【Spring+Mybatis+SpringMVC整合项目四】天猫商城（后台-分类管理开发）

在完成前面的准备工作之后，开始对业务进行开发了，首先从后台的分类管理开始进行开发，后台的模块可以分为下图几点

当我们访问后台的首页时

是直接去访问admin_category_list,这是请求会被SpringMVC拦截到，由DispatcherServlet去分发请求，这时就会去到CategoryController下并执行list（）方法

CategoryController类如下

package com.how2java.tmall.controller;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.how2java.tmall.pojo.Category;
import com.how2java.tmall.service.CategoryService;
import com.how2java.tmall.util.ImageUtil;
import com.how2java.tmall.util.Page;
import com.how2java.tmall.util.UploadedImageFile;
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.multipart.MultipartFile;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpSession;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.List;

@Controller
@RequestMapping("")
public class CategoryController {
    @Autowired
    CategoryService categoryService;

    @RequestMapping("admin_category_list")
    public String list(Model model,Page page){
        PageHelper.offsetPage(page.getStart(),page.getCount());
        List<Category> cs= categoryService.list();
        int total=(int) new PageInfo<>(cs).getTotal();
        page.setTotal(total);
        model.addAttribute("cs", cs);
        model.addAttribute("page", page);
        return "admin/listCategory";
    }

    @RequestMapping("admin_category_add")
    public String add(Category c, HttpSession session, UploadedImageFile uploadedImageFile) throws IOException {
        System.out.println(c.getId());
        categoryService.add(c);
        System.out.println(c.getId());
        File  imageFolder= new File(session.getServletContext().getRealPath("img/category"));
        File file = new File(imageFolder,c.getId()+".jpg");
        if(!file.getParentFile().exists())
            file.getParentFile().mkdirs();
        System.out.println(uploadedImageFile);
        System.out.println(uploadedImageFile.getImage());
        System.out.println(file);
        uploadedImageFile.getImage().transferTo(file);
        BufferedImage img = ImageUtil.change2jpg(file);
        ImageIO.write(img, "jpg", file);

        return "redirect:/admin_category_list";
    }

    @RequestMapping("admin_category_delete")
    public String delete(int id,HttpSession session)throws IOException{
        categoryService.delete(id);

        File imageFolder=new File(session.getServletContext().getRealPath("img/category"));
        File file=new File(imageFolder,id+".jpg");
        file.delete();

        return "redirect:/admin_category_list";
    }

    @RequestMapping("admin_category_edit")
    public String edit(int id,Model model){
        Category c=categoryService.get(id);
        model.addAttribute("c",c);
        return "admin/editCategory";
    }
    @RequestMapping("admin_category_update")
    public String update(Category c, HttpSession session, UploadedImageFile uploadedImageFile) throws IOException {
        categoryService.update(c);
        MultipartFile image = uploadedImageFile.getImage();
        if(null!=image &&!image.isEmpty()){
            File  imageFolder= new File(session.getServletContext().getRealPath("img/category"));
            File file = new File(imageFolder,c.getId()+".jpg");
            image.transferTo(file);
            BufferedImage img = ImageUtil.change2jpg(file);
            ImageIO.write(img, "jpg", file);
        }
        return "redirect:/admin_category_list";
    }
}

1.Spring的IOC注入

@Autowired
CategoryService categoryService;

 2.用了mybatis逆向工程，DAO层很多工作Mybatis已经帮我们完成了，直接拿到sevice层就可以使用了

CategoryService提供了一套CURD的操作

package com.how2java.tmall.service;
import com.how2java.tmall.pojo.Category;
import java.util.List;
public interface CategoryService{
    List<Category> list();
    void add(Category category);
    void delete(int id);
    Category get(int id);
    void update(Category category);
}

 CategoryServiceImpl类

package com.how2java.tmall.service.impl;

import com.how2java.tmall.mapper.CategoryMapper;
import com.how2java.tmall.pojo.Category;
import com.how2java.tmall.pojo.CategoryExample;
import com.how2java.tmall.service.CategoryService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class CategoryServiceImpl implements CategoryService {
    @Autowired
    CategoryMapper categoryMapper;

    @Override
    public List<Category> list() {
        CategoryExample example =new CategoryExample();
        example.setOrderByClause("id desc");
        return categoryMapper.selectByExample(example);
    }

    @Override
    public void add(Category category) {
        categoryMapper.insert(category);
    }

    @Override
    public void delete(int id) {
        categoryMapper.deleteByPrimaryKey(id);
    }

    @Override
    public Category get(int id) {
        return categoryMapper.selectByPrimaryKey(id);
    }

    @Override
    public void update(Category category) {
        categoryMapper.updateByPrimaryKeySelective(category);
    }
}

以上就是caegory业务类的实现

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回到list()方法中

@RequestMapping("admin_category_list")
    public String list(Model model,Page page){
        PageHelper.offsetPage(page.getStart(),page.getCount());
        List<Category> cs= categoryService.list();
        int total=(int) new PageInfo<>(cs).getTotal();
        page.setTotal(total);
        model.addAttribute("cs", cs);
        model.addAttribute("page", page);
        return "admin/listCategory";
    }

这里用到了一个开源插件PageHelper，用于分页查询，用categoryService.list()将分类查询出来后，还要查询出分类的总数，用于分页操作，将分类和分页信息放入model中，跳转到listCategort.jsp中

这里因为我们在SpringMVC.xml中配置了视图定位

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass"
                  value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>

prefix意思是前缀，suffix是后缀，那么最后return “admin/listCategory”意思就是

跳转到/WEB-INF/JSP/admin/listCategory.jsp

在listCategory.jsp中用EL表达式将数据去除

listCategory.jsp代码片段

<c:forEach items="${cs}" var="c">
 <tr>
   <td>${c.id}</td>
   <td><img height="40px" src="img/category/${c.id}.jpg"></td>
   <td>${c.name}</td>

   <td><a href="admin_property_list?cid=${c.id}"><span class="glyphicon glyphicon-th-list"></span></a></td>
   <td><a href="admin_product_list?cid=${c.id}"><span class="glyphicon glyphicon-shopping-cart"></span></a></td>
    <td><a href="admin_category_edit?id=${c.id}"><span class="glyphicon glyphicon-edit"></span></a></td>
   <td><a deleteLink="true" href="admin_category_delete?id=${c.id}"><span class="   glyphicon glyphicon-trash"></span></a></td>

    </tr>
</c:forEach>

其他分类管理功能这里就不再多写了，主要是记录一下SSM框架的基本使用