利用ftpclient下载文件，解决用window.open打开ftp地址中有中文，不能下载的问题（原创）

我在百度知道里曾提问了本问题，现把我的问题摘录如下：

我现在用JavaScript的window.open('url')，其中url是ftp地址并且地址中含有中文，运行的时候不能下载该ftp地址下的文件，例如：ftp://test:test@10.32.166.144/flashfxp/激活码.txt 但是如果地址是全英文的话就能下载，另外，文件是存在aix系统上，并且系统支持中文。
希望知道是高手赐教下啊!

现在就来看下我解决的代码吧，希望对遇到同样问题的人有点帮助。

1）把ftp地址中的文件保存到本地的java类源码：

package test;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPClientConfig;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;

public class Ftp {

/**?
* Description: 从FTP服务器下载文件?
* @param ip FTP服务器的ip地址?
* @param port FTP服务器端口，默认为：21?
* @param username FTP登录账号?
* @param password FTP登录密码?
* @param remotePath FTP服务器上的相对路径?
* @param fileName 要下载的文件名?
* @param localPath 下载后保存到本地的路径?
* @return?
*/?
public static boolean downFile(String ip, int port,String username, String password, String remotePath,String fileName,String localPath) {???
???? boolean success = false;???
???? FTPClient ftp = new FTPClient();???
???? try {???
???????? int reply;???
?????????ftp.connect(ip, port);
???????? //下面三行代码必须要，而且不能改变编码格式，否则不能正确下载中文文件
?????????ftp.setControlEncoding("GBK");
???????? FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_NT);???
???????? conf.setServerLanguageCode("zh");?
????????
???????? //如果采用默认端口，可以使用ftp.connect(url)的方式直接连接FTP服务器???
?????????ftp.login(username, password);//登录???
???????? reply =?ftp.getReplyCode();???
???????? if (!FTPReply.isPositiveCompletion(reply)) {???
?????????????ftp.disconnect();???
???????????? return success;???
???????? }???
?????????
?????????
?????????ftp.changeWorkingDirectory(remotePath);//转移到FTP服务器目录???
???????? FTPFile[] fs =?ftp.listFiles();???
?????????
???????? for(int i = 0; i < fs.length; i++){?
???????? FTPFile ff = fs[i];
???????????? if(ff.getName().equals(fileName)){???
?????????????
???????????????? File localFile = new File(localPath+File.separator+ff.getName());???
//????????????????????
???????????????? OutputStream is = new FileOutputStream(localFile);???
?????????????????
???????????????? //注意此处retrieveFile的第一个参数由GBK转为ISO-8859-1编码。否则下载后的文件内容为空。
???????????????? //原因可能是由于aix系统默认的编码为ISO-8859-1
?????????????????ftp.retrieveFile(new?String(ff.getName().getBytes("GBK"),"ISO-8859-1"), is);???
???????????????? is.close();???
???????????? }???
???????? }???
????????????
?????????ftp.logout();???
???????? success = true;???
???? } catch (IOException e) {???
???????? e.printStackTrace();???
???? } finally {???
???????? if (ftp.isConnected()) {???
???????????? try {???
?????????????????ftp.disconnect();???
???????????? } catch (IOException ioe) {???
???????????? }???
???????? }???
???? }???
???? return success;???
}

public static void main(String[] args) {
?? // TODO Auto-generated method stub
??Ftp.downFile("10.32.166.144", 21, "test", "test", "/flashfxp", "激活码.txt", "C:");
?? try {
??? String string = new String("激活码".getBytes("utf-8"),"utf-8");
??? System.out.println(string);
?? } catch (UnsupportedEncodingException e) {
??? // TODO Auto-generated catch block
??? e.printStackTrace();
?? }
??
}

