什么是 MyBatis？
MyBatis 是支持普通 SQL 查询，存储过程和高级映射的优秀持久层框架。 MyBatis 消除了几乎所有的 JDBC 代码和参数的手工设置以及对结果集的检索。MyBatis 可以使用简单的XML 或注解用于配置和原始映射，将接口和 Java 的 POJO（Plain Old Java Objects，普通的Java对象）映射成数据库中的记录。
MyBatis下载：https://github.com/mybatis/mybatis-3/releases
Mybatis实例
对一个User表的CRUD操作：
User表：
-- ----------------------------
-- Table structure for `user`
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`userName` varchar(50) DEFAULT NULL,
`userAge` int(11) DEFAULT NULL,
`userAddress` varchar(200) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES ('1', 'summer', '30', 'shanghai');
INSERT INTO `user` VALUES ('2', 'test2', '22', 'suzhou');
INSERT INTO `user` VALUES ('3', 'test1', '29', 'some place');
INSERT INTO `user` VALUES ('4', 'lu', '28', 'some place');
INSERT INTO `user` VALUES ('5', 'xiaoxun', '27', 'nanjing');
在Src目录下建一个mybatis的xml配置文件Configuration.xml
定义User mappers的User.xml配置文件
insert into user(userName,userAge,userAddress) values(#{userName},#{userAge},#{userAddress}) update user set userName=#{userName},userAge=#{userAge},userAddress=#{userAddress} where id=#{id} delete from user where id=#{id}
配置文件实现了接口和SQL语句的映射关系。selectUsersByName采用了2种方式实现，注释掉的也是一种实现，采用resultMap可以把属性和数据库列名映射关系定义好，property为类的属性，column是表的列名，也可以是表列名的别名！
User类的定义：
package com.mybatis.test;
public class User {
private int id;
private String userName;
private int 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 int getUserAge() {
return userAge;
}
public void setUserAge(int userAge) {
this.userAge = userAge;
}
public String getUserAddress() {
return userAddress;
}
public void setUserAddress(String userAddress) {
this.userAddress = userAddress;
}
@Override
public String toString(){
return this.userName+" "+this.userAge+" "+this.userAddress;
}
}
IUserOperaton定义：
package com.mybatis.test;
import java.util.List;
public interface IUserOperation {
public User selectUserByID(int id);
public List selectUsersByName(String userName);
public void addUser(User user);
public void updateUser(User user);
public void deleteUser(int id);
}
IUserOperation为操作接口，函数名和mybatis的xml配置文件中的操作id名对应。
测试类Test：
package com.mybatis.test;
import java.io.Reader;
import java.util.List;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
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 void getUserByID(int userID) {
SqlSession session = sqlSessionFactory.openSession();
try {
IUserOperation userOperation = session
.getMapper(IUserOperation.class);
User user = userOperation.selectUserByID(userID);
if (user != null) {
System.out.println(user.getId() + ":" + user.getUserName()
+ ":" + user.getUserAddress());
}
} finally {
session.close();
}
}
public void getUserList(String userName) {
SqlSession session = sqlSessionFactory.openSession();
try {
IUserOperation userOperation = session
.getMapper(IUserOperation.class);
List users = userOperation.selectUsersByName(userName);
for (User user : users) {
System.out.println(user.getId() + ":" + user.getUserName()
+ ":" + user.getUserAddress());
}
} finally {
session.close();
}
}
/**
* 增加后要commit
*/
public void addUser() {
User user = new User();
user.setUserAddress("place");
user.setUserName("test_add");
user.setUserAge(30);
SqlSession session = sqlSessionFactory.openSession();
try {
IUserOperation userOperation = session
.getMapper(IUserOperation.class);
userOperation.addUser(user);
session.commit();
System.out.println("新增用户ID：" + user.getId());
} finally {
session.close();
}
}
/**
* 修改后要commit
*/
public void updateUser() {
SqlSession session = sqlSessionFactory.openSession();
try {
IUserOperation userOperation = session
.getMapper(IUserOperation.class);
User user = userOperation.selectUserByID(1);
if (user != null) {
user.setUserAddress("A new place");
userOperation.updateUser(user);
session.commit();
}
} finally {
session.close();
}
}
/**
* 删除后要commit.
*
* @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();
}
}
public static void main(String[] args) {
try {
Test test = new Test();
// test.getUserByID(1);
// test.getUserList("test1");
// test.addUser();
// test.updateUser();
// test.deleteUser(6);
} catch (Exception e) {
System.out.println(e.getMessage());
}
}
}
原文相关地址：
代码下载：http://download.csdn.net/detail/luxiaoxun/8056559
Source Code：https://github.com/luxiaoxun/MybatisDemo
参考：
MyBatis-3-User-Guide-zh
http://legend2011.blog.51cto.com/3018495/d-5
http://mybatis.github.io/mybatis-3/zh/sqlmap-xml.html
作者： 阿凡卢
出处： http://www.cnblogs.com/luxiaoxun/