Java中实现文件上传下载的三种解决方案(推荐)

FormFile file=manform.getFile(); String newfileName = null;String newpathname=null;String fileAddre="/numUp";try {InputStream stream = file.getInputStream();// 把文件读入String filePath = request.getRealPath(fileAddre);//取系统当前路径File file1 = new File(filePath);//添加了自动创建目录的功能((File) file1).mkdir(); newfileName = System.currentTimeMillis()+ file.getFileName().substring(file.getFileName().lastIndexOf('.'));ByteArrayOutputStream baos = new ByteArrayOutputStream();OutputStream bos = new FileOutputStream(filePath + "/"+ newfileName);newpathname=filePath+"/"+newfileName;System.out.println(newpathname);// 建立一个上传文件的输出流System.out.println(filePath+"/"+file.getFileName());int bytesRead = 0;byte[] buffer = new byte[8192];while ((bytesRead = stream.read(buffer, 0, 8192)) != -1) {bos.write(buffer, 0, bytesRead);// 将文件写入服务器}bos.close();stream.close();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}

package com.vogoal.util;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Date;import java.util.Hashtable;import javax.servlet.ServletInputStream;import javax.servlet.http.HttpServletRequest;public class JspFileUpload {/** request对象 */private HttpServletRequest request = null;/** 上传文件的路径 */private String uploadPath = null;/** 每次读取得字节的大小 */private static int BUFSIZE = 1024 * 8;/** 存储参数的Hashtable */private Hashtable paramHt = new Hasptable();/** 存储上传的文件的文件名的ArrayList */private ArrayList updFileArr = new ArrayList();/*** 设定request对象。* * @param request* HttpServletRequest request对象*/public void setRequest(HttpServletRequest request) {this.request = request;}/*** 设定文件上传路径。* * @param path* 用户指定的文件的上传路径。*/public void setUploadPath(String path) {this.uploadPath = path;}/*** 文件上传处理主程序。�������B* * @return int 操作结果 0 文件操作成功；1 request对象不存在。 2 没有设定文件保存路径或者文件保存路径不正确；3* 没有设定正确的enctype；4 文件操作异常。*/public int process() {int status = 0;// 文件上传前，对request对象，上传路径以及enctype进行check。status = preCheck();// 出错的时候返回错误代码。if (status != 0)return status;try {// ��参数或者文件名�u��String name = null;// 参数的valueString value = null;// 读取的流是否为文件的标志位boolean fileFlag = false;// 要存储的文件。File tmpFile = null;// 上传的文件的名字String fName = null;FileOutputStream baos = null;BufferedOutputStream bos = null;// ��存储参数的HashtableparamHt = new Hashtable();updFileArr = new ArrayList();int rtnPos = 0;byte[] buffs = new byte[BUFSIZE * 8];// �取得ContentTypeString contentType = request.getContentType();int index = contentType.indexOf("boundary=");String boundary = "--" + contentType.substring(index + 9);String endBoundary = boundary + "--";// �从request对象中取得流。ServletInputStream sis = request.getInputStream();// 读取1行while ((rtnPos = sis.readLine(buffs, 0, buffs.length)) != -1) {String strBuff = new String(buffs, 0, rtnPos);// 读取1行数据�n��if (strBuff.startsWith(boundary)) {if (name != null && name.trim().length() > 0) {if (fileFlag) {bos.flush();baos.close();bos.close();baos = null;bos = null;updFileArr.add(fName);} else {Object obj = paramHt.get(name);ArrayList al = new ArrayList();if (obj != null) {al = (ArrayList) obj;}al.add(value);System.out.println(value);paramHt.put(name, al);}}name = new String();value = new String();fileFlag = false;fName = new String();rtnPos = sis.readLine(buffs, 0, buffs.length);if (rtnPos != -1) {strBuff = new String(buffs, 0, rtnPos);if (strBuff.toLowerCase().startsWith("content-disposition: form-data; ")) {int nIndex = strBuff.toLowerCase().indexOf("name=/"");int nLastIndex = strBuff.toLowerCase().indexOf("/"", nIndex + 6);name = strBuff.substring(nIndex + 6, nLastIndex);}int fIndex = strBuff.toLowerCase().indexOf("filename=/"");if (fIndex != -1) {fileFlag = true;int fLastIndex = strBuff.toLowerCase().indexOf("/"", fIndex + 10);fName = strBuff.substring(fIndex + 10, fLastIndex);fName = getFileName(fName);if (fName == null || fName.trim().length() == 0) {fileFlag = false;sis.readLine(buffs, 0, buffs.length);sis.readLine(buffs, 0, buffs.length);sis.readLine(buffs, 0, buffs.length);continue;}else{fName = getFileNameByTime(fName);sis.readLine(buffs, 0, buffs.length);sis.readLine(buffs, 0, buffs.length);}}}} else if (strBuff.startsWith(endBoundary)) {if (name != null && name.trim().length() > 0) {if (fileFlag) {bos.flush();baos.close();bos.close();baos = null;bos = null;updFileArr.add(fName);} else {Object obj = paramHt.get(name);ArrayList al = new ArrayList();if (obj != null) {al = (ArrayList) obj;}al.add(value);paramHt.put(name, al);}}} else {if (fileFlag) {if (baos == null && bos == null) {tmpFile = new File(uploadPath + fName);baos = new FileOutputStream(tmpFile);bos = new BufferedOutputStream(baos);}bos.write(buffs, 0, rtnPos);baos.flush();} else {System.out.println("test :" + value + "--" + strBuff);value = value + strBuff;}}}} catch (IOException e) {status = 4;}return status;}private int preCheck() {int errCode = 0;if ( request == null )return 1;if ( uploadPath == null || uploadPath.trim().length() == 0 )return 2;else{File tmpF = new File(uploadPath);if (!tmpF.exists())return 2;}String contentType = request.getContentType();if ( contentType.indexOf("multipart/form-data") == -1 )return 3;return errCode;}public String getParameter(String name){String value = "";if ( name == null || name.trim().length() == 0 )return value;value = (paramHt.get(name) == null)?"":(String)((ArrayList)paramHt.get(name)).get(0);return value;}public String[] getParameters(String name){if ( name == null || name.trim().length() == 0 )return null;if ( paramHt.get(name) == null )return null;ArrayList al = (ArrayList)paramHt.get(name);String[] strArr = new String[al.size()];for ( int i=0;i<al.size();i++ )strArr[i] = (String)al.get(i);return strArr;}public int getUpdFileSize(){return updFileArr.size();}public String[] getUpdFileNames(){String[] strArr = new String[updFileArr.size()];for ( int i=0;i<updFileArr.size();i++ )strArr[i] = (String)updFileArr.get(i);return strArr;}private String getFileName(String input){int fIndex = input.lastIndexOf("//");if (fIndex == -1) {fIndex = input.lastIndexOf("/");if (fIndex == -1) {return input;}} input = input.substring(fIndex + 1);return input;}private String getFileNameByTime(String input){int index = input.indexOf(".");Date dt = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmssSSS");return input.substring(0,index) + sdf.format(dt) + input.substring(index);}}

