org.eclipse.sisu.inject/src/org/eclipse/sisu/space/URLClassSpace.java - sisu/org.eclipse.sisu.inject - Git at Google

 /*******************************************************************************
  * Copyright (c) 2010, 2015 Sonatype, Inc.
  * 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:
  *    Stuart McCulloch (Sonatype, Inc.) - initial API and implementation
  *******************************************************************************/
 package org.eclipse.sisu.space;

 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.jar.JarFile;
 import java.util.jar.JarInputStream;
 import java.util.jar.Manifest;

 import org.eclipse.sisu.inject.DeferredClass;

 /**
  * {@link ClassSpace} backed by a strongly-referenced {@link ClassLoader} and a {@link URL} class path.
  */
 public class URLClassSpace
     implements ClassSpace
 {
     // ----------------------------------------------------------------------
     // Static initialization
     // ----------------------------------------------------------------------

     static
     {
         ClassLoader systemLoader;
         String classPath;
         try
         {
             systemLoader = ClassLoader.getSystemClassLoader();
             classPath = System.getProperty( "java.class.path", "." );
         }
         catch ( final RuntimeException e )
         {
             systemLoader = null;
             classPath = null;
         }
         catch ( final LinkageError e )
         {
             systemLoader = null;
             classPath = null;
         }
         SYSTEM_LOADER = systemLoader;
         SYSTEM_CLASSPATH = classPath;
     }

     // ----------------------------------------------------------------------
     // Constants
     // ----------------------------------------------------------------------

     private static final String MANIFEST_ENTRY = "META-INF/MANIFEST.MF";

     private static final URL[] NO_URLS = {};

     private static final Enumeration<URL> NO_ENTRIES = Collections.enumeration( Collections.<URL> emptySet() );

     private static final String[] EMPTY_CLASSPATH = {};

     private static final ClassLoader SYSTEM_LOADER;

     private static final String SYSTEM_CLASSPATH;

     // ----------------------------------------------------------------------
     // Implementation fields
     // ----------------------------------------------------------------------

     private final ClassLoader loader;

     private final String pathDetails;

     private URL[] classPath;

     // ----------------------------------------------------------------------
     // Constructors
     // ----------------------------------------------------------------------

     /**
      * Creates a {@link ClassSpace} backed by a {@link ClassLoader} and its default class path.
      * <p>
      * For {@link URLClassLoader}s this is their expanded Class-Path; otherwise it is empty.
      *
      * @param loader The class loader to use when getting/finding resources
      */
     public URLClassSpace( final ClassLoader loader )
     {
         this.loader = loader;
         pathDetails = null;
         // compute class path on demand
     }

     /**
      * Creates a {@link ClassSpace} backed by a {@link ClassLoader} with a restricted class path.
      *
      * @param loader The class loader to use when getting resources
      * @param path The class path to use when finding resources
      * @see #getResources(String)
      * @see #findEntries(String, String, boolean)
      */
     public URLClassSpace( final ClassLoader loader, final URL[] path )
     {
         this.loader = loader;
         pathDetails = Arrays.toString( path );
         if ( null != path && path.length > 0 )
         {
             classPath = expandClassPath( path );
         }
         else
         {
             classPath = NO_URLS;
         }
     }

     // ----------------------------------------------------------------------
     // Public methods
     // ----------------------------------------------------------------------

     public final Class<?> loadClass( final String name )
     {
         try
         {
             return loader.loadClass( name );
         }
         catch ( final Exception e )
         {
             throw new TypeNotPresentException( name, e );
         }
         catch ( final LinkageError e )
         {
             throw new TypeNotPresentException( name, e );
         }
     }

     public final DeferredClass<?> deferLoadClass( final String name )
     {
         return new NamedClass<Object>( this, name );
     }

     public final URL getResource( final String name )
     {
         return loader.getResource( name );
     }

     public final Enumeration<URL> getResources( final String name )
     {
         try
         {
             final Enumeration<URL> resources = loader.getResources( name );
             return null != resources ? resources : NO_ENTRIES; // NOSONAR
         }
         catch ( final IOException e )
         {
             return NO_ENTRIES;
         }
     }

     public final Enumeration<URL> findEntries( final String path, final String glob, final boolean recurse )
     {
         return new ResourceEnumeration( path, glob, recurse, getClassPath() );
     }

     public final URL[] getURLs()
     {
         return getClassPath().clone();
     }

