采用注解方式相对于xml配置的方式就简单多了，那么她和xml配置的方式有什么区别呢。一般一些简单的CURD操作可以选择注解方式来实现，复杂的包括一对多，多对一，调用存储过程的都考虑采用xml配置的方式。
先看一下整个工程的目录结构
001.png
建表语句：
create table users(
id int primary key auto_increment,
name varchar(255),
age int
);
1.首先使用IDEA建一个Maven工程。然后再pom.xml添加如下依赖
<dependencies>
<!-- mysql-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.8</version>
</dependency>
<!-- mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.1</version>
</dependency>
<!-- junit测试包 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
</dependencies>
2.mybatis.xml
<?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>
<!-- 加载类路径下的属性文件 -->
<!--<properties resource="db.properties"/>-->
<!-- 环境配置 -->
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<!-- 数据库连接相关配置 ,这里动态获取config.properties文件中的内容-->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=utf8&useSSL=false" />
<property name="username" value="root" />
<property name="password" value="wscjwacs" />
</dataSource>
</environment>
</environments>
<!-- mapping文件路径配置 -->
<!--<mappers>-->
<!--<mapper resource="mapper/userMapper.xml"/>-->
<!--</mappers>-->
<!-- 在配置文件中 关联包下的 接口类-->
<mappers>
<mapper class="com.flyz.UserMapper"/>
</mappers>
</configuration>
3.UserMapper.java
package com.flyz;
import java.util.List;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
public interface UserMapper {
/*
* 这是基于注解的映射方式，实现对数据的增删改查，将sql语句直接写在注解的括号中
* 这是一个接口，其不需要类去实现它
* 下边分别是插入，删除，修改，查询一个记录，查询所有的记录
* */
@Insert("insert into users(name,age) values(#{name},#{age})")
public void insertT(User user);
@Delete("delete from users where id=#{id}")
public void deleteById(int id);
@Update("update users set name=#{name},age=#{age} where id=#{id}")
public void updateT(User user);
@Select("select * from users where id=#{id}")
public User getUser(int id);
@Select("select * from users")
public List<User> getAllUsers();
}
- User.java
package com.flyz;
public class User {
// 实体类参数最好用包装类型
private Integer id;
private String name;
private Integer age;
public User(Integer id, String name, Integer age) {
this.id = id;
this.name = name;
this.age = age;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
", age=" + age +
'}';
}
}
5.MybatisUtils.java
package com.flyz;
import java.io.InputStream;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class MybatisUtils {
public static SqlSessionFactory getFactory(){
String resource="mybatis.xml";
//加载mybatis 的配置文件（它也加载关联的映射文件）
InputStream is=MybatisUtils.class.getClassLoader().getResourceAsStream(resource);
//构建sqlSession 的工厂
SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(is);
return factory;
}
}
以上是所所有的文件
下面是test测试文件
import com.flyz.MybatisUtils;
import com.flyz.User;
import com.flyz.UserMapper;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.junit.Test;
import java.util.List;
public class UserTest {
@Test
//插入数据
public void testInsert(){
SqlSessionFactory factory= MybatisUtils.getFactory();
SqlSession session=factory.openSession(true);
//使用反射的方法
UserMapper mapper=session.getMapper(UserMapper.class);
mapper.insertT(new User(-1, "p", 4));
mapper.insertT(new User(-1, "Jerry", 20));
session.close();
}
@Test
//删除数据
public void testDelete(){
SqlSessionFactory factory=MybatisUtils.getFactory();
SqlSession session=factory.openSession(true);
UserMapper mapper=session.getMapper(UserMapper.class);
mapper.deleteById(1);
session.close();
}
@Test
//修改数据
public void testUpdate(){
SqlSessionFactory factory=MybatisUtils.getFactory();
SqlSession session=factory.openSession(true);
UserMapper mapper=session.getMapper(UserMapper.class);
mapper.updateT(new User(2, "jjjjj", 232));
session.close();
}
@Test
//获取一条数据
public void testGetUser(){
SqlSessionFactory factory=MybatisUtils.getFactory();
SqlSession session=factory.openSession(true);
UserMapper mapper=session.getMapper(UserMapper.class);
User user=mapper.getUser(2);
session.close();
System.out.println(user);
}
@Test
//获取所有数据
public void testGetAllUsers(){
SqlSessionFactory factory=MybatisUtils.getFactory();
SqlSession session=factory.openSession(true);
UserMapper mapper=session.getMapper(UserMapper.class);
List<User> users=mapper.getAllUsers();
session.close();
System.out.println(users);
}
}
网友评论