SpringBoot整合Mybatis与thymleft实现增删改查功能详解

披着星光的鲸鱼 2022-12-02 我要评论

首先我们先创建项目注意：创建SpringBoot项目时一定要联网不然会报错

项目创建好后我们首先对 application.yml 进行编译

#指定端口号
server:
port: 8888
#配置mysql数据源
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/nba?serverTimezone=Asia/Shanghai
username: root
password: root
#配置模板引擎 thymeleaf
thymeleaf:
mode: HTML5
cache: false
suffix: .html
prefix: classpath:/templates/
mybatis:
mapper-locations: classpath:/mapper/*.xml
type-aliases-package: com.bdqn.springboot #放包名

注意：在：后一定要空格，这是他的语法，不空格就会运行报错

接下来我们进行对项目的构建创建好如下几个包可根据自己实际需要创建其他的工具包之类的

mapper：用于存放dao层接口

pojo：用于存放实体类

service：用于存放service层接口，以及service层实现类

web：用于存放controller控制层

接下来我们开始编写代码

首先是实体类，今天做的是一个两表的简单增删改查

package com.baqn.springboot.pojo;
import lombok.Data;
@Data
public class Clubs {
    private int cid;
    private String cname;
    private String city;
}

package com.baqn.springboot.pojo;
import lombok.Data;
@Data
public class Players {
    private int pid;
    private String pname;
    private String birthday;
    private int height;
    private int weight;
    private String position;
    private int cid;
    private String cname;
    private String city;
}

使用@Data注解可以有效减少实体类中的代码数量，缩减了对于get/set和toString的编写

然后是mapper层

package com.baqn.springboot.mapper;
import com.baqn.springboot.pojo.Players;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;
import java.util.List;
@Mapper
@Repository
public interface PlayersMapper {
    /**
     * 查询所有
     * @return
     */
    List<Players> findAll();
    /**
     * 根据ID查询
     * @return
     */
    Players findById(Integer id);
    /**
     * 新增
     * @param players
     * @return
     */
    Integer add(Players players);
    /**
     * 删除
     * @param pid
     * @return
     */
    Integer delete(Integer pid);
    /**
     * 修改
     * @param players
     * @return
     */
    Integer update(Players players);
}

使用@mapper后，不需要在spring配置中设置扫描地址，通过mapper.xml里面的namespace属性对应相关的mapper类，spring将动态的生成Bean后注入到Servicelmpl中。

然后是service层

package com.baqn.springboot.service;
import com.baqn.springboot.pojo.Players;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface PlayersService {
    List<Players> findAll();
    Players findById(Integer pid);
    Integer add(Players players);
    Integer delete(Integer pid);
    Integer update(Players players);
}

package com.baqn.springboot.service;
import com.baqn.springboot.mapper.PlayersMapper;
import com.baqn.springboot.pojo.Players;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class PlayersServiceImpl implements  PlayersService{
    @Autowired
    private PlayersMapper mapper;
    @Override
    public List<Players> findAll() {
        return mapper.findAll();
    }
    @Override
    public Players findById(Integer pid) {
        return mapper.findById(pid);
    }
    @Override
    public Integer add(Players players) {
        return mapper.add(players);
    }
    @Override
    public Integer delete(Integer pid) {
        return mapper.delete(pid);
    }
    @Override
    public Integer update(Players players) {
        return mapper.update(players);
    }
}

最后是web层的controller控制类

package com.baqn.springboot.web;
import com.baqn.springboot.pojo.Players;
import com.baqn.springboot.service.PlayersServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import java.util.List;
@Controller
public class PlayersController {
    @Autowired
    private PlayersServiceImpl service;
    @RequestMapping("/findAll")
    public String findAll(Model model) {
        List<Players> allList = service.findAll();
        model.addAttribute("allList",allList);
        return "index";
    }
    @RequestMapping("/findById/{pid}")
    public String findById(Model model,@PathVariable("pid") Integer pid) {
        Players list = service.findById(pid);
        //System.out.println("---------------"+list.toString());
        model.addAttribute("list",list);
        return "update.html";
    }
    @RequestMapping("/add")
    public String add(Model model, Players players){
        Integer count = service.add(players);
        if (count>0){
            return "redirect:/findAll";
        }
        return "add";
    }
    @RequestMapping("/delete/{pid}")
    public String delete(Model model,@PathVariable("pid") Integer pid){
        Integer count = service.delete(pid);
        if (count>0){
            return "redirect:/findAll";
        }
        return null;
    }
    @RequestMapping("/a1")
    public String a1(Model model, Players players){
        return "add.html";
    }
    @RequestMapping("/update")
    public String update(Model model,Players plays){
        Integer count = service.update(plays);
        if (count>0){
            return "redirect:/findAll";
        }
        return null;
    }
}

