f@0: /*  
f@0:  CCmI Editor - A Collaborative Cross-Modal Diagram Editing Tool
f@0:   
f@0:  Copyright (C) 2011  Queen Mary University of London (http://ccmi.eecs.qmul.ac.uk/)
f@0: 
f@0:  This program is free software: you can redistribute it and/or modify
f@0:  it under the terms of the GNU General Public License as published by
f@0:  the Free Software Foundation, either version 3 of the License, or
f@0:  (at your option) any later version.
f@0: 
f@0:  This program is distributed in the hope that it will be useful,
f@0:  but WITHOUT ANY WARRANTY; without even the implied warranty of
f@0:  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
f@0:  GNU General Public License for more details.
f@0: 
f@0:  You should have received a copy of the GNU General Public License
f@0:  along with this program.  If not, see <http://www.gnu.org/licenses/>.
f@0: */  
f@0: 
f@0: package uk.ac.qmul.eecs.ccmi.utils;
f@0: 
f@0: import java.io.File;
f@0: import java.io.FileOutputStream;
f@0: import java.io.IOException;
f@0: import java.io.InputStream;
f@0: import java.net.URL;
f@0: 
f@0: /**
f@0:  * This class is used to store a resource (e.g. .dll file in windows)to the local file system.
f@0:  * 
f@0:  * This class can be used to allow the virtual machine to load resources which come embedded  
f@0:  * into a jar file.
f@0:  */
f@0: public class ResourceFileWriter {
f@0: 	
f@0: 	/**
f@0: 	 * Creates an instance of the the class linked to no resource. an resource file writer 
f@0: 	 * created with this constructor is useless, unless {@code setResource} is called before
f@0: 	 * writing the resource on the disk.
f@0: 	 * 
f@0: 	 * @see Class#getResource(String)  
f@0: 	 */
f@0: 	public ResourceFileWriter(){
f@0: 	}
f@0: 	
f@0: 	/**
f@0: 	 * Creates an instance of the the class linked to a specific resource 
f@0: 	 * 
f@0: 	 * @param resource the resource URL. The URL can be obtained by  
f@0: 	 * {@code getResource}, therefore can be called from a class within a jar file
f@0: 	 * which needs to access embedded resources.  
f@0: 	 */
f@0: 	public ResourceFileWriter(URL resource){
f@0: 		this.resource = resource;
f@0: 	}
f@0: 	
f@0: 	/**
f@0: 	 * Sets a new resource for this resource file writer. Successive calls to {@code writeToDisk} 
f@0: 	 * will store the resouce passed as argument in the file system. 
f@0: 	 * 
f@0: 	 * @param resource the URL of the new resource this resource file writer is linked to 
f@0: 	 */
f@0: 	public void setResource(URL resource){
f@0: 		this.resource = resource;;
f@0: 		path = null;
f@0: 	}
f@0: 
f@0: 	/**
f@0: 	 * Writes the resource in the file passed as argument.
f@0: 	 * 
f@0: 	 * The path to the file can be retrieved afterwards through @see {@link #getFilePath()} 
f@0: 	 * 
f@0: 	 * @param dir the directory where the resource will be saved
f@0: 	 * @param fileName the name of the file the resoruce will be saved in 
f@0: 	 */
f@0: 	public void writeOnDisk(String dir,String fileName){
f@0: 		if (resource == null) 
f@0: 			return;
f@0: 		InputStream in = null;
f@0: 		FileOutputStream out = null;
f@0: 		File file = new File(dir,fileName);
f@0: 		if(file.exists()){ //if file already exists. no job needs to be done.
f@0: 			path = file.getAbsolutePath();
f@0: 			return;
f@0: 		}
f@0: 		try{
f@0: 			in = resource.openStream();
f@0: 			out = new FileOutputStream(file);
f@0: 			int byteRead;
f@0: 			byte[] b = new byte[1024];
f@0: 			while((byteRead = in.read(b)) > 0){
f@0: 				out.write(b, 0, byteRead);
f@0: 			}
f@0: 			path = file.getAbsolutePath();
f@0: 		}catch(IOException ioe){
f@0: 			path = null;
f@0: 		}finally{
f@0: 			if(in != null) 
f@0: 				try{in.close();}catch(IOException ioe){ioe.printStackTrace();}
f@0: 			if(out != null) 
f@0: 				try{out.close();}catch(IOException ioe){ioe.printStackTrace();}	
f@0: 		}
f@0: 		
f@0: 	}
f@0: 	
f@0: 	/**
f@0: 	 * Returns the absolute path of the last written file. If the writing wasn't successfully 
f@0: 	 * or no writing took place yet, then {@code null} is returned. 
f@0: 	 * 
f@0: 	 * @return the path of the last written file or {@code null} if no resource was set for this 
f@0: 	 * resource file writer or {@code writeToDisk}  was unsuccessful
f@0: 	 */
f@0: 	public String getFilePath(){
f@0: 		return path;
f@0: 	}
f@0: 	
f@0: 	private URL resource;
f@0: 	private String path;
f@0: }