java ftp下载文件问题，用的包是commons-net-1.4.1,jar
文件下载一直失败，那个文件我能通过retrieveFileStream读取到客户端。只能求高手指点了……public void loadFile(String remoteFileName,String localFileName){
//下载文件
OutputStream osOutputStream = null;
try{
File localFile = new File(localFileName);
osOutputStream = new FileOutputStream(localFile);
boolean suc = ftpClient.retrieveFile(new String(remoteFileName.getBytes("GBK"),"ISO-8859-1"),osOutputStream );
if (suc) {
System.out.println("下载文件成功");
}
else {
System.out.println("文件下载失败");
}
osOutputStream.close();
}catch(Exception e){
e.printStackTrace();
}finally{
try{
if (osOutputStream != null) {
osOutputStream.close();
}
}catch(Exception e){
e.printStackTrace();
}
}
}
--------------------编程问答-------------------- 额……解决不了啊，网上全是这个方法，为什么我的就不行
--------------------编程问答-------------------- FTP编程，一般就三大问题，楼主看看是哪一个 ？
1.主动模式 和 被动模式 问题；
2.命令连接 和 数据连接 问题；
3.文件数据的编码传输问题。
1.客户端这边存在NAT或者PAT的时候（或者路由器，防火墙的时候），采用被动模式进行下载即可。
2.网络较慢或者文件数据较大使得数据传输时间超长，造成控制连接被中间节点（防火墙或路由器）强行断开。当然，有的服务器也会自行断开超时的控制连接。
3.传输文件可以选用ACSII码和Binary进行传输，在选用ACSII码时由于操作系统不同，回车换行符的内容有可能会被更改。
--------------------编程问答--------------------
--------------------编程问答--------------------
// 设置以二进制形式传输
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
ftpClient.enterLocalPassiveMode();--------------------编程问答--------------------
都加了还是不行……再用sun的试试了只能。 --------------------编程问答-------------------- import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import nc.itf.doc.DocDelegator;
import nc.vo.doc.doc_007.DirVO;
import nc.vo.pub.BusinessException;
import nc.vo.pub.SuperVO;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;
import org.apache.commons.net.ftp.FTP;
public class FtpTool {
private FTPClient ftp;
private String romateDir = "";
private String userName = "";
private String password = "";
private String host = "";
private String port = "21";
public FtpTool(String url) throws IOException {
//String url="ftp://user:password@ip:port/ftptest/psd";
int len = url.indexOf("//");
String strTemp = url.substring(len + 2);
len = strTemp.indexOf(":");
userName = strTemp.substring(0, len);
strTemp = strTemp.substring(len + 1);
len = strTemp.indexOf("@");
password = strTemp.substring(0, len);
strTemp = strTemp.substring(len + 1);
host = "";
len = strTemp.indexOf(":");
if (len < 0)//没有设置端口
{
port = "21";
len = strTemp.indexOf("/");
if (len > -1) {
host = strTemp.substring(0, len);
strTemp = strTemp.substring(len + 1);
} else {
strTemp = "";
}
} else {
host = strTemp.substring(0, len);
strTemp = strTemp.substring(len + 1);
len = strTemp.indexOf("/");
if (len > -1) {
port = strTemp.substring(0, len);
strTemp = strTemp.substring(len + 1);
} else {
port = "21";
strTemp = "";
}
}
romateDir = strTemp;
ftp = new FTPClient();
ftp.connect(host, FormatStringToInt(port));
}
public FtpTool(String host, int port) throws IOException {
ftp = new FTPClient();
ftp.connect(host, port);
}
public String login(String username, String password) throws IOException {
this.ftp.login(username, password);
return this.ftp.getReplyString();
}
public String login() throws IOException {
this.ftp.login(userName, password);
System.out.println("ftp用户: " + userName);
System.out.println("ftp密码: " + password);
if (!romateDir.equals(""))
System.out.println("cd " + romateDir);
ftp.changeWorkingDirectory(romateDir);
return this.ftp.getReplyString();
}
public boolean upload(String pathname, String filename) throws IOException, BusinessException {
int reply;
int j;
String m_sfilename = null;
filename = CheckNullString(filename);
if (filename.equals(""))
return false;
reply = ftp.getReplyCode();
if (!FTPReply.isPositiveCompletion(reply)) {
ftp.disconnect();
System.out.println("FTP server refused connection.");
System.exit(1);
}
FileInputStream is = null;
try {
File file_in;
if (pathname.endsWith(File.separator)) {
file_in = new File(pathname + filename);
} else {
file_in = new File(pathname + File.separator + filename);
}
if (file_in.length() == 0) {
System.out.println("上传文件为空!");
return false;
}
//产生随机数最大到99
j = (int)(Math.random()*100);
m_sfilename = String.valueOf(j) + ".pdf"; // 生成的文件名
is = new FileInputStream(file_in);
ftp.setFileType(FTP.BINARY_FILE_TYPE);
ftp.storeFile(m_sfilename, is);
ftp.logout();
} finally {
if (is != null) {
is.close();
}
}
System.out.println("上传文件成功!");
return true;
}
public boolean delete(String filename) throws IOException {
FileInputStream is = null;
boolean retValue = false;
try {
retValue = ftp.deleteFile(filename);
ftp.logout();
} finally {
if (is != null) {
is.close();
}
}
return retValue;
}
public void close() {
if (ftp.isConnected()) {
try {
ftp.disconnect();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public static int FormatStringToInt(String p_String) {
int intRe = 0;
if (p_String != null) {
if (!p_String.trim().equals("")) {
try {
intRe = Integer.parseInt(p_String);
} catch (Exception ex) {
}
}
}
return intRe;
}
public static String CheckNullString(String p_String) {
if (p_String == null)
return "";
else
return p_String;
}
public boolean downfile(String pathname, String filename) {
String outputFileName = null;
boolean retValue = false;
try {
FTPFile files[] = ftp.listFiles();
int reply = ftp.getReplyCode();
////////////////////////////////////////////////
if (!FTPReply.isPositiveCompletion(reply)) {
try {
throw new Exception("Unable to get list of files to dowload.");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/////////////////////////////////////////////////////
if (files.length == 0) {
System.out.println("No files are available for download.");
}else {
for (int i=0; i <files.length; i++) {
System.out.println("Downloading file "+files[i].getName()+"Size:"+files[i].getSize());
outputFileName = pathname + filename + ".pdf";
//return outputFileName;
File f = new File(outputFileName);
//////////////////////////////////////////////////////
retValue = ftp.retrieveFile(outputFileName, new FileOutputStream(f));
if (!retValue) {
try {
throw new Exception ("Downloading of remote file"+files[i].getName()+" failed. ftp.retrieveFile() returned false.");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
/////////////////////////////////////////////////////////////
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return retValue;
}
} --------------------编程问答-------------------- c
补充：Java , Java SE