注意：a1方法仅仅是用于跳转页面，并没有其他作用，如果有更好的跳转方法可以给我留言哦

现在准备工作都做完了，可以开始编写SQL语句了

mapper.xml可以写在下面resources里面也可以写在上面的mapper层里

如果写在上面的话需要在pom里面写一个资源过滤器，有兴趣的话可以去百度

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--namespace=绑定一个对应的Dao/Mapper接口-->
<mapper namespace="com.baqn.springboot.mapper.PlayersMapper">
    <select id="findAll" resultType="com.baqn.springboot.pojo.Players">
        select * from clubs c , players p
        where c.cid = p.cid
    </select>
    <select id="findById" resultType="com.baqn.springboot.pojo.Players">
        select * from clubs c , players p
        where c.cid = p.cid and p.pid=#{pid}
    </select>
    <insert id="add" parameterType="com.baqn.springboot.pojo.Players">
        INSERT INTO `nba`.`players`(pname, birthday, height, weight, position, cid)
        VALUES (#{pname}, #{birthday}, #{height}, #{weight}, #{position}, #{cid});
    </insert>
    <delete id="delete" parameterType="int">
        delete from players where pid = #{pid}
    </delete>
    <update id="update" parameterType="com.baqn.springboot.pojo.Players">
        UPDATE `nba`.`players`
        <set>
            <if test="pname != null">pname=#{pname},</if>
            <if test="birthday != null">birthday=#{birthday},</if>
            <if test="height != null">height=#{height},</if>
            <if test="weight != null">weight=#{weight},</if>
            <if test="position != null">position=#{position},</if>
            <if test="cid != null">cid=#{cid}</if>
        </set>
        WHERE `pid` = #{pid};
    </update>
</mapper>

注意：mapper.xml中的id里对应的是mapper层接口的方法，一定不能写错

到现在为止我们的后端代码就已经完全搞定了，前端页面如下

主页 index.html

<html>
<head>
    <title>Title</title>
</head>
<body>
<div align="center">
    <table border="1">
        <h1>美国职业篮球联盟(NBA)球员信息</h1>
        <a th:href="@{/a1}" rel="external nofollow" >新增</a>
        <tr>
            <th>球员编号</th>
            <th>球员名称</th>
            <th>出生时间(yyyy-MM-dd)</th>
            <th>球员身高(cm)</th>
            <th>球员体重(kg)</th>
            <th>球员位置</th>
            <th>所属球队</th>
            <th>相关操作</th>
        </tr>
        <!--/*@thymesVar id="abc" type=""*/-->
        <tr th:each="list : ${allList}">
                <td th:text="${list.pid}"></td>
                <td th:text="${list.pname}"></td>
                <td th:text="${list.birthday}"></td>
                <td th:text="${list.height}">${list.height}</td>
                <td th:text="${list.weight}"></td>
                <td th:text="${list.position}"></td>
                <td th:text="${list.cname}"></td>
                <td>
                    <a th:href="@{'/findById/'+${list.pid}}" rel="external nofollow" >修改</a>
                    <a th:href="@{'/delete/'+${list.pid}}" rel="external nofollow" >删除</a>
                </td>
            </tr>
        </c:forEach>
    </table>
</div>
</body>
</html>

