13.SPRINGBOOT使用MYBATIS实现完整的 增删改查 CRUD和分页

pom.xml

顶折
 
增加对PageHelper的支持
 
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>4.1.6</version>
</dependency>
 
 
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<?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>springboot</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>springboot</name>
  <description>springboot</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-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 6 : 

PageHelperConfig

 

注解@Configuration 表示PageHelperConfig 这个类是用来做配置的。
注解@Bean 表示启动PageHelper这个拦截器。

新增加一个包 com.how2java.springboot.config， 然后添加一个类PageHelperConfig ，其中进行PageHelper相关配置。
offsetAsPageNum:设置为true时，会将RowBounds第一个参数offset当成pageNum页码使用.
 
p.setProperty("offsetAsPageNum", "true");
 

rowBoundsWithCount:设置为true时，使用RowBounds分页会进行count查询.
 
p.setProperty("rowBoundsWithCount", "true");
 

reasonable：启用合理化时，如果pageNum<1会查询第一页，如果pageNum>pages会查询最后一页。
 
p.setProperty("reasonable", "true");
注：RowBounds是什么鬼？我也没搞太清楚。。。反正这么复制粘贴就对了 ：|
 
 
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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;
    }
}

CategoryMapper

修改CategoryMapper，增加CRUD方法的支持。 其实就是调用不同的SQL语句。
 
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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); 
 
}

CategoryController

为CategoryController添加： 增加、删除、获取、修改映射
 
@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";
}
 


修改查询映射
 
@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";
}
 

1. 在参数里接受当前是第几页 start ，以及每页显示多少条数据 size。 默认值分别是0和5。
 
@RequestParam(value = "start", defaultValue = "0") int start,@RequestParam(value = "size", defaultValue = "5"
 

2. 根据start,size进行分页，并且设置id 倒排序
 
PageHelper.startPage(start,size,"id desc");
 

3. 因为PageHelper的作用，这里就会返回当前分页的集合了
 
List<Category> cs=categoryMapper.findAll();
 

4. 根据返回的集合，创建PageInfo对象
 
PageInfo<Category> page = new PageInfo<>(cs);
 

5. 把PageInfo对象扔进model，以供后续显示
 
m.addAttribute("page", page);
 

6. 跳转到listCategory.jsp
 
return "listCategory";
 
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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") intstart,@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";
    }
     
}

listCategory.jsp

通过page.getList遍历当前页面的Category对象。
在分页的时候通过page.pageNum获取当前页面，page.pages获取总页面数。
注：page.getList会返回一个泛型是Category的集合。
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<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
  
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
    
<div align="center">
  
</div>
  
<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>
        <c:forEach items="${page.list}" var="c" varStatus="st">
            <tr>
                <td>${c.id}</td>
                <td>${c.name}</td>
                <td><a href="editCategory?id=${c.id}">编辑</a></td>
                <td><a href="deleteCategory?id=${c.id}">删除</a></td>
            </tr>
        </c:forEach>
          
    </table>
    <br>
    <div>
                <a href="?start=1">[首  页]</a>
            <a href="?start=${page.pageNum-1}">[上一页]</a>
            <a href="?start=${page.pageNum+1}">[下一页]</a>
            <a href="?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>

editCategory.jsp

修改分类的页面
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<%@ page language="java" contentType="text/html; charset=UTF-8"
 pageEncoding="UTF-8" isELIgnored="false"%>
  
<div style="margin:0px auto; width:500px">
  
<form action="updateCategory" method="post">
  
name: <input name="name" value="${c.name}"> <br>
  
<input name="id" type="hidden" value="${c.id}">
<button type="submit">提交</button>
  
</form>
</div>

重启测试访问

 
因为在pom中增加了新jar的依赖，所以要手动重启，重启后访问测试地址：
 
http://127.0.0.1:8080/listCategory?start=2
 
重启测试访问
下载地址： http://download.how2j.cn/1655/springboot.rar
 

posted on 2019-01-04 16:14  我是司  阅读(726)  评论(0)    收藏  举报

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