SpringBoot整合Mybatis與thymleft實現增刪改查功能詳解

2022-12-03 14:00:47

首先我們先建立專案注意：建立SpringBoot專案時一定要聯網不然會報錯

專案建立好後我們首先對 application.yml 進行編譯

#指定埠號
server:
port: 8888
#設定mysql資料來源
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/nba?serverTimezone=Asia/Shanghai
username: root
password: root
#設定模板引擎 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：後一定要空格，這是他的語法，不空格就會執行報錯

接下來我們進行對專案的構建建立好如下幾個包可根據自己實際需要建立其他的工具包之類的

mapper：用於存放dao層介面

pojo：用於存放實體類

service：用於存放service層介面，以及service層實現類

web：用於存放controller控制層

接下來我們開始編寫程式碼

首先是實體類，今天做的是一個兩表的簡單增刪改查

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註解可以有效減少實體類中的程式碼數量，縮減了對於get/set和toString的編寫

然後是mapper層

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 {
    /**
     * 查詢所有
     * @return
     */
    List<Players> findAll();
    /**
     * 根據ID查詢
     * @return
     */
    Players findById(Integer id);
    /**
     * 新增
     * @param players
     * @return
     */
    Integer add(Players players);
    /**
     * 刪除
     * @param pid
     * @return
     */
    Integer delete(Integer pid);
    /**
     * 修改
     * @param players
     * @return
     */
    Integer update(Players players);
}

使用@mapper後，不需要在spring設定中設定掃描地址，通過mapper.xml裡面的namespace屬性對應相關的mapper類，spring將動態的生成Bean後注入到Servicelmpl中。

然後是service層

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);
    }
}

最後是web層的controller控制類

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方法僅僅是用於跳轉頁面，並沒有其他作用，如果有更好的跳轉方法可以給我留言哦

現在準備工作都做完了，可以開始編寫SQL語句了

mapper.xml可以寫在下面resources裡面也可以寫在上面的mapper層裡

如果寫在上面的話需要在pom裡面寫一個資源過濾器，有興趣的話可以去百度

<?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=繫結一個對應的Dao/Mapper介面-->
<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裡對應的是mapper層介面的方法，一定不能寫錯

到現在為止我們的後端程式碼就已經完全搞定了，前端頁面如下

主頁 index.html

<html>
<head>
    <title>Title</title>
</head>
<body>
<div align="center">
    <table border="1">
        <h1>美國職業籃球聯盟(NBA)球員資訊</h1>
        <a th:href="@{/a1}" rel="external nofollow" >新增</a>
        <tr>
            <th>球員編號</th>
            <th>球員名稱</th>
            <th>出生時間(yyyy-MM-dd)</th>
            <th>球員身高(cm)</th>
            <th>球員體重(kg)</th>
            <th>球員位置</th>
            <th>所屬球隊</th>
            <th>相關操作</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" >刪除</a>
                </td>
            </tr>
        </c:forEach>
    </table>
</div>
</body>
</html>

新增頁 add.html

<!DOCTYPE html>
<html>
      <head>
      <title>Title</title>
</head>
<body>
<div align="center">
  <h3 align="center">新增球員</h3>
  <form action="/add">
    <p>
      球員名稱：
      <input name="pname" id="pname">
    </p >
    <p>
      出生日期：
      <input name="birthday" id="birthday">
    </p >
    <p>
      球員升高：
      <input name="height" id="height">
    </p >
    <p>
      球員體重：
      <input name="weight" id="weight">
    </p >
    <p>
      球員位置:
      <input type="radio"  name="position" value="控球后衛"/>控球后衛
      <input type="radio"  name="position" value="得分後衛"/>得分後衛
      <input type="radio"  name="position" value="小前鋒" />小前鋒
      <input type="radio"  name="position" value="大前鋒" />大前鋒
      <input type="radio"  name="position" value="中鋒"/>中鋒
    </p >
    <p>
      所屬球隊：
      <select name="cid">
        <option value="1">熱火隊</option>
        <option value="2">奇才隊</option>
        <option value="3">魔術隊</option>
        <option value="4">山貓隊</option>
        <option value="5">老鷹隊</option>
      </select>
    </p >
    <input type="submit" value="儲存">
    <input type="reset" value="重置">
  </form>
</div>
</body>
</html>

修改頁 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>修改球員資訊</h1>
      <br/>
      <form action="/update" method="get" id="form2">
        <table>
          <tr>
            <td colspan="2"></td>
          </tr>
          <tr>
            <td>球員編號:</td>
            <td><input type="text" name="pid"
                                    id="pid" th:value="${list.pid}"/></td>
          </tr>
          <tr>
            <td>球員姓名:</td>
            <td><input type="text" name="pname"
                                    id="pname" th:value="${list.pname}"/></td>
          </tr>
          <tr>
            <td>出身日期:</td>
            <td><input type="text" name="birthday"
                                    id="birthday" th:value="${list.birthday}"/></td>
          </tr>
          <tr>
            <td>球員身高:</td>
            <td><input type="text" name="height"
                                    id="height" th:value="${list.height}"/></td>
          </tr>
          <tr>
            <td>球員體重:</td>
            <td><input type="text" name="weight"
                                    id="weight" th:value="${list.weight}"/></td>
          </tr>
          <tr>
            <td>球員位置:</td>
            <td><input type="text" name="position"
                                    id="position" th:value="${list.position}"/></td>
          </tr>
          <tr>
            <td>所屬球隊:</td>
            <td>
              <select name="cid" id="cid" th:value="${list.cid}"/>
              <option value="">--請選擇球隊--</option>
              <option value="1">熱火隊</option>
              <option value="2">奇才隊</option>
              <option value="3">魔術隊</option>
              <option value="4">山貓隊</option>
              <option value="5">老鷹隊</option>
              </select></td>
          </tr>
          <tr>
            <td colspan="2"><input type="submit" id="btn2" value="儲存"/>
              <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>

資料庫建立原始碼 -- 注意：我用的是MySQL資料庫

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,'熱火隊','邁阿密'),
(2,'奇才隊','華盛頓'),
(3,'魔術隊','奧蘭多'),
(4,'山貓隊','夏洛特'),
(5,'老鷹隊','亞特蘭大')
insert into players values
(4,'多多','1989-08-08',213,186,'前鋒',1),
(5,'西西','1987-10-16',199,162,'中鋒',1),
(6,'南南','1990-01-23',221,184,'後鋒',1)

最後給大家看一下頁面展示

在位址列輸入：http://localhost:8888/findAll 進入到查詢所有方法再跳轉到idnex.html進行顯示