springboot 整合 thymeleaf 做增删改查 CRUD和分页

更多内容，点击了解： https://how2j.cn/k/springboot/springboot-crud/1742.html

目录

步骤 1 : 基于前面的知识点

步骤 2 : 先运行，看到效果，再学习

步骤 3 : 模仿和排错

步骤 4 : 表结构和数据

步骤 5 : application.properties

步骤 6 : pom.xml

步骤 7 : Category

步骤 8 : CategoryMapper

步骤 9 : CategoryController

步骤 10 : PageHelperConfig

步骤 11 : listCategory.html

步骤 12 : editCategory.html

步骤 13 : 重启测试

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步骤 1 : 基于前面的知识点

本知识点是建立在上一个知识点可运行项目的基础上进行的改进,所以最好把上个知识点理解和消化了.

步骤 2 : 先运行，看到效果，再学习

老规矩，先下载下载区(点击进入)的可运行项目，配置运行起来，确认可用之后，再学习做了哪些步骤以达到这样的效果。 
运行 Application.java ，然后访问地址：

http://127.0.0.1:8080/thymeleaf/listCategory

步骤 3 : 模仿和排错

在确保可运行项目能够正确无误地运行之后，再严格照着教程的步骤，对代码模仿一遍。 
模仿过程难免代码有出入，导致无法得到期望的运行结果，此时此刻通过比较正确答案 ( 可运行项目 ) 和自己的代码，来定位问题所在。 
采用这种方式，学习有效果，排错有效率，可以较为明显地提升学习速度，跨过学习路上的各个槛。 
推荐使用diffmerge软件，进行文件夹比较。把你自己做的项目文件夹，和我的可运行项目文件夹进行比较。 
这个软件很牛逼的，可以知道文件夹里哪两个文件不对，并且很明显地标记出来 
这里提供了绿色安装和使用教程：diffmerge 下载和使用教程

步骤 4 : 表结构和数据

create database how2java; use how2java; CREATE TABLE category_ (   id int(11) NOT NULL AUTO_INCREMENT,   name varchar(30),   PRIMARY KEY (id) ) DEFAULT CHARSET=UTF8;

步骤 5 : application.properties

增加数据库相关配置

#数据库 spring.datasource.url=jdbc:mysql://127.0.0.1:3306/how2java?characterEncoding=UTF-8 spring.datasource.username=root spring.datasource.password=admin spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#thymeleaf 配置 spring.thymeleaf.mode=HTML5 spring.thymeleaf.encoding=UTF-8 spring.thymeleaf.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 server.context-path=/thymeleaf #数据库 spring.datasource.url=jdbc:mysql://127.0.0.1:3306/how2java?characterEncoding=UTF-8 spring.datasource.username=root spring.datasource.password=admin spring.datasource.driver-class-name=com.mysql.jdbc.Driver

步骤 6 : pom.xml

修改pom.xml, 增加 jdbc,mybatis, pageHelper 的jar包

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">     <modelVersion>4.0.0</modelVersion>   <groupId>com.how2java</groupId>   <artifactId>thymeleaf</artifactId>   <version>0.0.1-SNAPSHOT</version>   <name>thymeleaf</name>   <description>thymeleaf</description>   <packaging>war</packaging>     <parent>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter-parent</artifactId>         <version>1.5.9.RELEASE</version>     </parent>     <dependencies>         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-web</artifactId>         </dependency>         <dependency>           <groupId>org.springframework.boot</groupId>           <artifactId>spring-boot-starter-thymeleaf</artifactId>         </dependency>         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-tomcat</artifactId>         </dependency>         <dependency>               <groupId>junit</groupId>               <artifactId>junit</artifactId>               <version>3.8.1</version>               <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>             <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-devtools</artifactId>             <optional>true</optional> <!-- 这个需要为 true 热部署才有效 -->         </dependency>            <!-- mybatis -->         <dependency>             <groupId>org.mybatis.spring.boot</groupId>             <artifactId>mybatis-spring-boot-starter</artifactId>             <version>1.1.1</version>         </dependency>         <!-- mysql -->         <dependency>             <groupId>mysql</groupId>             <artifactId>mysql-connector-java</artifactId>             <version>5.1.21</version>         </dependency>             <!-- pageHelper -->         <dependency>             <groupId>com.github.pagehelper</groupId>             <artifactId>pagehelper</artifactId>             <version>4.1.6</version>         </dependency>     </dependencies>     <properties>         <java.version>1.8</java.version>     </properties>     <build>         <plugins>             <plugin>                 <groupId>org.springframework.boot</groupId>                 <artifactId>spring-boot-maven-plugin</artifactId>             </plugin>         </plugins>     </build> </project>

