jsp如何下载FTP上的文件---ftp协议方式

本人是jsp初学者，费尽好大周折终于实现JSP如何从FTP上下载文件 ，现和大家分享一下，有不对之处请指教。

一、创建java类：

package ftp;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.RandomAccessFile;
import java.util.ArrayList;
import java.util.StringTokenizer;

import sun.net.TelnetInputStream;
import sun.net.TelnetOutputStream;
import sun.net.ftp.FtpClient;

public class FtpFile {

String serverIp = "192.168.12.49";

String serverUser = "admin";

String serverPwd = "admin";

FtpClient aftp;

DataOutputStream outputs;

TelnetInputStream ins;

TelnetOutputStream outs;

int ch;

public String a;

String hostname = "";

private String path = "/";

public FtpClient connect(String RWFileDir, String hostname, int port,
String uid, String pwd) {
/*
* this.hostname = hostname;
* System.out.println("正在连接"+hostname+"，请等待....."); try{ aftp = new
* FtpClient(hostname,port); aftp.login(uid,pwd); aftp.binary();
* //aftp.openPortDataConnection(); a = "连接主机:"+hostname+"成功!";
* System.out.println(a); } catch(FtpLoginException e){
* a="登陆主机:"+hostname+"失败!请检查用户名或密码是否正确："+e; System.out.println(a);
* //return false; } catch (IOException e){
* a="连接主机:"+hostname+"失败!请检查端口是否正确："+e; System.out.println(a); //return
* false; } catch(SecurityException e) {
* a="无权限与主机:"+hostname+"连接!请检查是否有访问权限："+e; System.out.println(a);
* //return false; }
*/

// log(RWFileDir,a);
FtpClient ftpClient = null;
try {
ftpClient = new FtpClient();
// 创建FtpClient对象
ftpClient.openServer(hostname);
// 连接FTP服务器
ftpClient.login(uid, pwd);
// 登录FTP服务器
aftp = ftpClient;
aftp.cd(RWFileDir);
} catch (IOException ex) {
;
}
return ftpClient;
}

public void stop(String RWFileDir) {
String message = "";
try {
if (aftp != null) {
aftp.closeServer();
message = "与主机" + hostname + "连接已断开!";
System.out.println(message);
//log(RWFileDir, message);
}
} catch (IOException e) {
message = "与主机" + hostname + "断开连接失败!" + e;
System.out.println(message);
log(RWFileDir, message);
}
}

public void showFileContents(String strdir) {
StringBuffer buf = new StringBuffer();
try {
aftp.cd(strdir);
ins = aftp.list();
while ((ch = ins.read()) >= 0) {
buf.append((char) ch);
}

System.out.println("buf-------------" + buf.toString());
ins.close();
} catch (IOException e) {
}
}

// 返回当前目录的所有文件及文件夹
public ArrayList getFileList() throws IOException {

BufferedReader dr = new BufferedReader(new InputStreamReader(aftp
.list()));
ArrayList a1 = new ArrayList(); // 存放文件
// ArrayList a2= new ArrayList(); //存放文件夹
ArrayList a3 = new ArrayList(); // 存放文件夹详细资料
// ArrayList a4= new ArrayList(); //存放文件夹下其它文件夹下的文件
ArrayList a5 = new ArrayList(); // 存放文件夹下其它文件夹下的文件
String s = "";
// Hashtable ha=new Hashtable();
// ha=null;

while ((s = dr.readLine()) != null) {

if (isFile(s)) {
// a4.clear();
// a4.remove(0);
// a4=null;
ArrayList a4 = new ArrayList(); // 存放文件夹下其它文件夹下的文件
a4.add(parseLine(s).get(8).toString());

a4.add("文件");
a4.add(parseLine(s).get(4).toString() + "bytes");
a3.add(a4);

