参数类型一致。以#{name}的形式引用Student参数的name属性，MyBatis将使用反射读取Student参数的此属性。#{name}中name大小写敏感。引用其他的gender等属性与此一致。seGeneratedKeys设置为"true"表明要MyBatis获取由数据库自动生成的主键；keyProperty="id"指定把获取到的主键值注入到Student的id属性-->
insert into user(userName,userAge,userAddress)
values(#{userName},#{userAge},#{userAddress})
程序代码
*/
public void addUser(){
User user=new User();
user.setUserAddress("人民广场");
user.setUserName("飞鸟");
user.setUserAge(80);
SqlSession session = sqlSessionFactory.openSession();
try {
IUserOperation userOperation=session.getMapper(IUserOperation.class);
userOperation.addUser(user);
session.commit();
System.out.println("当前增加的用户 id为:"+user.getId());
} finally {
session.close();
}
}
程序代码update user set userName=#{userName},userAge=#{userAge},userAddress=#{userAddress} where id=#{id}
程序代码
public void updateUser(){
//先得到用户,然后修改，提交。
SqlSession session = sqlSessionFactory.openSession();
try {
IUserOperation userOperation=session.getMapper(IUserOperation.class);
User user = userOperation.selectUserByID(4);
user.setUserAddress("原来是魔都的浦东创新园区");
userOperation.updateUser(user);
session.commit();
} finally {
session.close();
}
}
程序代码delete from user where id=#{id}
程序代码
* @param id
*/
public void deleteUser(int id){
SqlSession session = sqlSessionFactory.openSession();
try {
IUserOperation userOperation=session.getMapper(IUserOperation.class);
userOperation.deleteUser(id);
session.commit();
} finally {
session.close();
}
}
程序代码
Drop TABLE IF EXISTS `article`;
Create TABLE `article` (
`id` int(11) NOT NULL auto_increment,
`userid` int(11) NOT NULL,
`title` varchar(100) NOT NULL,
`content` text NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;
-- ----------------------------
-- 添加几条测试数据
-- ----------------------------
Insert INTO `article` VALUES ('1', '1', 'test_title', 'test_content');
Insert INTO `article` VALUES ('2', '1', 'test_title_2', 'test_content_2');
Insert INTO `article` VALUES ('3', '1', 'test_title_3', 'test_content_3');
Insert INTO `article` VALUES ('4', '1', 'test_title_4', 'test_content_4');
程序代码
package com.yihaomen.mybatis.model;
public class Article {
private int id;
private User user;
private String title;
private String content;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
}
程序代码< !-- User 联合文章进行查询 方法之一的配置 (多对一的方式) -->< select id="getUserArticles" parameterType="int" resultMap="resultUserArticleList"> select user.id,user.userName,user.userAddress,article.id aid,article.title,article.content from user,article where user.id=article.userid and user.id=#{id}
程序代码 程序代码
public void getUserArticles(int userid){
SqlSession session = sqlSessionFactory.openSession();
try {
IUserOperation userOperation=session.getMapper(IUserOperation.class);
List articles = userOperation.getUserArticles(userid);
for(Article article:articles){
System.out.println(article.getTitle()+":"+article.getContent()+
":作者是:"+article.getUser().getUserName()+":地址:"+
article.getUser().getUserAddress());
}
} finally {
session.close();
}
}
程序代码< !--本示例采用DBCP连接池，应预先把DBCP的jar包复制到工程的lib目录下。 -->
程序代码
package com.yihaomen.test;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.yihaomen.mybatis.inter.IUserOperation;
import com.yihaomen.mybatis.model.Article;
import com.yihaomen.mybatis.model.User;
public class MybatisSprintTest {
private static ApplicationContext ctx;
static
{
ctx = new ClassPathXmlApplicationContext("config/applicationContext.xml");
}
public static void main(String[] args)
{
IUserOperation mapper = (IUserOperation)ctx.getBean("userMapper");
//测试id=1的用户查询，根据数据库中的情况，可以改成你自己的.
System.out.println("得到用户id=1的用户信息");
User user = mapper.selectUserByID(1);
System.out.println(user.getUserAddress());
//得到文章列表测试
System.out.println("得到用户id为1的所有文章列表");
List articles = mapper.getUserArticles(1);
for(Article article:articles){
System.out.println(article.getContent()+"--"+article.getTitle());
}
}
}
程序代码contextConfigLocation classpath*:config/applicationContext.xml org.springframework.web.context.ContextLoaderListener org.springframework.web.context.ContextCleanupListener mvc-dispatcher org.springframework.web.servlet.DispatcherServlet 1 mvc-dispatcher /
程序代码