新增页 add.html

<!DOCTYPE html>
<html>
      <head>
      <title>Title</title>
</head>
<body>
<div align="center">
  <h3 align="center">新增球员</h3>
  <form action="/add">
    <p>
      球员名称：
      <input name="pname" id="pname">
    </p >
    <p>
      出生日期：
      <input name="birthday" id="birthday">
    </p >
    <p>
      球员升高：
      <input name="height" id="height">
    </p >
    <p>
      球员体重：
      <input name="weight" id="weight">
    </p >
    <p>
      球员位置:
      <input type="radio"  name="position" value="控球后卫"/>控球后卫
      <input type="radio"  name="position" value="得分后卫"/>得分后卫
      <input type="radio"  name="position" value="小前锋" />小前锋
      <input type="radio"  name="position" value="大前锋" />大前锋
      <input type="radio"  name="position" value="中锋"/>中锋
    </p >
    <p>
      所属球队：
      <select name="cid">
        <option value="1">热火队</option>
        <option value="2">奇才队</option>
        <option value="3">魔术队</option>
        <option value="4">山猫队</option>
        <option value="5">老鹰队</option>
      </select>
    </p >
    <input type="submit" value="保存">
    <input type="reset" value="重置">
  </form>
</div>
</body>
</html>

修改页 update.html

<!DOCTYPE html>
<html  xmlns:th="http://www.thymeleaf.org">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body class="container">
    <div align="center">
      <h1>修改球员信息</h1>
      <br/>
      <form action="/update" method="get" id="form2">
        <table>
          <tr>
            <td colspan="2"></td>
          </tr>
          <tr>
            <td>球员编号:</td>
            <td><input type="text" name="pid"
                                    id="pid" th:value="${list.pid}"/></td>
          </tr>
          <tr>
            <td>球员姓名:</td>
            <td><input type="text" name="pname"
                                    id="pname" th:value="${list.pname}"/></td>
          </tr>
          <tr>
            <td>出身日期:</td>
            <td><input type="text" name="birthday"
                                    id="birthday" th:value="${list.birthday}"/></td>
          </tr>
          <tr>
            <td>球员身高:</td>
            <td><input type="text" name="height"
                                    id="height" th:value="${list.height}"/></td>
          </tr>
          <tr>
            <td>球员体重:</td>
            <td><input type="text" name="weight"
                                    id="weight" th:value="${list.weight}"/></td>
          </tr>
          <tr>
            <td>球员位置:</td>
            <td><input type="text" name="position"
                                    id="position" th:value="${list.position}"/></td>
          </tr>
          <tr>
            <td>所属球队:</td>
            <td>
              <select name="cid" id="cid" th:value="${list.cid}"/>
              <option value="">--请选择球队--</option>
              <option value="1">热火队</option>
              <option value="2">奇才队</option>
              <option value="3">魔术队</option>
              <option value="4">山猫队</option>
              <option value="5">老鹰队</option>
              </select></td>
          </tr>
          <tr>
            <td colspan="2"><input type="submit" id="btn2" value="保存"/>
              <input type="reset" id="wrap-clera" value="重置"/>
              <a th:href="@{/index.html}" rel="external nofollow" ><input type="button" id="btn1" value="返回"/></a>
            </td>
          </tr>
        </table>
      </form>
    </div>
</body>
</html>

数据库创建源码 -- 注意：我用的是MySQL数据库

create table clubs(
		cid int primary key auto_increment,
		cname varchar(50) not null,
		city varchar(50) not null
)
create table players(
		pid int primary key auto_increment,
		pname varchar(50) not null,
		birthday datetime not null,
		height int not null,
		weight int not null,
		position varchar(50) not null,
		cid int not null
)
alter  table  players  add  constraint  players_cid
foreign key(cid)  references  clubs(cid);
insert into clubs values
(1,'热火队','迈阿密'),
(2,'奇才队','华盛顿'),
(3,'魔术队','奥兰多'),
(4,'山猫队','夏洛特'),
(5,'老鹰队','亚特兰大')
insert into players values
(4,'多多','1989-08-08',213,186,'前锋',1),
(5,'西西','1987-10-16',199,162,'中锋',1),
(6,'南南','1990-01-23',221,184,'后锋',1)

最后给大家看一下页面展示

在地址栏输入：http://localhost:8888/findAll 进入到查询所有方法再跳转到idnex.html进行显示