     @Override
     public final int hashCode()
     {
         return loader.hashCode(); // the loader is the primary key
     }

     @Override
     public final boolean equals( final Object rhs )
     {
         if ( this == rhs )
         {
             return true;
         }
         if ( rhs instanceof URLClassSpace )
         {
             return loader.equals( ( (URLClassSpace) rhs ).loader );
         }
         return false;
     }

     @Override
     public final String toString()
     {
         return null == pathDetails ? loader.toString() : loader + "(" + pathDetails + ")";
     }

     // ----------------------------------------------------------------------
     // Implementation methods
     // ----------------------------------------------------------------------

     /**
      * Returns the associated {@link URL} class path; this can either be explicit or implicit.
      */
     private synchronized URL[] getClassPath()
     {
         if ( null == classPath )
         {
             for ( ClassLoader l = loader; l != null; l = l.getParent() )
             {
                 if ( l instanceof URLClassLoader )
                 {
                     // pick first class loader with non-empty class path
                     final URL[] path = ( (URLClassLoader) l ).getURLs();
                     if ( null != path && path.length > 0 )
                     {
                         classPath = expandClassPath( path );
                         break;
                     }
                 }
                 else if ( null != SYSTEM_LOADER && l == SYSTEM_LOADER )
                 {
                     classPath = expandClassPath( getSystemClassPath() );
                     break;
                 }
             }
             if ( null == classPath )
             {
                 classPath = NO_URLS; // no detectable Class-Path
             }
         }
         return classPath;
     }

     /**
      * Returns the system {@link URL} class path.
      */
     private static URL[] getSystemClassPath()
     {
         final String[] paths = SYSTEM_CLASSPATH.split( File.pathSeparator );

         final URL[] urls = new URL[paths.length];
         for ( int i = 0; i < paths.length; i++ )
         {
             try
             {
                 urls[i] = ( new File( paths[i] ).toURI().toURL() );
             }
             catch ( final MalformedURLException e )
             {
                 urls[i] = null; // ignore malformed class-path entry
             }
         }
         return urls;
     }

     /**
      * Expands the given {@link URL} class path to include Class-Path entries from local manifests.
      *
      * @param classPath The URL class path
      * @return Expanded URL class path
      */
     private static URL[] expandClassPath( final URL[] classPath )
     {
         final List<URL> searchPath = new ArrayList<URL>();
         Collections.addAll( searchPath, classPath );

         final List<URL> expandedPath = new ArrayList<URL>();
         final Set<String> visited = new HashSet<String>();

         // search path may grow, so use index not iterator
         for ( int i = 0; i < searchPath.size(); i++ )
         {
             final URL url = normalizeEntry( searchPath.get( i ) );
             if ( null == url || !visited.add( url.toString() ) )
             {
                 continue; // already processed
             }
             expandedPath.add( url );
             final String[] classPathEntries;
             try
             {
                 classPathEntries = getClassPathEntries( url );
             }
             catch ( final IOException e )
             {
                 continue; // missing manifest
             }
             for ( final String entry : classPathEntries )
             {
                 try
                 {
                     searchPath.add( new URL( url, entry ) );
                 }
                 catch ( final MalformedURLException e ) // NOPMD
                 {
                     // invalid Class-Path entry
                 }
             }
         }

