Spring框架-xml方式访问数据库

目录

1.创建一个数据表

2.在pom.xml文件导入相关依赖

3.编写实体User类

4.写入配置文件db.properties

5.创建并编写UserMappper接扣及UserMapperImpl类

6.创建并编写UserService接口和UserServiceImpl类

7. 创建UserController类

8.创建applicationContext.xml配置文件

9.创建测试类进行测试

1.创建一个数据表

        例如：

CREATE TABLE T_USER(
	id INT,
	username VARCHAr(20),
	PASSWORD VARCHAr(20)
)
    
INSERT INTO T_USER(id,username,PASSWORD) VALUES(1001,'jack','123');
INSERT INTO T_USER(id,username,PASSWORD) VALUES(1002,'tom','456');
INSERT INTO T_USER(id,username,PASSWORD) VALUES(1003,'rose','789');

2.在pom.xml文件导入相关依赖

    
        org.springframework
        spring-context
        5.3.10
    

    
    
        org.springframework
        spring-jdbc
        5.3.10
    

    
        mysql
        mysql-connector-java
        8.0.26
    

    
        com.alibaba
        druid
        1.2.6
    

    
        org.projectlombok
        lombok
        1.18.20
    

    
        junit
        junit
        4.13.2
    

3.编写实体User类

import lombok.Data;
@Data
public class User {
        private Integer id;
        private String name;
        private String password;
}

4.写入配置文件db.properties

db.username = root
db.password = root
db.driverClassName = com.mysql.cj.jdbc.Driver
db.url = jdbc:mysql://localhost:3306/user?serverTimezone=Asia/Shanghai&characterEncoding=UTF8

5.创建并编写UserMappper接口及UserMapperImpl类

        此时，设访问数据库目的是为了找到所有数据，可在UserMapper接口编写

        public List findAll();

        在UserMapperImpl类：

public class UserMapperImpl implements UserMapper {

    private JdbcTemplate jdbcTemplate;

    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    @Override
    public List findAll() {
        String sql = "select id,name,password from t_user";
        List users = jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(User.class));
        return users;
    }
}

6.创建并编写UserService接口和UserServiceImpl类

        此时，设访问数据库目的是为了找到所有数据，可在UserService接口编写

        public List findAll();

        在UserServiceImpl类中：

public class UserServiceImpl implements UserService {
    private UserMapper userMapper;

    public void setUserMapper(UserMapper userMapper) {
        this.userMapper = userMapper;
    }
    @Override
    public List findAll() {
        return userMapper.findAll();
    }
}

7. 创建UserController类

public class UserController {
    private UserService userService;

    public void setUserService(UserService userService) {
        this.userService = userService;
    }
    public List findAll(){
        return userService.findAll();
    } 
}

8.创建applicationContext.xml配置文件

9.创建测试类进行测试

    @Test
    public void findAll(){
        ClassPathXmlApplicationContext applicationContext =
                new ClassPathXmlApplicationContext("applicationContext.xml");
        UserController userController =
                (UserController) applicationContext.getBean("userController");
        List users = userController.findAll();
        System.out.println(users);
    }

        查询结果