在用struts1.x 或struts2.x 是对与大文件的上传问题

1. 有一些时候可能会用到大文件的上传，但是struts 不支持一些上了几百mb 或几G 的文件

 

在这里我们介绍一个apache 提供的上传文件包

commons-fileupload-1.2.jar

commons-io-1.4.jar

 

实现原理就是先把文件上传到临时文件夹，当上传成功后在写到批定的上传文件夹中

 

package com.test;

import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;

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.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

/**
 * 上传文件servlet 
 * 2008-10-6
 * @author liuqing
 * @version 1.0
 */
public class UploadServlet extends HttpServlet {

	
	/**
	 * 上传文件方法
	 * @param tempDirectory 上传文件 temp 文件夹
	 * @param encoding 上传文件编码
	 * @param uploadDirectory 上传文件目录
	 * @param request 
	 * @return void
	 */
	public void uploadFile(String tempDirectory,
			String encoding,String uploadDirectory,HttpServletRequest request) {
		
		try {
			boolean isMultipart = ServletFileUpload.isMultipartContent(request);
			if (isMultipart) {
				//创建磁工厂，实现内存数据储存量和临时储存路经
				DiskFileItemFactory factory = new DiskFileItemFactory(1024 * 4,
						new File(tempDirectory));
				//设置最多只允许在内存中存储的数据，单位：字节
				factory.setSizeThreshold(1024 * 4);
				ServletFileUpload upload = new ServletFileUpload(factory);
				upload.setHeaderEncoding(encoding);
				upload.setFileSizeMax(1024 * 1024 * 1024 * 5);
				List<FileItem> fileItems = upload.parseRequest(request);
				Iterator<FileItem> iter = fileItems.iterator();
				while (iter.hasNext()) {
					FileItem item = (FileItem)iter.next();
					if (item.isFormField()) {
						String name = item.getFieldName();
						String value = item.getString(encoding);
						System.out.println("" + name + " " + value);
					}
					else {
						String fileName = item.getName();
						if (fileName != null) {
							File fullFile = new File(item.getName());
							if (!this.isTooBig(fullFile.length())) {
								throw new Exception();
							}
							if (fullFile.exists()) {
								File fileOnServer = 
									new File(uploadDirectory + fullFile.getName());
                                item.write(fileOnServer);
							}
						}
					}
				}
			}
		} 
		catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * servlet 上传文件service 方法
	 */
	@Override
	protected void service(HttpServletRequest request, 
			HttpServletResponse response)
			throws ServletException, IOException {
		this.uploadFile("d:\\uploadFile\\temp", "UTF-8", "d:\\uploadFile\\upload\\", request);
		response.sendRedirect("success.jsp");
	}
	/**
	 * 设置文件大小 MB
	 */
	private static int maxSize = 100;
	
	/**
	 * 判断文件大小是否太大
	 * @param argFileSize
	 * @return
	 */
	public boolean isTooBig(long argFileSize) {
		double fileSize = argFileSize / (1024.0 * 1024.0);
		System.out.println("safda" + fileSize);
		return fileSize > maxSize ? false:true;
	}
	
	/**
	 * setter file size
	 * @return int
	 */
	public static void setMaxSize(int maxSize) {
		UploadServlet.maxSize = maxSize;
	}

	
}