jsp文件的上传和下载操作代码

jsp文件上传和下载
package net.jspcn.tool;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
*
* Title: 文件上传类
* Description: 既能对文件进行上传,又能取得输入框的值,最多可同时上传255个文件
* Copyright: Copyright (c) 2002
* Company: Tekson
* @author 莫琼
* @version 1.0
*/
public class UploadBean {
private String[] sourceFile = new String[255]; //源文件名
private String[] suffix = new String[255]; //文件后缀名
private String canSuffix = ".gif.jpg.jpeg.png"; //可上传的文件后缀名
private String objectPath = "c:/"; //目标文件目录
private String[] objectFileName = new String[255]; //目标文件名
private ServletInputStream sis = null; //输入流
private String[] description = new String[255]; //描述状态
private long size = 100 * 1024; //限制大小
private int count = 0; //已传输文件数目
private byte[] b = new byte[4096]; //字节流存放数组
private boolean successful = true;
private Hashtable fields = new Hashtable();
public UploadBean() {
}
//设置上传文件的后缀名
public void setSuffix(String canSuffix) {
this.canSuffix = canSuffix;
}
//设置文件保存路径
public void setObjectPath(String objectPath) {
this.objectPath = objectPath;
}
//设置文件保存路径
public void setSize(long maxSize) {
this.size = maxSize;
}
//文件上传处理程序
public void setSourceFile(HttpServletRequest request) throws IOException {
sis = request.getInputStream();
int a = 0;
int k = 0;
String s = "";
while ( (a = sis.readLine(b, 0, b.length)) != -1) {
s = new String(b, 0, a);
if ( (k = s.indexOf("filename=\"")) != -1) {
// 取得文件数据
s = s.substring(k + 10);
k = s.indexOf("\"");
s = s.substring(0, k);
sourceFile[count] = s;
k = s.lastIndexOf(".");
suffix[count] = s.substring(k + 1);
if (canTransfer(count)) {
transferFile(count);
}
++count;
} else if ( (k = s.indexOf("name=\"")) != -1) {
// 普通表单输入元素，获取输入元素名字
String fieldName = s.substring(k+6, s.length()-3);
sis.readLine(b, 0, b.length);