步骤 7 : Category

增加实体类

package com.how2java.springboot.pojo; public class Category {     private int id;     private String name;     public int getId() {         return id;     }     public void setId(int id) {         this.id = id;     }     public String getName() {         return name;     }     public void setName(String name) {         this.name = name;     } }

步骤 8 : CategoryMapper

增加Mapper类

package com.how2java.springboot.mapper; import java.util.List; import org.apache.ibatis.annotations.Delete; import org.apache.ibatis.annotations.Insert; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Select; import org.apache.ibatis.annotations.Update; import com.how2java.springboot.pojo.Category; @Mapper public interface CategoryMapper {     @Select("select * from category_ ")     List<Category> findAll();     @Insert(" insert into category_ ( name ) values (#{name}) ")     public int save(Category category);     @Delete(" delete from category_ where id= #{id} ")     public void delete(int id);     @Select("select * from category_ where id= #{id} ")     public Category get(int id);     @Update("update category_ set name=#{name} where id=#{id} ")     public int update(Category category); }

步骤 9 : CategoryController

增加控制类

package com.how2java.springboot.web; import java.util.List; 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 com.github.pagehelper.PageHelper; import com.github.pagehelper.PageInfo; import com.how2java.springboot.mapper.CategoryMapper; import com.how2java.springboot.pojo.Category; @Controller public class CategoryController {     @Autowired CategoryMapper categoryMapper;     @RequestMapping("/addCategory")     public String listCategory(Category c) throws Exception {         categoryMapper.save(c);         return "redirect:listCategory";     }     @RequestMapping("/deleteCategory")     public String deleteCategory(Category c) throws Exception {         categoryMapper.delete(c.getId());         return "redirect:listCategory";     }     @RequestMapping("/updateCategory")     public String updateCategory(Category c) throws Exception {         categoryMapper.update(c);         return "redirect:listCategory";     }     @RequestMapping("/editCategory")     public String listCategory(int id,Model m) throws Exception {         Category c= categoryMapper.get(id);         m.addAttribute("c", c);         return "editCategory";     }     @RequestMapping("/listCategory")     public String listCategory(Model m,@RequestParam(value = "start", defaultValue = "0") int start,@RequestParam(value = "size", defaultValue = "5") int size) throws Exception {         PageHelper.startPage(start,size,"id desc");         List<Category> cs=categoryMapper.findAll();         PageInfo<Category> page = new PageInfo<>(cs);         m.addAttribute("page", page);                return "listCategory";     } }

步骤 10 : PageHelperConfig

配置 PageHealper

package com.how2java.springboot.config; import java.util.Properties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import com.github.pagehelper.PageHelper; @Configuration public class PageHelperConfig {     @Bean     public PageHelper pageHelper() {         PageHelper pageHelper = new PageHelper();         Properties p = new Properties();         p.setProperty("offsetAsPageNum", "true");         p.setProperty("rowBoundsWithCount", "true");         p.setProperty("reasonable", "true");         pageHelper.setProperties(p);         return pageHelper;     } }

步骤 11 : listCategory.html

增加和查询的页面 listCategory.html

<!DOCTYPE HTML> <html xmlns:th="http://www.thymeleaf.org"> <head>     <title>hello</title>     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> </head> <body> <div 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:${page.list}">             <td th:text="${c.id}"></td>             <td th:text="${c.name}"></td>             <td><a th:href="@{/editCategory(id=${c.id})}">编辑</a></td>             <td><a th:href="@{/deleteCategory(id=${c.id})}">删除</a></td>         </tr>     </table>     <br/>     <div>             <a th:href="@{/listCategory(start=0)}">[首  页]</a>             <a th:href="@{/listCategory(start=${page.pageNum-1})}">[上一页]</a>             <a th:href="@{/listCategory(start=${page.pageNum+1})}">[下一页]</a>             <a th:href="@{/listCategory(start=${page.pages})}">[末  页]</a>     </div>     <br/>        <form action="addCategory" method="post">     name: <input name="name"/> <br/>     <button type="submit">提交</button>     </form> </div> </body> </html>

步骤 12 : editCategory.html

修改页面

<!DOCTYPE HTML> <html xmlns:th="http://www.thymeleaf.org"> <head>     <title>hello</title>     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> </head> <body> <div style="margin:0px auto; width:500px">     <form action="updateCategory" method="post">     name: <input name="name" th:value="${c.name}"/> <br/>     <input name="id" type="hidden" th:value="${c.id}"/>     <button type="submit">提交</button>     </form> </div> </body> </html>

步骤 13 : 重启测试

重新运行 Application.java 然后访问地址：

http://127.0.0.1:8080/thymeleaf/listCategory

更多内容，点击了解： https://how2j.cn/k/springboot/springboot-crud/1742.html