JarUtilities.java

/*
 * GovWay - A customizable API Gateway 
 * https://govway.org
 * 
 * Copyright (c) 2005-2025 Link.it srl (https://link.it). 
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3, as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */


package org.openspcoop2.utils.io;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.JarURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.Manifest;

import org.openspcoop2.utils.Utilities;
import org.openspcoop2.utils.UtilsException;


/**
 * JarUtilities
 *
 *
 * @author Poli Andrea (apoli@link.it)
 * @author $Author$
 * @version $Rev$, $Date$
 */
public class JarUtilities {

    public static boolean isJar(File file,boolean checkExtension){
        try{    
            JarFile jar = JarUtilities.getJar(file, checkExtension);
            return jar!=null;           
        }catch (Exception e){
            return false;
        }
    }
    
    public static JarFile getJar(File file,boolean checkExtension) throws UtilsException{
        try{
            
            if(checkExtension){
                if(file.getName().endsWith(".jar")==false){
                    throw new Exception("Estensione del file diversa da quella attesa");
                }
            }
            JarURLConnection conn = JarUtilities.getConnection(file, null);
            return conn.getJarFile();
                        
        }catch (Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    
    public static Manifest getManifest(File file) throws UtilsException{
        try{
            JarURLConnection conn = JarUtilities.getConnection(file, null);
            return conn.getManifest();
        }catch (Exception e){
            throw new UtilsException(e.getMessage(),e);
        }
    }
    
    public static byte[] getEntry(File jarFile,String jarEntry) throws UtilsException{
        
        InputStream is = null;
        try{
            
            JarURLConnection conn = JarUtilities.getConnection(jarFile, jarEntry);
            JarFile jar = conn.getJarFile();
            JarEntry entry = conn.getJarEntry();
            if(entry==null){
                return null;
            }
            
            is = jar.getInputStream(entry);
            byte [] buffer = Utilities.getAsByteArray(is);
            return buffer;
            
        }catch (Exception e){
            throw new UtilsException(e.getMessage(),e);
        }finally{
            try{
                if(is!=null) {
                    is.close();
                }
            }catch(Exception eclose){
                // close
            }
        }
    }
    
    private static JarURLConnection getConnection(File jarFile,String jarEntry) throws MalformedURLException, IOException{
        URL archivio = new URL ("file://" + jarFile.getCanonicalPath ());
        String url = "jar:" + archivio.toExternalForm () + "!/";
        if(jarEntry!=null){
            url = url + jarEntry;
        }
        archivio = new URL (url);
        return (JarURLConnection) archivio.openConnection ();
    }
    
}