Java implementation of FTP breakpoint upload method _java

This article describes the Java implementation of FTP breakpoint upload method. Share to everyone for your reference. The specific analysis is as follows:

This is mainly implemented using the net package in Apache. URL http://commons.apache.org/net/. Download the specific package and API documentation please reader network. A breakpoint upload sets the starting position of the transmission during the upload process. and set the binary transmission.

Import Java.io.File; 
Import Java.io.FileInputStream; 
Import Java.io.FileOutputStream; 
Import java.io.IOException; 
Import Java.io.InputStream; 
Import Java.io.OutputStream; 
Import Java.io.PrintWriter; 
Import Org.apache.commons.net.PrintCommandListener; 
Import Org.apache.commons.net.ftp.FTP; 
Import org.apache.commons.net.ftp.FTPClient; 
Import Org.apache.commons.net.ftp.FTPFile; 
Import org.apache.commons.net.ftp.FTPReply; 
   public class Continueftp {private FtpClient ftpclient = new FtpClient (); The public continueftp () {//sets the command used in the procedure to output to the console This.ftpClient.addProtocolCommandListener new Printcommandlistener ( 
   New PrintWriter (System.out))); /** * Java Programming for connecting to FTP server * @param hostname host name * @param port * @param username username * @param p Assword Password * @return Whether the connection succeeded * @throws IOException/public boolean connect (String hostname,int Port,strin G username,string password) throws ioexception{Ftpclient.connect (hostname,Port); if (Ftpreply.ispositivecompletion (Ftpclient.getreplycode ())) {if (Ftpclient.login (username, password)) {RE 
       Turn true; 
     } disconnect (); 
   return false; /** * Download files from FTP server * @param remote file path * @param local file path * @return Success * @throws IOEXCEP tion */public boolean download (String remote,string local) throws ioexception{Ftpclient.enterlocalpassivem 
     Ode (); 
     Ftpclient.setfiletype (Ftp.binary_file_type); 
     Boolean result; 
     File F = new file (local); 
     ftpfile[] files = ftpclient.listfiles (remote); 
       if (files.length!= 1) {System.out.println ("Remote file is not unique"); 
     return false; 
     Long lremotesize = Files[0].getsize (); 
       if (f.exists ()) {OutputStream out = new FileOutputStream (f,true); 
       SYSTEM.OUT.PRINTLN ("Local File size is:" +f.length ()); 
         if (F.length () >= lremotesize) {System.out.println ("Local file size is larger than remote file size, download aborted"); Return false; 
       } ftpclient.setrestartoffset (F.length ()); 
       result = Ftpclient.retrievefile (remote, out); 
     Out.close (); 
       }else {OutputStream out = new FileOutputStream (f); 
       result = Ftpclient.retrievefile (remote, out); 
     Out.close (); 
   return result; /** * Upload files to FTP server, support breakpoint continued * @param local file name, absolute path * @param remote file path, using/home/directory1/subdirecto Ry/file.ext in accordance with the path specified on Linux, support multilevel directory nesting, support recursively create nonexistent directory structure * @return upload results * @throws ioexception/public uploads Tatus upload (String local,string remote) throws ioexception{//set Passivemode transmission Ftpclient.enterlocalpassivemode 
     (); 
     A binary stream is set to transmit Ftpclient.setfiletype (ftp.binary_file_type); 
     Uploadstatus result; 
     Processing of remote directories String remotefilename = remote; 
       if (Remote.contains ("/")) {remotefilename = remote.substring (Remote.lastindexof ("/") +1); String directory = remote.substring (0,remote.lastiNdexof ("/") +1); if (!directory.equalsignorecase ("/") &&!ftpclient.changeworkingdirectory (directory) {//If the remote directory does not exist, recursively creates a remote 
         Server directory int start=0; 
         int end = 0; 
         if (Directory.startswith ("/")) {start = 1; 
         }else{start = 0; 
         End = Directory.indexof ("/", start);
           while (true) {String subdirectory = remote.substring (start,end); 
               if (!ftpclient.changeworkingdirectory (subdirectory)) {if (Ftpclient.makedirectory (subdirectory)) { 
             Ftpclient.changeworkingdirectory (subdirectory); 
               }else {System.out.println ("Create directory Failed");
             return uploadstatus.create_directory_fail; 
           } start = end + 1; 
           End = Directory.indexof ("/", start); 
           Check that all directories are created if (end <= start) {break; Check the remote,}}}//Whether there is a file ftpfile[] files = ftpclient.listfiles (remotefilename); 
       if (files.length = = 1) {Long remotesize = Files[0].getsize (); 
       File F = new file (local); 
       Long localsize = F.length (); 
       if (remotesize==localsize) {return uploadstatus.file_exits; 
       }else if (Remotesize > Localsize) {return uploadstatus.remote_bigger_local; 
       //Attempt to move the read pointer within the file to implement the breakpoint InputStream is = new FileInputStream (f); 
         if (Is.skip (remotesize) ==remotesize) {ftpclient.setrestartoffset (remotesize); 
         if (Ftpclient.storefile (remote, is)) {return uploadstatus.upload_from_break_success; }//If the breakpoint is not successful, delete the file on the server and upload if (!ftpclient.deletefile (Remotefilename)) {return Upload 
       Status.delete_remote_faild; 
       is = new FileInputStream (f); 
       if (Ftpclient.storefile (remote, is)} {result = Uploadstatus.upload_new_file_success; }else{result = uploadstatus.upload_new_file_failed; 
     } is.close (); 
       }else {InputStream is = new FileInputStream (local); 
       if (Ftpclient.storefile (Remotefilename, is)} {result = Uploadstatus.upload_new_file_success; 
       }else{result = uploadstatus.upload_new_file_failed; 
     } is.close (); 
   return result; /** * Disconnect from remote server * @throws IOException */public void disconnect () throws ioexception{if (FTP 
     Client.isconnected ()) {ftpclient.disconnect (); 
     } public static void Main (string[] args) {continueftp myftp = new Continueftp (); 
       try {myftp.connect ("192.168.21.171," "Test", "test"); 
       System.out.println (Myftp.upload ("e:\\vp6.flv", "/mis/video/vp6.flv")); 
     Myftp.disconnect (); 
     catch (IOException e) {System.out.println ("Connection FTP error:" +e.getmessage ());

 } 
   } 
}

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