SpringBoot+Thymeleaf+mybatis+mysql简单入门增删查改案例
1.先决条件
JDK1.8、JPA相关知识、Mysql相关知识、Thymeleaf相关知识、SpringBoot构建项目，不了解的朋友可以看一下我前面的博
文。
thymeleaf入门
2.数据准备
- 创建数据库和表
create database thymeleaf;
use thymeleaf;
CREATE TABLE user (
id int(11) NOT NULL AUTO_INCREMENT,
name varchar(30),
PRIMARY KEY (id)
) DEFAULT CHARSET=UTF8;
- 添加15条数据方便测试
INSERT INTO user VALUES (1,'name1');
INSERT INTO user VALUES (2,'name2');
INSERT INTO user VALUES (3,'name3');
INSERT INTO user VALUES (4,'name4');
INSERT INTO user VALUES (5,'name5');
INSERT INTO user VALUES (6,'name6');
INSERT INTO user VALUES (7,'name7');
INSERT INTO user VALUES (8,'name8');
INSERT INTO user VALUES (9,'name9');
INSERT INTO user VALUES (10,'name10');
INSERT INTO user VALUES (11,'name11');
INSERT INTO user VALUES (12,'name12');
INSERT INTO user VALUES (13,'name13');
INSERT INTO user VALUES (14,'name14');
INSERT INTO user VALUES (15,'name15');
3. 新建项目
模板选上web，模板引擎选择Thymeleaf
3.1 修改pom.xml文件
添加mybatis、mysql、分页工具pageHelper 的 依赖，最后依赖的配置如下：
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- servlet依赖. -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
</dependency>
<!-- tomcat的支持.-->
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
</dependency>
<!-- 添加mybatis的依赖 -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.3</version>
</dependency>
<!-- 添加mysql的依赖 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.15</version><!--我装的是8.0.15，根据个人选择相应版本-->
</dependency>
<!-- pageHelper 用于分页 -->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>4.1.6</version>
</dependency>
</dependencies>
3.2 修改application.properties文件
#thymeleaf 配置
spring.thymeleaf.mode=HTML5
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.servlet.content-type=text/html
#缓存设置为false, 这样修改之后马上生效，便于调试
spring.thymeleaf.cache=false
#上下文,可以不需要，如果加上则要在浏览器url加上/thymeleaf
#server.servlet.context-path=/thymeleaf
#数据库配置
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/thymeleaf?useSSL=false&serverTimezone=GMT%2B8&allowPublicKeyRetrieval=true
spring.datasource.username=root
spring.datasource.password=666666
#由于我用得是Mysql8.0 所以驱动类是 com.mysql.cj.jdbc.Driver如果是其他版本请改成com.mysql.jdbc.Driver
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
3.3 添加实体类
新建一个pojo包，新建一个实体类User
package com.eknaij.springbootthymeleaf.pojo;
public class User {
Integer id;
String name;
public Integer getId() { return id; }
public void setId(Integer id) { this.id = id; }
public String getName() { return name;
}
public void setName(String name) { this.name = name; }}
3.4 添加Mapper
新建一个mapper包，用于存放mapper接口文件
新建一个UserMapper接口
package com.eknaij.springbootthymeleaf.mapper;
import com.eknaij.springbootthymeleaf.pojo.User;
import org.apache.ibatis.annotations.*;
import java.util.List;
@Mapper
public interface UserMapper {
@Select("select * from user ")
List<User> findAll();
@Insert(" insert into user (name) values (#{name}) ")
public int save(User user);
@Delete(" delete from user where id= #{id} ")
public void delete(int id);
@Select("select * from user where id= #{id} ")
public User get(int id);
@Update("update user set name=#{name} where id=#{id} ")
public int update(User user);
}
3.5 添加config包
添加config包，用于存放分页相关的配置类
新建用于分页配置的PageHelperConfig类
package com.eknaij.springbootthymeleaf.config;
import com.github.pagehelper.PageHelper;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.util.Properties;
@Configuration
public class PageHelperConfig {
@Bean
public PageHelper pageHelper() {
PageHelper pageHelper = new PageHelper();
Properties properties = new Properties();
properties.setProperty("offsetAsPageNum", "true");
properties.setProperty("rowBoundsWithCount", "true");
properties.setProperty("reasonable", "true");
pageHelper.setProperties(properties);
