SSM 类别增加

页面中的增加分类部分

<div class="panel panel-warning addDiv">
     <div class="panel-heading">新增分类</div>
     <div class="panel-body">
         <form method="post" id="addForm" action="admin_category_add" enctype="multipart/form-data">
             <table class="addTable">
                 <tr>
                     <td>分类名称</td>
                     <td><input  id="name" name="name" type="text" class="form-control"></td>
                 </tr>
                 <tr>
                     <td>分类圖片</td>
                     <td>
                         <input id="categoryPic" accept="image/*" type="file" name="image" />
                     </td>
                 </tr>
                 <tr class="submitTR">
                     <td colspan="2" align="center">
                         <button type="submit" class="btn btn-success">提 交</button>
                     </td>
                 </tr>
             </table>
         </form>
     </div>

为空判断

<script>
$(function(){
     
    $("#addForm").submit(function(){
        if(!checkEmpty("name","分类名称"))
            return false;
        if(!checkEmpty("categoryPic","分类图片"))
            return false;
        return true;
    });
});
 
</script>

在CategoryMapper.xml中新增加 插入分类的SQL语句

需要加上2个属性：keyProperty=”id” useGeneratedKeys=”true” 以确保Category对象通过mybatis增加到数据库之后得到的id增长值会被设置在Category对象上。 因为在保存分类图片的时候需要用到这个id值，所以这一步是必须的。

<?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">
 
<mapper namespace="com.how2java.tmall.mapper.CategoryMapper">
    <select id="list" resultType="Category">
        select * from   category         order by id desc
        <if test="start!=null and count!=null">
            limit #{start},#{count}
        </if>
 
    </select>
    <select id="total" resultType="int">
        select count(*) from category
    </select>
    <insert id="add"  keyProperty="id"  useGeneratedKeys="true" parameterType="Category" >
        insert into category ( name ) values (#{name})
    </insert>
</mapper>

在CategoryMapper中新增add方法

import java.util.List;
  
public interface CategoryMapper {
     List<Category> list(Page page);
 
     int total();
 
     void add(Category category);
}

CategoryService

import java.util.List;
 
public interface CategoryService{
    int total();
    List<Category> list(Page page);
 
    void add(Category category);
 
}

CategoryServiceImpl

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(Page page) {
        return categoryMapper.list(page);
    }
 
    @Override
    public int total() {
        return categoryMapper.total();
    }
 
    @Override
    public void add(Category category) {
        categoryMapper.add(category);
    }
}

新增UploadedImageFile ，其中有一个MultipartFile 类型的属性，用于接受上传文件的注入

属性名称image必须和页面中的增加分类部分中的type=”file”的name值保持一致

import org.springframework.web.multipart.MultipartFile;
  
public class UploadedImageFile {
    MultipartFile image;
  
    public MultipartFile getImage() {
        return image;
    }
  
    public void setImage(MultipartFile image) {
        this.image = image;
    }
  
}

ImageUtil 工具类

• change2jpg 确保图片文件的二进制格式是jpg。
• resizeImage用于改变图片大小，在上传产品图片的时候会用到。

import java.awt.Image;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferInt;
import java.awt.image.DirectColorModel;
import java.awt.image.PixelGrabber;
import java.awt.image.Raster;
import java.awt.image.RenderedImage;
import java.awt.image.WritableRaster;
import java.io.File;
import java.io.IOException;
  
import javax.imageio.ImageIO;
  
public class ImageUtil {
  
    public static BufferedImage change2jpg(File f) {
        try {
            Image i = Toolkit.getDefaultToolkit().createImage(f.getAbsolutePath());
            PixelGrabber pg = new PixelGrabber(i, 0, 0, -1, -1, true);
            pg.grabPixels();
            int width = pg.getWidth(), height = pg.getHeight();
            final int[] RGB_MASKS = { 0xFF0000, 0xFF00, 0xFF };
            final ColorModel RGB_OPAQUE = new DirectColorModel(32, RGB_MASKS[0], RGB_MASKS[1], RGB_MASKS[2]);
            DataBuffer buffer = new DataBufferInt((int[]) pg.getPixels(), pg.getWidth() * pg.getHeight());
            WritableRaster raster = Raster.createPackedRaster(buffer, width, height, width, RGB_MASKS, null);
            BufferedImage img = new BufferedImage(RGB_OPAQUE, raster, false, null);
            return img;
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return null;
        }
    }
  
    public static void resizeImage(File srcFile, int width,int height, File destFile) {
        try {
            if(!destFile.getParentFile().exists())
                destFile.getParentFile().mkdirs();
            Image i = ImageIO.read(srcFile);
            i = resizeImage(i, width, height);
            ImageIO.write((RenderedImage) i, "jpg", destFile);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
      
    public static Image resizeImage(Image srcImage, int width, int height) {
        try {
  
            BufferedImage buffImg = null;
            buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            buffImg.getGraphics().drawImage(srcImage.getScaledInstance(width, height, Image.SCALE_SMOOTH), 0, 0, null);
  
            return buffImg;
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }
  
}

CategoryController新增add方法

1. add方法映射路径admin_category_add的访问
2. 通过categoryService保存c对象
3. 通过session获取ControllerContext,再通过getRealPath定位存放分类图片的路径。
   如果严格按照本教程的做法，使用idea中的tomcat部署的话，那么图片就会存放在:E:\project\tmall_ssm\target\tmall_ssm\img\category 这里
4. 根据分类id创建文件名
5. 如果/img/category目录不存在，则创建该目录，否则后续保存浏览器传过来图片，会提示无法保存
6. 通过UploadedImageFile 把浏览器传递过来的图片保存在上述指定的位置
7. 通过ImageUtil.change2jpg(file); 确保图片格式一定是jpg，而不仅仅是后缀名是jpg.
8. 客户端跳转到admin_category_list

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

赏

谢谢你请我吃糖果