fileuploadthread.java

groupoffice

package jupload;

import java.io.*;
import java.net.*;
import java.util.*;
import javax.swing.*;

  /*
   * Known Bugs: System out of memory Exception.
   * Solution  : Nothing!
   * Tryed but didn't work:
   *             - Flush the OutputStream once it has outputed 1MB.
   *             - Call System.gc() once it has outputed 1MB.
   *             - Sleep for 1 Second so that System GC gets a chance to run.
   * Work Around: Breakup the file into smaller ones then upload =)
   */
public class FileUploadThread extends Thread {
    
    //------------- INFORMATION --------------------------------------------
    public static final double VERSION = 1.0;
    public static final String AUTHOR = "William Kwong Jinhua";
    public static final String AUTHOR_EMAIL = "[e-mail]";
    public static final String DESCRIPTION = "Java Thread to upload files into a web server.";
    public static final String LAST_MODIFIED = "01 July 2002";
    
    //------------- STATUS OF THREAD ---------------------------------------
    // Files asked to be uploaded into the server.
    private File[] aTotalFiles;
    private String uploadURL;
    
    // Progress Bar.
    private JProgressBar progress;
    private long totalFilesLength;
    private long uploadedLength;
    
    // Server Output.
    private StringBuffer sb = new StringBuffer();
    private void addServerOutPut(String s){
        if(0 < sb.length() || !s.equals("")){
            sb.append(s);
        }
    }
    public StringBuffer getServerOutput(){
        return sb;
    }
    
    private Exception e = null;
    public Exception getException(){
        return e;
    }
    
    public void setProgressPanel(JProgressBar pgrBar){
        progress = pgrBar;
    }
    
    private boolean stop = false;
    public void stopUpload(){
        this.stop = true;
    }
    
    //------------- CONSTRUCTOR --------------------------------------------
    
    public FileUploadThread(File[] files, String uploadURL){
        aTotalFiles = files;
        this.uploadURL = uploadURL;
        totalFilesLength = 0;
        for(int i=0; i < aTotalFiles.length; i++){
            totalFilesLength += aTotalFiles[i].length();
        }
    }
    
    //------------- CLEAN UP -----------------------------------------------
    public void close(){
        aTotalFiles = null;
        
        e = null;
        
        sb = null;
        
    }
    
    //------------- THE HEART OF THE PROGRAME ------------------------------
    
    public void run() {
        URL url = null;
        URLConnection urlConn = null;
        DataOutputStream dOut = null;
        BufferedReader bInp = null;
        try{
            url = new URL(uploadURL);
            // Setting up the connection for upload.
            urlConn = url.openConnection();
            urlConn.setDoInput(true);
            urlConn.setDoOutput(true);
            urlConn.setUseCaches(false);
            String boundary = "-----------------------------" + getRandomString();
            urlConn.setRequestProperty("Content-Type",
                    "multipart/form-data; boundary=" +
                    boundary.substring(2, boundary.length()));
            String CRLF = "\r\n";
            
            // Retrieve OutputStream For upload (Post).
            dOut = new DataOutputStream(urlConn.getOutputStream());
            
            // Actual Uploading part.
            StringBuffer sb;
            File f;
            uploadedLength = 0;
            progress.setMaximum((int)totalFilesLength);
            for(int i=0; i < aTotalFiles.length && !stop; i++){
                f = aTotalFiles[i];
                sb = new StringBuffer();
                // Line 1.
                sb.append(boundary);sb.append(CRLF);
                // Line 2.
                sb.append("Content-Disposition: form-data; name=\"File");sb.append(i);
                sb.append("\"; filename=\"");sb.append(f.toString());
                sb.append("\"");sb.append(CRLF);
                // Line 3 & Empty Line 4.
                sb.append("Content-Type: application/octet-stream");
                sb.append(CRLF);sb.append(CRLF);
                // Write to Server the 4 Lines, a File and the CRLF.
                dOut.writeBytes(sb.toString());
                uploadFileStream(f,dOut);
                dOut.writeBytes(CRLF);
            }
            // Telling the Server we have Finished.
            dOut.writeBytes(boundary);dOut.writeBytes("--");dOut.writeBytes(CRLF);
            dOut.flush();
            if(!stop) progress.setString("File(s) uploaded. Wait for server response!");
            
            // Reading input from Server.
            // NOTE: You have to call getInputStream AFTER you have posted all
            // your files. Anything you try to write to the server after calling the
            // getInputStream will be lost.
            // PROBLEM: You will only find out the status of the server (server/page
            // is reachable/exists) after getInputStream. It would be very bad if
            // we spend all our time writing to it then find out it was down or
            // page doesn't exist!
            // -- Server Down --
            // java.net.SocketException: Connection reset by peer: JVM_recv in socket input stream read
            // java.net.SocketException: Unexpected end of file from server.
            // -- Post page not found --
            // java.io.FileNotFoundException: <<URL>>
            bInp = new BufferedReader(new InputStreamReader(urlConn.getInputStream()));
            
            String str;
            while (null != ((str = bInp.readLine()))){
                this.addServerOutPut(str);
            }
        }catch(Exception e){
            this.e = e;
        }finally{
            try{
                bInp.close();
            }catch(Exception e){}
            bInp = null;
            try{
                dOut.close();
            }catch(Exception e){}
            dOut = null;
            urlConn = null;
            url = null;
        }
    }
    
    private String getRandomString(){
        String alphaNum="1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
        StringBuffer sbRan = new StringBuffer(11);
        int num;
        for(int i = 0; i < 11; i++){
            num = (int)(Math.random()* (alphaNum.length() - 1));
            sbRan.append(alphaNum.substring(num, num+1));
        }
        return sbRan.toString();
    }
    
    private void uploadFileStream(File f, DataOutputStream dOut)
    throws FileNotFoundException,
            IOException{
        byte[] byteBuff = null;
        FileInputStream fis = null;
        try{
            int numBytes = 0;
            byteBuff = new byte[1024];
            fis = new FileInputStream(f);
            while(-1 != (numBytes = fis.read(byteBuff)) && !stop){
                dOut.write(byteBuff, 0, numBytes);
                uploadedLength += numBytes;
                if(null != progress) progress.setValue((int)uploadedLength);
            }
        }finally{
            try{
                fis.close();
            }catch(Exception e){}
            byteBuff = null;
        }
    }
}