第十四节:SpringBoot 使用 JdbcTemplate 访问操作数据库基本用法

create table user(  id int primary key auto_increment,  name varchar(100) not null default '',  domain varchar(100) not null default '')engine=innodb default charset=utf8;

<dependency>  <groupId>org.springframework.boot</groupId>  <artifactId>spring-boot-starter-jdbc</artifactId></dependency><dependency>  <groupId>mysql</groupId>  <artifactId>mysql-connector-java</artifactId>  <scope>runtime</scope></dependency>

spring.datasource.url=jdbc:mysql://localhost:3306/rumenz_springbootspring.datasource.username=rootspring.datasource.password=root1234spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

@Builder@Data@AllArgsConstructorpublic class User  implements RowMapper {    private Integer id;    private String name;    private String domain;
    @Override    public Object mapRow(ResultSet rs, int rowNum) throws SQLException {        User user=new User();        user.setId(rs.getInt("id"));        user.setName(rs.getString("name"));        user.setDomain(rs.getString("domain"));        return user;    }}

package com.rumenz.lession14.controller.service;
import com.rumenz.lession14.controller.entity.User;
import java.util.List;
/** * @className: UserService * @description: TODO 类描述 * @author: 入门小站 rumenz.com * @date: 2021/12/13 **/public interface UserService {    Integer save(User user);    List<User> list();    Integer update(User user);
    Integer batchSave();}

package com.rumenz.lession14.controller.service.Impl;
import com.fasterxml.jackson.core.JsonProcessingException;import com.fasterxml.jackson.databind.ObjectMapper;import com.fasterxml.jackson.databind.json.JsonMapper;import com.rumenz.lession14.controller.entity.User;import com.rumenz.lession14.controller.service.UserService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.jdbc.core.BeanPropertyRowMapper;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.stereotype.Service;
import java.util.ArrayList;import java.util.List;
/** * @className: UserServiceImpl * @description: TODO 类描述 * @author: 入门小站 rumenz.com * @date: 2021/12/13 **/
@Servicepublic class UserServiceImpl implements UserService {    @Autowired    private JdbcTemplate jdbcTemplate;
    @Override    public Integer save(User user) {        int reint = jdbcTemplate.update("insert into user(name,domain) values (?,?)", user.getName(), user.getDomain());        return reint;    }
    @Override    public Integer batchSave() {        String sql="insert into user(name,domain) values(?,?)";        List<Object[]> par=new ArrayList<>();        for (int i = 0; i < 10; i++) {            String[] s=new String[2];            s[0]="入门小站"+i;            s[1]="https://rumenz.com/"+i;            par.add(s);        }        int[] ints = jdbcTemplate.batchUpdate(sql, par);        System.out.println(ints.toString());        return 0;    }
    @Override    public List<User> list() {        //User实现RowMapper接口，实现接口里的mapRow方法。        List<User> list = jdbcTemplate.query("select * from user",new User());        return list;    }
    @Override    public Integer update(User user) {        Integer reint=jdbcTemplate.update("update user set name=?,domain=? where id=?", user.getName(),user.getDomain(),user.getId());        //        return reint;    }

}

package com.rumenz.lession14.controller;
import com.fasterxml.jackson.core.JsonProcessingException;import com.fasterxml.jackson.databind.ObjectMapper;import com.rumenz.lession14.controller.entity.User;import com.rumenz.lession14.controller.service.UserService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;
import java.util.List;
/** * @className: RumenzController * @description: TODO 类描述 * @author: 入门小站 rumenz.com * @date: 2021/12/13 **/@RestController@RequestMapping("/rumenz")public class RumenzController {

    @Autowired    private UserService userService;

    //添加数据    @GetMapping("/save")    public String save(){        User user=User.builder().name("入门小站").domain("https://rumenz.com").build();        Integer reint = userService.save(user);        return reint.toString();    }
    //批量添加数据    @GetMapping("/batchSave")    public String batchSave(){        Integer reint = userService.batchSave();        return reint.toString();    }
    //查询数据    @GetMapping("/list")    public String list() throws JsonProcessingException {        List<User> list = userService.list();        ObjectMapper objectMapper=new ObjectMapper();        String val = objectMapper.writeValueAsString(list);        return val;    }    //更新数据    @GetMapping("/update")    public String update() throws JsonProcessingException {        User user=User.builder().id(1).name("入门小站-修改").domain("https://tooltt.com").build();        Integer reint = userService.update(user);        return reint.toString();    }
}