}

else if (isDir(s)) {
// a2.add(parseLine(s).get(8));
// showFileContents(s);
// a3.add(parseLine(s));
// System.out.println("ssssssss:"+s);
// a4.add(getNameList(s));
// a2.clear();
// a2.remove(0);
// a2=null;

String tem = parseLine(s).get(8).toString();

if ((tem.trim().equals(".")) || (tem.trim().equals(".."))) {
} else {
ArrayList a2 = new ArrayList(); // 存放文件夹
a2.add(parseLine(s).get(8).toString());
// a2.add("nbsp;");
a2.add("文件夹");
a2.add(parseLine(s).get(4).toString() + "bytes");
a1.add(a2);

}
}

// a1.add(parseLine(s).get(8));
// a1.add(s);
// System.out.println("xxxxxxxxxxxxxxxxx:"+parseLine(s).get(8));
// a1.addAll(a2);

}
a5.add(a1);
a5.add(a3);
dr.close();
aftp.closeServer();

return a5;
}

public void setPath(String path) throws IOException {
if (aftp == null)
this.path = path;
else {
aftp.cd(path);
}
}

// 返回当前目录的文件名称
public ArrayList getNameList(String RWFileDir) throws IOException {

// System.out.println("xxxxxxx--------------111111111");
BufferedReader dr = new BufferedReader(new InputStreamReader(aftp
.nameList(RWFileDir)));
// System.out.println("xxxxxxx---------------22222222222");
// System.out.println(dr.readLine().toString()+"ddddddddd");
ArrayList al = new ArrayList();
String s = "";
int j = 0;
while ((s = dr.readLine()) != null) {
System.out.println(s);
al.add(s);
j++;
// s = s.substring(13,s.length());
isFile(s);
// downloadFile(RWFileDir,s);
// String strFileDelF = aftp.nameList("subunsubtosp\\");
// File fileDelF=new File(s);
// fileDelF.delete();
}
System.out.println("xxxxxxxxxxxx" + j);
return al;
// System.out.println(al.add(s));
}

// 判断一行文件信息是否为目录
public boolean isDir(String line) {
return ((String) parseLine(line).get(0)).indexOf("d") != -1;
}

public boolean isFile(String line) {
return !isDir(line);
}

// 处理getFileList取得的行信息
private ArrayList parseLine(String line) {
ArrayList s1 = new ArrayList();
StringTokenizer st = new StringTokenizer(line, " ");
while (st.hasMoreTokens()) {
s1.add(st.nextToken());
}
return s1;
}

// 写消息日志
public static void log(String RWFileDir, String msg) {
String message = "";
try {
java.text.DateFormat df = new java.text.SimpleDateFormat(
"yyyy-MM-dd HH:mm:ss");
java.text.DateFormat dflog = new java.text.SimpleDateFormat(
"yyyyMMdd");
java.util.Date date = new java.util.Date();
String datestr = df.format(new java.util.Date());
String datelog = dflog.format(new java.util.Date());
// String datelog = datestr.substring(0,10);
// datelog = datelog.replace('-',' ');
// 按日期每天生成一个日志文件
FileWriter fwl = new FileWriter(RWFileDir + "CMSSftp" + datelog
+ ".log", true);
PrintWriter outl = new PrintWriter(fwl);
outl.println(datestr + " " + msg);
outl.close();
fwl.close();
} catch (IOException e) {
message = "写log文件错误!" + e;
e.printStackTrace();
log(RWFileDir, message);
System.out.println(message);
}
}

}
二、创建main.jsp页面下载文件，链接彩用ftp://用户名：密码：@IP/目录名/文件名 形式：

<%@ page language="java" contentType="text/html; charset=GB2312"%>
<%@ page import="ftp.*"%>
<%@ page import="java.util.ArrayList;"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>FTP下载主页面</title>
<meta content="text/html; charset=gb2312" http-equiv="Content-Type">
<link rel="stylesheet" type="text/css" href="css/list.css">
</head>
<body>
<form id='list' name='list' action='post'>
<%
/*
*FTP文件列表功能：从FTP上列出存在的目录及文件
*FTP文件下载功能：从FTP上下载相应的文件
*/
String server = "192.168.12.49"; // 输入的FTP服务器的IP地址
String user = "admin"; // 登录FTP服务器的用户名
String password = "admin"; // 登录FTP服务器的用户名的口令
String path = request.getParameter("path");
if ((path == null) || (path.length() < 1)) {
path = "/";
} else {
path = new String(path.getBytes("ISO-8859-1"), "GBK"); //防止出现乱码
}

