EnvironmentHelper.java :  » ERP-CRM-Financial » JFire-1.0.1 » org » nightlabs » installer » Java Open Source

package org.nightlabs.installer;

import java.io.File;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;

/**
 * @author Marc Klinger - marc[at]nightlabs[dot]de
 */
public class EnvironmentHelper
{
  private static final String JAR_PREFIX = "jar:"; //$NON-NLS-1$

  public static boolean isWindows()
  {
    String osName = System.getProperty("os.name"); //$NON-NLS-1$
    return osName != null && osName.startsWith("Windows"); //$NON-NLS-1$
  }

  /**
   * @param classInTopLevel This is a class in the top-level of the jar (i.e. not in a nested jar).
   */
  public static File getEnclosingJar(Class<?> classInTopLevel)
  {
    URL classURL = classInTopLevel.getResource(classInTopLevel.getSimpleName()+".class"); //$NON-NLS-1$
    //Logger.out.println("class url: "+classURL);
    String fileInJar = classURL.toString();

    if(fileInJar.startsWith(JAR_PREFIX)) {
      int end = fileInJar.indexOf('!', JAR_PREFIX.length());
      if(end != -1) {
        String jarURL = fileInJar.substring(JAR_PREFIX.length(), end);
        //Logger.out.println("class url: "+jarURL);
        File f;
        try {
          URI uri = new URI(jarURL);
          //Logger.out.println("class uri: "+uri.toString());
          try {
            f = new File(uri);
          } catch(IllegalArgumentException e) {
            // this is a windows share file path if: 
            // authority is not null 
            // and we are under windows 
            // and the url starts with "file://" instead of "file:/"
            if(uri.getAuthority() != null && isWindows() && jarURL.startsWith("file://")) { //$NON-NLS-1$
              f = new File("\\\\"+jarURL.substring("file://".length()).replace("/", "\\")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
            } else {
              throw e;
            }
          }
          //Logger.out.println("class file: "+f.getAbsolutePath());
        } catch (URISyntaxException e) {
          return null;
        }
        if(f.exists())
          return f;
      }
    }
    return null;
  }


//  /**
//   * This method reads the jar within we're running from the system properties, key "java.class.path".
//   */ 
//  public static File getEnclosingJar()
//  {
//    for (Map.Entry<Object, Object> me : System.getProperties().entrySet()) {
//      Logger.out.println(String.valueOf(me.getKey()) + " => " + me.getValue());
//      Logger.out.println("");
//    }
//    return null;
//  }
}