<%@page import="com.vogoal.util.JspFileUpload"%><%//初始化JspFileUpload jfu = new JspFileUpload();//设定request对象jfu.setRequest(request);//设定上传的文件路径jfu.setUploadPath("C://");//上传处理int rtn = jfu.process();//取得form中其他input控件参数的值String username = jfu.getParameter("username");//如果对应同一个参数有多个input控件，返回数组String[] usernameArr = jfu.getParameters("username");//取得上传的文件的名字String[] fileArr = jfu.getUpdFileNames();//取得上传文件的个数，这个方法有点鸡肋int fileNumber = jfu.getUpdFileSize();//下面的是测试输出的代码。// out.println("parameter:" + username);// out.println("parameter size:" + usernameArr.length);// out.println("fileArr size:" + fileArr.length);// if (fileArr.length > 0)// out.println("fileArr 0:" + fileArr[0]);%>

public class UploadAction{ private File uploadImage; //文件 private String uploadImageContentType;//文件的类型 private String uploadImageFileName;//文件的名称 private String bookname;//书名 private String author;//作者 private String savePath;//文件的保存位置 //属性的getter/setter方法 public String upload() throws Exception{ //实现上传代码，I/O操作完成 return "uploadSuccess"; } } 

<action name="upload" class="com.gqy.UploadAction"> <param name="savePath">/uploadFile</param> <result>/success.jsp</result> </action> 

<param name="allowTypes"> image/bmp,image/png,image/gif,image/jpeg </param> 

<param name="maximumSize" >1048576</param> 

<action name="uploadFileAction" class="com.actions.UploadFileAction"> <interceptor-ref name="defaultStack"> <!-- 配置允许上传的文件类型，多个用","分隔 --> <param name="fileUpload.allowedTypes"> image/bmp,image/png,image/gif,image/jpeg,image/jpg ,image/x-png, image/pjpeg </param> <!-- 配置允许上传的文件大小，单位字节,本例为：1MB --> <param name="fileUpload.maximumSize">1048576</param> </interceptor-ref> <result name="input">/jsp/oneFileFileupload.jsp</result> <result name="success">/jsp/result.jsp</result> </action> 

<constant name="struts.custom.i18n.resources" value="messages"/>或<constant name="struts.custom.i18n.resources" value="messages_zh_CN"/>

public class FileDownloadAction implements Action{ //该属性值在配置文件中指定，Struts2会自动进行注入（即赋值），需要为该属性提供setter和 getter方法 private String inputPath;//指定要下载的文件的完整路径(路径名＋文件名) /* * 实现下载的Action类应该提供一个返回InputStream实例的方法，该方法对应在 <result.../>里的inputName属性值为targetFile */ public InputStream getTargetFile() throws Exception{ return ServletActionContext.getServletContext().getResourceAsStream(inputPath); } //处理用户请求的execute方法，该方法返回success字符串 public String execute() throws Exception{ return "success"; } } 

<action name="download" class="com.FileDownloadAction"><!--指定被下载资源的位置--><param name="inputPath">/uploadFile/demo.txt</param><!--配置结果类型为stream的结果--><result name="success" type="stream"><!--指定下载文件的文件类型--><param name="contentType"></param><!--指定下载文件的文件位置--><param name="inputName">targetFile</param><!--指定下载文件的下载方式及下载时的保存文件名，filename保存时的文件名必须有扩展名，扩展名指示了下载类型的图标--><param name="contentDisposition">attachment;filename=Struts2.txt</param><!--指定下载文件的缓冲区大小--><param name="bufferSize">4096</param></result></action>