return pageHelper;
}
}
3.6 新建controller
新建一个controller包，存放相关controller类
新建一个UserController
package com.eknaij.springbootthymeleaf.controller;
import com.eknaij.springbootthymeleaf.mapper.UserMapper;
import com.eknaij.springbootthymeleaf.pojo.User;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@Controller
public class UserController {
@Autowired
UserMapper userMapper;
//添加
@RequestMapping("/addUser")
public String listUser(User user) throws Exception {
userMapper.save(user);
return "redirect:listUser";
}
//删除
@RequestMapping("/deleteUser")
public String deleteUser(User user) throws Exception {
userMapper.delete(user.getId());
return "redirect:listUser";
}
//修改
@RequestMapping("/updateUser")
public String updateUser(User user) throws Exception {
userMapper.update(user);
return "redirect:listUser";
}
//查找(用于修改)
@RequestMapping("/findUser")
public String findUser(int id, Model model) throws Exception {
User user= userMapper.get(id);
model.addAttribute("user", user);
return "edituser";
}
//遍历
@RequestMapping("/listUser")
public String listUser(Model model, @RequestParam(value = "start", defaultValue = "0") int start,
@RequestParam(value = "size", defaultValue = "5") int size) throws Exception {
PageHelper.startPage(start,size,"id asc");
List<User> userList=userMapper.findAll();
PageInfo<User> page = new PageInfo<>(userList);
model.addAttribute("pages", page);
return "listuser";
}
}
3.7 html页面
涉及到一些Thymeleaf的标签，如果不了解可以查看我的上一篇文章：Thymeleaf介绍以及常用标签
- 在resources/templates目录下新建一个layout.html页面（所有页面都建立在这个文件夹里），用于设置布局
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>test</title>
</head>
<body>
<header th:fragment="header">
布局的head
</header>
<div th:replace="::content">
这是正文
</div>
<footer th:fragment="footer">
布局的foot
</footer>
</body>
</html>
这个布局只是简单的上中下三部分，在此只是简单示范一下thylemeaf的布局使用方法，不做具体样式。本页面相当于模板，在页面布局一致的情况下，只要修改content就好了。这个页面关键的地方在于：
- 新建一个listuser.html用于显示所有的User
<!DOCTYPE html> <html lang="en" xmlns:th="http://www.thymeleaf.org" th:replace="layout"> <head> <meta http-equiv="Content-Type" content="text/html;charset=UTF-8"/> <title>遍历User</title> </head> <body> <div th:fragment="content" style="width:500px;margin:20px auto;text-align: center" > <table align='center' border='1' cellspacing='0'> <tr> <td>id</td> <td>name</td> <td>编辑</td> <td>删除</td> </tr> <tr th:each="c:${pages.list}"> <td th:text="${c.id}">1</td> <td th:text="${c.name}">name</td> <td><a th:href="@{/findUser(id=${c.id})}">编辑</a></td> <td><a th:href="@{/deleteUser(id=${c.id})}">删除</a></td> </tr> </table> <br/> <div> <a th:href="@{/listUser(start=0)}">[首 页]</a> <a th:href="@{/listUser(start=${pages.pageNum-1})}">[上一页]</a> <a th:href="@{/listUser(start=${pages.pageNum+1})}">[下一页]</a> <a th:href="@{/listUser(start=${pages.pages})}">[末 页]</a> </div> <br/> <form action="addUser" method="post"> name: <input name="name"/> <br/> <button type="submit">添加</button> </form> </div> </body> </html>注意第二行的
th:replace="layout"，还有主体DIV的th:fragment="content"
- 新建一个edituser.html用于修改User
<!DOCTYPE HTML> <html xmlns:th="http://www.thymeleaf.org"> <head> <title>修改User</title> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> </head> <body> <div style="margin:0px auto; width:500px"> <form action="updateUser" method="post"> name: <input name="name" th:value="${user.name}"/> <br/> <input name="id" type="hidden" th:value="${user.id}"/> <button type="submit">提交</button> </form> </div> </body> </html>3.8 项目结构
文中未提及的类和hello.html可忽略，之前练习thymeleaf时留下的，就不删除了。4. 运行测试
运行结果如下：
head和foot是我们布局文件中的内容（真丑= =），中间的表格才是我们的主体。
5. 总结
用thymeleaf模板引擎和使用JSP开发web项目大同小异，关键是要注意thymeleaf的一些属性与JSP有所差异，两个布局方法也有所不同，对于前后端分离来说，用thymeleaf来开发更方便。
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