FTP 连接报错 java.net.ConnectException: Connection refused: connect

public static boolean downFile(String url, int port,String username, String password, String remotePath,String fileName,String localPath) {
boolean success = false;
FTPClient ftp = new FTPClient();
try {
int reply;
ftp.connect(url, port);

ftp.connect(url);
reply = ftp.getReplyCode();
if (!FTPReply.isPositiveCompletion(reply)) {
ftp.disconnect();
return success;
}
ftp.changeWorkingDirectory(remotePath);
FTPFile[] fs = ftp.listFiles();
for(FTPFile ff:fs){
if(ff.getName().equals(fileName)){
File localFile = new File(localPath+"/"+ff.getName());

OutputStream is = new FileOutputStream(localFile);
ftp.retrieveFile(ff.getName(), is);
is.close();
}
}

ftp.logout();
success = true;
} catch (IOException e) {
e.printStackTrace();
} finally {
if (ftp.isConnected()) {
try {
ftp.disconnect();
} catch (IOException ioe) {
}
}
}
return success;
}
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java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:519)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:176)
at jn.web.yqdz.FtpDown.downFile(FtpDown.java:31)
at jn.web.yqdz.BugXmlTimerTask.run(BugXmlTimerTask.java:15)
at java.util.TimerThread.mainLoop(Timer.java:512)
at java.util.TimerThread.run(Timer.java:462)

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ftp.connect(url, port) url：IP地址 port：FTP端口21

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