plugins/org.eclipse.epp.wizard.installerbuilder/src/org/eclipse/epp/wizard/jnlpbuilder/CustomJnlp.java

/*******************************************************************************
 * Copyright (c) 2008 Innoopract Informationssysteme GmbH.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Innoopract Informationssysteme GmbH - initial API and implementation
 ******************************************************************************/
package org.eclipse.epp.wizard.jnlpbuilder;

import java.io.ByteArrayOutputStream;
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.net.URL;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.epp.wizard.installerbuilder.Activator;
import org.eclipse.epp.wizard.installerbuilder.BuildInstaller;
import org.eclipse.epp.wizard.util.StringUtil;

/**
 * @author Jordi Boehme Lopez <jboehme@innoopract.com>
 */
public class CustomJnlp extends HttpServlet {


  // public static final String OUT_PATH = "/opt/epp/htdocs";
  // public static final String OUT_PATH = "C:/opt/epp/htdocs";
  public static final String JNLP_TEMPLATE_PATH = "templates/jnlp/epp.jnlp";
  private static final String ENCODING = "UTF-8";
  private static final int BUFFER = 512;
  private static final long serialVersionUID = 1L;

  @Override
  protected void doPost( final HttpServletRequest req, 
                         final HttpServletResponse resp)
      throws ServletException, IOException {
    doGet(req, resp);
  }
  
  @Override
  protected void doGet( final HttpServletRequest req,
                        final HttpServletResponse resp )
    throws ServletException, IOException
  {
    String codebase = "http://"
                      + req.getServerName()
                      + ":"
                      + req.getServerPort()
                      + "/download";
    String iuParam = req.getParameter( "eclipse.p2.roots" );
    String metadata = req.getParameter( "eclipse.p2.metadata" );
    String artifacts = req.getParameter( "eclipse.p2.artifacts" );

    resp.addHeader( "Content-Type", "application/x-java-jnlp-file" );
    IPath jnlp_file = execute( codebase, iuParam, metadata, artifacts );
    
    resp.flushBuffer();
    ServletOutputStream os = resp.getOutputStream();
    copy( new FileInputStream(jnlp_file.toFile()) , os);
    os.flush();
  }

  public static IPath execute( final String codebase,
                               final String iuParam, 
                               final String metadata, 
                               final String artifacts ) throws IOException
  {
    File downloadDir = Activator.getDefault()
      .getConfiguration()
      .getDownloadsDirectory();
    IPath outDirPath = new Path( new File( downloadDir,
                                           BuildInstaller.OUTPUT_PATH ).getAbsolutePath() );
    String[] ius = getIUs( iuParam );
    String filename = getFileName( ius );
    IPath outFilePath = outDirPath.append( filename );
    File templateFile = new File( downloadDir, JNLP_TEMPLATE_PATH );
    String jnlp = ceateCustomJnlp( templateFile.toURI().toURL(),
                                   ius,
                                   codebase,
                                   filename,
                                   metadata,
                                   artifacts );
    OutputStream os = new FileOutputStream( outFilePath.toFile() );
    os.write( jnlp.getBytes( ENCODING ) );
    tryClose( os );
    
    return outFilePath;
  }

  // ////////////////
  // helping methods
  // ////////////////
  private static String[] getIUs( final String param ) {
    List<String> result = new ArrayList<String>();
    StringTokenizer tknizr = new StringTokenizer( param, ",", false );
    while( tknizr.hasMoreTokens() ) {
      String token = tknizr.nextToken();
      result.add( token );
    }
    return result.toArray( new String[ result.size() ] );
  }

  private static String ceateCustomJnlp( final URL template,
                                         final String ius[],
                                         final String codebase,
                                         final String filename, 
                                         final String metadata, 
                                         final String artifacts )
  {
    String result = "";
    InputStream in = null;
    try {
      in = template.openStream();
      ByteArrayOutputStream bufferStream = new ByteArrayOutputStream();
      copy( in, bufferStream );
      result = customize( bufferStream.toString( ENCODING ),
                          ius,
                          codebase,
                          filename,
                          metadata, 
                          artifacts );
    } catch( IOException ioe ) {
      ioe.printStackTrace();
    } finally {
      tryClose( in );
    }
    return result;
  }

  private static String customize( final String input,
                                   final String[] ius,
                                   final String codebase,
                                   final String href, 
                                   final String metadata, 
                                   final String artifacts )
  {
    String result = input;
    result = result.replaceAll( "\\$\\{codebase\\}", codebase );
    result = result.replaceAll( "\\$\\{href\\}", href );
    result = result.replaceAll( "\\$\\{roots\\}",
                                StringUtil.toCommaList( ius, false ) );
    result = result.replaceAll( "\\$\\{metadata\\}", metadata );
    result = result.replaceAll( "\\$\\{artifacts\\}", artifacts );
    // FIXME : (jb) get this from initial selection on eclispe.org
    result = result.replaceAll( "\\$\\{profileName\\}", "Custom Eclipse" ); 
    return result;
  }

  private static void tryClose( final InputStream stream ) {
    if( stream != null ) {
      try {
        stream.close();
      } catch( IOException e ) {
        e.printStackTrace();
        // TODO Activator.log( e );
      }
    }
  }

  private static void tryClose( final OutputStream stream ) {
    if( stream != null ) {
      try {
        stream.close();
      } catch( IOException e ) {
        e.printStackTrace();
        // TODO Activator.log( e );
      }
    }
  }

  private static void copy( final InputStream in, final OutputStream out )
    throws IOException
  {
    byte[] data = new byte[ BUFFER ];
    int currentByte = in.read( data, 0, BUFFER );
    while( currentByte != -1 ) {
      out.write( data, 0, currentByte );
      currentByte = in.read( data, 0, BUFFER );
    }
  }

  public static String getFileName( final String[] ids ) {
    String hash = ids.toString();
    try {
      hash = StringUtil.getHash( ids );
    } catch( NoSuchAlgorithmException exc ) {
      // should not happen! - but trace anyway
      exc.printStackTrace();
    }
    return "startinstaller-" + hash + ".jnlp";
  }
}