【DRP】——图片上传（第一种）

爱被打了一巴掌 2022-06-14 05:42 155阅读 0赞

# 前言 #

最近在学习DRP，其中有一个功能是实现对物料信息图片上传的功能

![Center][]

# 功能实现 #

##    1.引入jar包 ##

![Center 1][]

##     2.Servlet ##

FileUploadServlet.java

package com.bjpowernode.drp.basedata.web;
    
    import java.io.File;
    import java.io.IOException;
    import java.io.PrintWriter;
    import java.util.Iterator;
    import java.util.List;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.apache.commons.fileupload.FileItem;
    import org.apache.commons.fileupload.FileUploadException;
    import org.apache.commons.fileupload.disk.DiskFileItemFactory;
    import org.apache.commons.fileupload.servlet.ServletFileUpload;
    
    public class FileUploadServlet extends HttpServlet {
    
    //	private String uploadPath = "D:\\DRP\\apache-tomcat-7.0.75\\webapps\\drp4.0\\upload\\"; // 用于存放上传文件的目录
    	private File uploadPath;
    //	private File tempPath = new File("D:\\addnetFile\\tmp\\"); // 用于存放临时文件的目录
    	private File tempPath;
    	
    	public void doPost(HttpServletRequest req, HttpServletResponse res)
    			throws ServletException, IOException {
    		//multipart/form-data
    //		String itemNo = req.getParameter("itemNo");
    //		System.out.println("itemNo======" + itemNo);
    		DiskFileItemFactory factory = new DiskFileItemFactory();
    		// maximum size that will be stored in memory
    		factory.setSizeThreshold(4096);
    		// the location for saving data that is larger than getSizeThreshold()
    		factory.setRepository(tempPath);
    
    		ServletFileUpload upload = new ServletFileUpload(factory);
    		// maximum size before a FileUploadException will be thrown
    		upload.setSizeMax(1000000 * 20);
    		try {
    			List fileItems = upload.parseRequest(req);	
    			String itemNo ="";
    			for(Iterator iter = fileItems.iterator(); iter.hasNext();){			
    				FileItem item = (FileItem) iter.next();
    				//是普通的表单输入域
    				if(item.isFormField()){
    					if("itemNo".equals(item.getFieldName())){
    						itemNo = item.getString();
    					}
    				}
    				// 是否為input="type"输入域
    				if (!item.isFormField()) {
    					String fileName = item.getName();
    					long size = item.getSize();
    					if ((fileName == null || fileName.equals("")) && size == 0){
    						continue;	
    					}
    					//截取字符串 C:\Users\sms\Desktop\1.txt
    					fileName= fileName.substring(fileName.lastIndexOf("\\") + 1, fileName.length()); 
    //					item.write(new File(uploadPath + itemNo + ".jpg"));
    					item.write(new File(uploadPath,  itemNo + ".jpg"));	
    				} 
    			}
    			res.sendRedirect(req.getContextPath() + "/servlet/item/SearchItemServlet");
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    
    	}
    
    	public void init() throws ServletException {
    		  uploadPath= new File(getServletContext().getRealPath("upload"));
    		  System.out.println("uploadPath=====" + uploadPath);
    		  //如果目录不存在
    		  if(!uploadPath.exists()){
    			  //创建目录
    			  uploadPath.mkdir();
    		  }
    		  tempPath=new File(getServletContext().getRealPath("temp"));
    		  if(!tempPath.exists()){
    			  tempPath.mkdir();
    		  }
    	}
    
    }

ShowItemUploadServlet

package com.bjpowernode.drp.basedata.web;
    
    import java.io.IOException;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import com.bjpowernode.drp.basedata.domain.Item;
    import com.bjpowernode.drp.basedata.manager.ItemManager;
    import com.bjpowernode.drp.basedata.manager.ItemManagerImpl;
    
    /**
     * @author sms
     *
     */
    public class ShowItemUploadServlet extends HttpServlet {
    
    	private ItemManager itemManager;
    	
    	@Override
    	public void init() throws ServletException {
    		itemManager = new ItemManagerImpl();
    	}
    	
    	@Override
    	protected void doGet(HttpServletRequest request, HttpServletResponse response)
    			throws ServletException, IOException {
    		doPost(request,response);
    	}
    
    	@Override
    	protected void doPost(HttpServletRequest request, HttpServletResponse response)
    			throws ServletException, IOException {
    		String itemNo = request.getParameter("itemNo");
    		Item item = itemManager.findItemById(itemNo);
    		request.setAttribute("item", item);
    		
    		request.getRequestDispatcher("/basedata/item_upload.jsp").forward(request, response);
    	}
    
    }

##   3.配置文件web.xml ##

<servlet>
    		<servlet-name>FileUploadServlet</servlet-name>
    		<servlet-class>com.bjpowernode.drp.basedata.web.FileUploadServlet</servlet-class>
    		<load-on-startup>10</load-on-startup>
    	</servlet>
    	
    	<servlet-mapping>
    		<servlet-name>FileUploadServlet</servlet-name>
    		<url-pattern>/servlet/item/FileUploadServlet</url-pattern>
    	</servlet-mapping>
    	
    	<servlet>
    		<servlet-name>ShowItemUploadServlet</servlet-name>
    		<servlet-class>com.bjpowernode.drp.basedata.web.ShowItemUploadServlet</servlet-class>
    	</servlet>
    	
    	<servlet-mapping>
    		<servlet-name>ShowItemUploadServlet</servlet-name>
    		<url-pattern>/servlet/item/ShowItemUploadServlet</url-pattern>
    	</servlet-mapping>

##     4.item\_upload.jsp ##

<tr>
     <td height="74">
     <div align="right">
     图片:  
     </div>
     </td>
     <td>
     <img src="upload/<%=item.getItemNo()%>.jpg" width="85" height="49">
     </td>
    </tr>

# 总结 #

这种方式是有不足之处的，下篇写另一种方法。

[Center]: /images/20220614/5de10d73dd5b4861b0303ee18fdb4f40.png
[Center 1]: /images/20220614/ba6f260810d847a08f395b7befc6c75e.png