如何通过XML方式配置并实现Mybatis

idea中创建一个maven项目

在pom文件中导入下面的依赖

  
   org.mybatis
   mybatis
   3.4.6
  
  
  
   mysql
   mysql-connector-java
   8.0.18
  
  
  
   log4j
   log4j
   1.2.17
  

创建一个java源文件夹和resources资源文件夹并准备好mybatis配置文件mybaits.xml和数据库文件db.properties

mybaits.xml

db.properties

driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/prc?userUnicode=true&characterEncoding=utf8&serverTimezone=UTC
username=root
password=root

数据库准备

准备相应的对象

创建一个Student对象，和数据库的表对应

public class Student {
  private String s_id;
  private String s_name;
  private String s_birth;
  private String s_sex;

  public Student() {}
  
  //getter,setter 方法省略
｝

mapper的准备 ，创建一个mapper文件夹，并在内创建一个StudentMapper接口

public interface StudentMapper {
	//查找学生表全部信息
  public List selectAll();
	//根据姓名查找学生
  public Student selectByName(String name);
	//插入一条学生信息
  public void insertOne(Student stu);
	//根据姓名删除一条学生信息
  public void deleteByName(String name);
	//根据姓名修改一条学生信息
  public void updateByName(Student stu);

}

在resoures资源文件夹下创建和mapper文件夹路径相同的文件夹

然后创建映射文件StudentMapper.xml

  
  
    SELECT s_id,s_name,s_birth,s_sex FROM student
  
  
  
    SELECT s_id,s_name,s_birth,s_sex FROM student
    WHERE s_name = #{name}
  

  
    INSERT INTO student (s_id,s_name,s_birth,s_sex) VALUES (#{s_id},#{s_name},#{s_birth},#{s_sex})
  

  
    DELETE FROM student where s_name = #{s_name}
  

  
    UPDATE student SET s_birth = #{s_birth},s_sex = #{s_sex} WHERE s_name = #{s_name}
  

抽取出一个MybatisUtil工具类

public class MybatisUtil {
  private static SqlSessionFactory sqlSessionFactory;
	//静态代码块：在使用的时候先执行，并且执行一次
  static {
    try {
      InputStream is = Resources.getResourceAsStream("mybatis.xml");
      SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
      //创建一个工厂实例（加载了我们的配置文件）
      sqlSessionFactory = builder.build(is);
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
	/**
	 *拿到了一个SqlSession对象
	 */
  public static SqlSession getSqlSession() {
    return sqlSessionFactory.openSession();
  }

  public static void closeSqlSession(SqlSession sqlSession) {
    if (sqlSession != null) {
      sqlSession.close();
    }
  }
}

编写测试类

public class SqlTest {
  @Test
  public void testSelectAll() {
    //通过工具类获得SqlSession对象
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    //获取到绑定到SqlSession的POJO类对应的映射
    StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
    //通过映射调用查询方法
    List students = studentMapper.selectAll();
    //关闭SqlSession
    sqlSession.close();
    for (Student student : students) {
      System.out.println(student);
    }
  }

  @Test
  public void testSelectByName() {
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
    Student stu = studentMapper.selectByName("吴兰");
    sqlSession.close();
    System.out.println(stu);
  }

  @Test
  public void testInsertOne() {
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
    Student stu = new Student();
    stu.setS_id("09");
    stu.setS_name("李水");
    stu.setS_birth("1988-08-22");
    stu.setS_sex("男");
    studentMapper.insertOne(stu);
    //增、删、改需要提交事务，否则不会修改
    sqlSession.commit();
    sqlSession.close();
  }

  @Test
  public void testDeleteByName() {
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
    studentMapper.deleteByName("李水");
    sqlSession.commit();
    sqlSession.close();
  }

  @Test
  public void testUpdateByName() {
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
    Student stu = new Student();
    stu.setS_name("李水");
    stu.setS_birth("1999-01-22");
    stu.setS_sex("女");
    studentMapper.updateByName(stu);
    sqlSession.commit();
    sqlSession.close();
  }
}

测试查询结果

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。