}

2）将ftp资源以文件流的方式打开，由用户决定保存在本地何处，程序运行后可以从IE跳出框中打开或者保存的Action代码，利用Struts1写的：

/*
* Generated by MyEclipse Struts
* Template path: templates/java/JavaClass.vtl
*/
package com.mocha.test;

import java.io.IOException;

import java.io.OutputStream;

import java.net.URLEncoder;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPClientConfig;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

public class DownloadAction extends Action{

??? /** *//**?
???? * Method execute
???? * @param mapping
???? * @param form
???? * @param request
???? * @param response
???? * @return ActionForward
???? * @throws IOException?
???? */
??? public ActionForward execute(ActionMapping mapping, ActionForm form,
??????????? HttpServletRequest request, HttpServletResponse response) throws IOException{

????????
??????? OutputStream os=null;
??????????? try {
????????????????
??????????????? os = response.getOutputStream();
????????????????
??????????????? response.reset();???????
????????????????
??????????????? downFile("10.32.166.144", 21, "test", "test", "/flashfxp", "激活码.txt",os,response);
??????????????? //downFile(ip, 21,ftp_user,ftp_pwd,remotePath, filename,os,response);
???????????????
??????????? } catch (IOException e){
??????????????? // TODO Auto-generated catch block
??????????????? e.printStackTrace();
??????????? }finally{
??????????????? try{
??????????????????? os.close();
????????????????????
??????????????? } catch (IOException e){
??????????????????? // TODO Auto-generated catch block
??????????????????? e.printStackTrace();
??????????????? }
????????????????
??????????? }
??????? return null;

??? }

????
/**?
* Description: 从FTP服务器下载文件?
* @param ip FTP服务器ip地址
* @param port FTP服务器端口，默认为21?
* @param username FTP登录账号?
* @param password FTP登录密码?
* @param remotePath 附件在FTP服务器上的绝对路径?
* @param fileName 要下载的文件名?
* @param outputStream 输出流
* @param response?
* @return?
*/?
public static boolean downFile(String ip, int port,String username, String password, String remotePath
??? ,String fileName,OutputStream outputStream,HttpServletResponse response) {???
???? boolean success = false;???
???? FTPClient ftp = new FTPClient();???
???? try {???
???????? int reply;???
?????????ftp.connect(ip, port);
???????? //下面三行代码必须要，而且不能改变编码格式
?????????ftp.setControlEncoding("GBK");
???????? FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_NT);???
???????? conf.setServerLanguageCode("zh");?
????????
???????? //如果采用默认端口，可以使用ftp.connect(url)的方式直接连接FTP服务器???
?????????ftp.login(username, password);//登录???
???????? reply =?ftp.getReplyCode();???
???????? if (!FTPReply.isPositiveCompletion(reply)) {???
?????????????ftp.disconnect();???
???????????? return success;???
???????? }???
?????????
?????????
?????????ftp.changeWorkingDirectory(remotePath);//转移到FTP服务器目录???
???????? FTPFile[] fs =?ftp.listFiles();???
?????????
???????? for(int i = 0; i < fs.length; i++){?
???????? FTPFile ff = fs[i];
???????????? if(ff.getName().equals(fileName)){
?????????????
???????????? String filename = fileName;
???????????????? //这个就就是弹出下载对话框的关键代码
???????????????? response.setHeader("Content-disposition",
??????????????????????????????????? "attachment;filename=" +
??????????????????????????????????? URLEncoder.encode(filename, "utf-8"));
???????????????? //将文件保存到输出流outputStream中
?????????????????ftp.retrieveFile(new?String(ff.getName().getBytes("GBK"),"ISO-8859-1"), outputStream);
???????????????? outputStream.flush();
???????????????? outputStream.close();
???????????? }???
???????? }???
????????????
?????????ftp.logout();???
???????? success = true;???
???? } catch (IOException e) {???
???????? e.printStackTrace();???
???? } finally {???
???????? if (ftp.isConnected()) {???
???????????? try {???
?????????????????ftp.disconnect();???
???????????? } catch (IOException ioe) {???
???????????? }???
???????? }???
???? }???
???? return success;???
}
}

差点忘了利用ftpclient要用到的jar包了，呵呵,就这两个了：commons-net-1.4.1.jar、jakarta-oro-2.0.8.jar

对了我用的jdk是1.4的。所以commons-net-1.4.1.jar用了这个版本比较老的。