ArrayList arr = new ArrayList(); //用于存放根目录下的目录list和文件list
ArrayList arr1 = new ArrayList(); //用于存放根目录下的目录list
ArrayList arr2 = new ArrayList(); //用于存放根目录下的文件list
ArrayList arr3 = new ArrayList(); //临时list,用于存放目录名和文件名

FtpFile ft = null;

try {
ft = new FtpFile();
ft.connect(path, server, 21, user, password);
arr = ft.getFileList(); //获取根目录文件夹列表
} catch (Exception ex) {
System.out.println(ex.toString());

}
arr1 = (ArrayList) arr.get(0);
arr2 = (ArrayList) arr.get(1);
out
.print("<font size='4'><center><b>FTP 文 件 列 表</b></center></font><br>");
out.print("<table style='width:80%' align='center'><tr>");

out.print("<td align='left'><font size='2' color='red'>*当前位置："
+ path + "</font></td>");

out
.print("<td align='right'><input type='button' align='right' value='返回上一页' onClick='history.go(-1)'></td>");
out
.println("<table border=0 cellPadding='5' cellSpacing='2' class='listtable' align='center' style='width:80%'><tr class='firstline'><td width='200px'align='center'>文件名</td><td width='60px' align='center'>类型</td><td width='100' align='center'>大小</td><td align='center'>下载</td></tr>");

for (int i = 0; i < arr1.size(); i++) { //取出文件夹

arr3 = (ArrayList) arr1.get(i);
out.print("<tr class='line'>");
for (int j = 0; j < arr3.size(); j++) {
out.print("<td><B>");
String tempstr = arr3.get(j).toString();
if (j == 0) {
if (path.length() > 1) {
out.print("<a href='main.jsp?path=" + path + "/"
+ tempstr + "'>" + tempstr + "</a>");
} else {
out.print("<a href='main.jsp?path=" + path
+ tempstr + "'>" + tempstr + "</a>");
}

} else {
out.print(tempstr);
}
out.print("</B></td>");
}
out.print("<td> </td></tr>");

}
String filename = null;
for (int i = 0; i < arr2.size(); i++) { //取出文件
arr3 = (ArrayList) arr2.get(i);
out.print("<tr class='line'>");
for (int j = 0; j < arr3.size(); j++) {
out.print("<td>");

String tempstr = arr3.get(j).toString();
if (j == 0) {
filename = tempstr;
if (path.trim().length() > 1) { //如果path带有下级有子文件
out.print("<a href='ftp://" + user + ":" + password
+ "@" + server + path + "/" + filename
+ "'>" + tempstr + "</a>");
} else { //path只是根目录
out.print("<a href='ftp://" + user + ":" + password
+ "@" + server + path + filename + "'>"
+ tempstr + "</a>");
}
} else {
out.print(tempstr);
}
out.print("</td>");
}
if (path.trim().length() > 1) { //如果path带有下级有子文件
out
.print("<td width='100px' align='center'><a href='ftp://"
+ user
+ ":"
+ password
+ "@"
+ server
+ path
+ "/"
+ filename
+ "'>下载</a></td></tr>");
} else { //path只是根目录
out
.print("<td width='100px' align='center'><a href='ftp://"
+ user
+ ":"
+ password
+ "@"
+ server
+ path + filename + "'>下 载</a></td></tr>");
}
}
out.print("</table>");
ft.stop(path);
ft = null;
%>
</form>
</body>
</html>