fileupload上传文件

最新推荐文章于 2025-12-01 13:49:36 发布

最新推荐文章于 2025-12-01 13:49:36 发布 · 72 阅读

文章标签：

#java

本文介绍了一个基于Apache Commons FileUpload库的Java文件上传示例。通过Servlet处理文件上传请求，并设置了临时文件目录、缓存大小及文件大小限制。

FileUpload 是 Apache commons下面的一个子项目，用来实现Java环境下面的文件上传功能，

commons- fileupload-1.2.1：http://l7.yunpan.cn/lk/Qv7QNNd7KJjFM

依赖于

commons-io-1.4：http://l7.yunpan.cn/lk/Qv7Qpp3qapF9A

demo参考

package com.sunflower.servlet;

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

public class FileUpload extends HttpServlet {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	//Post方法
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		//设置编码
		req.setCharacterEncoding("UTF-8");
		//文件上传处理
		fileControl(req, resp);
	}

	/**
	 * 上传文件的处理
	 */
	private void fileControl(HttpServletRequest req, HttpServletResponse resp) throws ServletException {

		// 在解析请求之前先判断请求类型是否为文件上传类型
//		boolean isMultipart = ServletFileUpload.isMultipartContent(req);

		// 文件上传处理工厂
		FileItemFactory factory = new DiskFileItemFactory();
		
		//创建临时文件目录
//		File tempFile = new File(req.getRealPath("/temp"));
		File tempFile = new File(this.getServletContext().getRealPath("/temp"));
		//设置缓存大小
		((DiskFileItemFactory) factory).setSizeThreshold(1024*1024);
		//设置临时文件存放地点
		((DiskFileItemFactory) factory).setRepository(tempFile);

		// 创建文件上传处理器
		ServletFileUpload upload = new ServletFileUpload(factory);
		//将页面请求传递信息最大值设置为50M
		upload.setSizeMax(1024*1024*50);
		//将单个上传文件信息最大值设置为6M
		upload.setFileSizeMax(1024*1024*12);
		
		

		// 开始解析请求信息
		List items = null;
		try {
			items = upload.parseRequest(req);
		}
		catch (FileUploadException e) {
			e.printStackTrace();
		}

		// 对所有请求信息进行判断
		Iterator iter = items.iterator();
		while (iter.hasNext()) {
			FileItem item = (FileItem) iter.next();
			// 信息为普通的格式
			if (item.isFormField()) {
				String fieldName = item.getFieldName();
				String value = item.getString();
				System.out.println("formfile文件名为："+fieldName+"值："+value);
				
				req.setAttribute(fieldName, value);
			}
			// 信息为文件格式
			else {
				long d =item.getSize();
				if(d>upload.getSizeMax()){
					try {
						resp.sendRedirect("/index");
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
				String fileName = item.getName();
				System.out.println("upload_file文件名为："+fileName);
				int index = fileName.lastIndexOf("\\");
				fileName = fileName.substring(index+1 );
				System.out.println("upload_file文件名为："+fileName);
				
				System.out.println("文件大小"+d);
				req.setAttribute("realFileName", fileName);

				//写进文件
				String basePath = this.getServletContext().getRealPath("/uploadFile");	
				System.out.println("basePath  is :  "+basePath);
				
				File file = new File(basePath, fileName);
				try {
					item.write(file);
					System.out.println("写入成功！");
				}
				catch (Exception e) {
					e.printStackTrace();
				}
			}
		}

//		try {
//			req.getRequestDispatcher("/download.jsp").forward(req, resp);
//		}
//		catch (IOException e) {
//			e.printStackTrace();
//		}
	}
}