jsp实现文件上传和下载(代码及说明)

特点：1.可以多文件上传；2.返回上传后的文件名；3.form表单中的其他参数也可以得到。

先贴上传类,JspFileUploadpackage 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; /** vogoalAPI 1.0* Auther SinNeR@* by * mail: vogoals@hotm *//*** JSP上传文件类** @author SinNeR* @version 1.0*/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&#65533;n&#65533;&#65533;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(fNam e);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(nam e) == null )return null;ArrayList al = (ArrayList)paramHt.get(nam e); 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 = stIndexOf("\\");if (fIndex == -1) {fIndex = stIndexOf("/");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);}}说明：这个类基本解决了上一贴的上一贴说的存在的bug和不足。