1.创建maven工程导入依赖
org.mybatis
mybatis
3.5.9
mysql
mysql-connector-java
5.1.47
junit
junit
4.13.2
test
log4j
log4j
1.2.17
2.在resources中创建db.properties
jdbc.driver = com.mysql.jdbc.Driver
jdbc.url = jdbc:mysql:///mybatis-220301 //自己的数据库
jdbc.user = root //数据库账户
jdbc.password = root //密码
3.创建实体类
public class User {
private Integer id;
private String username;
private String password;
public User() {
}
public User(Integer id, String username, String password) {
this.id = id;
this.username = username;
this.password = password;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + ''' +
", password='" + password + ''' +
'}';
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
4.在mapper文件夹中创建UserMapper类
import com.hqyj.lls.entity.User;
import org.apache.ibatis.annotations.*;
import java.util.List;
public interface UserMapper {
//查所有
@Select("select * from user")
List select();
//根据id 查所有
@Select("select * from user where id = #{id}")
List selectOne(Integer id);
//删除
@Delete("delete from user where id = #{userid}")
Integer delete(int id);
//添加
@Insert("insert into user values (#{id},#{username},#{password})")
Integer insert(User user);
//修改
@Update("update user set username = #{name},password = #{pwd} where id = #{id}")
Integer update(@Param("id") Integer id,@Param("name") String name,@Param("pwd") String pwd);
}
5.新建一个utils工具文件夹，在文件夹中新建一个MybatisUtils工具类来加载mybatis-config.xml文件
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 java.io.IOException;
import java.io.InputStream;
public class MybatisUtils {
private static SqlSessionFactory sqlSessionFactory;
static {
try {
InputStream rs = Resources.getResourceAsStream("mybatis-config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(rs);
} catch (IOException e) {
e.printStackTrace();
}
}
public static SqlSession getSession(){
return sqlSessionFactory.openSession(true);
}
}
6.在resources中创建Mybatis核心配置文件mybatis-config.xml
7.使用测试类测试
import com.hqyj.lls.entity.User;
import com.hqyj.lls.mapper.UserMapper;
import com.hqyj.lls.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.List;
public class TestUser {
private static SqlSession session = MybatisUtils.getSession();
//查所有
@Test
public void select(){
UserMapper mapper = session.getMapper(UserMapper.class);
List select = mapper.select();
for (User user:select){
System.out.println(user);
}
}
//根据id查
@Test
public void selectOne(){
UserMapper mapper = session.getMapper(UserMapper.class);
List users = mapper.selectOne(1);
System.out.println(users);
}
//根据id删除
@Test
public void delete(){
UserMapper mapper = session.getMapper(UserMapper.class);
Integer delete = mapper.delete(3);
System.out.println(delete);
}
//添加
@Test
public void insert(){
UserMapper mapper = session.getMapper(UserMapper.class);
User user = new User(5, "zhaoliu", "789");
Integer insert = mapper.insert(user);
System.out.println(insert);
}
//修改
@Test
public void update(){
UserMapper mapper = session.getMapper(UserMapper.class);
Integer lisi = mapper.update(2, "lisi", "132");
System.out.println(lisi);
}
}