         return expandedPath.toArray( new URL[expandedPath.size()] );
     }

     /**
      * Normalizes the given class path entry by removing any extraneous "jar:"..."!/" padding.
      *
      * @param path The URL to normalize
      * @return Normalized class path entry
      */
     private static URL normalizeEntry( final URL url )
     {
         if ( null != url && "jar".equals( url.getProtocol() ) )
         {
             final String path = url.getPath();
             if ( path.endsWith( "!/" ) )
             {
                 try
                 {
                     return new URL( path.substring( 0, path.length() - 2 ) );
                 }
                 catch ( final MalformedURLException e )
                 {
                     // this shouldn't happen, hence illegal state
                     throw new IllegalStateException( e.toString() );
                 }
             }
         }
         return url;
     }

     /**
      * Looks for Class-Path entries in the given jar or directory; returns empty array if none are found.
      *
      * @param url The jar or directory to inspect
      * @return Array of Class-Path entries
      */
     private static String[] getClassPathEntries( final URL url )
         throws IOException
     {
         final Manifest manifest;
         if ( url.getPath().endsWith( "/" ) )
         {
             final InputStream in = Streams.open( new URL( url, MANIFEST_ENTRY ) );
             try
             {
                 manifest = new Manifest( in );
             }
             finally
             {
                 in.close();
             }
         }
         else if ( "file".equals( url.getProtocol() ) )
         {
             final JarFile jf = new JarFile( FileEntryIterator.toFile( url ) );
             try
             {
                 manifest = jf.getManifest();
             }
             finally
             {
                 jf.close();
             }
         }
         else
         {
             final JarInputStream jin = new JarInputStream( Streams.open( url ) );
             try
             {
                 manifest = jin.getManifest();
             }
             finally
             {
                 jin.close();
             }
         }
         if ( null != manifest )
         {
             final String classPath = manifest.getMainAttributes().getValue( "Class-Path" );
             if ( null != classPath )
             {
                 return classPath.split( " " );
             }
         }
         return EMPTY_CLASSPATH;
     }
 }
	/*******************************************************************************
	* Copyright (c) 2010, 2015 Sonatype, Inc.
	* 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:
	* Stuart McCulloch (Sonatype, Inc.) - initial API and implementation
	*******************************************************************************/
	package org.eclipse.sisu.space;

	import java.io.File;
	import java.io.IOException;
	import java.io.InputStream;
	import java.net.MalformedURLException;
	import java.net.URL;
	import java.net.URLClassLoader;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Collections;
	import java.util.Enumeration;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Set;
	import java.util.jar.JarFile;
	import java.util.jar.JarInputStream;
	import java.util.jar.Manifest;

	import org.eclipse.sisu.inject.DeferredClass;

	/**
	* {@link ClassSpace} backed by a strongly-referenced {@link ClassLoader} and a {@link URL} class path.
	*/
	public class URLClassSpace
	implements ClassSpace
	{
	// ----------------------------------------------------------------------
	// Static initialization
	// ----------------------------------------------------------------------

	static
	{
	ClassLoader systemLoader;
	String classPath;
	try
	{
	systemLoader = ClassLoader.getSystemClassLoader();
	classPath = System.getProperty( "java.class.path", "." );
	}
	catch ( final RuntimeException e )
	{
	systemLoader = null;
	classPath = null;
	}
	catch ( final LinkageError e )
	{
	systemLoader = null;
	classPath = null;
	}
	SYSTEM_LOADER = systemLoader;
	SYSTEM_CLASSPATH = classPath;
	}

	// ----------------------------------------------------------------------
	// Constants
	// ----------------------------------------------------------------------

	private static final String MANIFEST_ENTRY = "META-INF/MANIFEST.MF";

	private static final URL[] NO_URLS = {};

	private static final Enumeration<URL> NO_ENTRIES = Collections.enumeration( Collections.<URL> emptySet() );

	private static final String[] EMPTY_CLASSPATH = {};

	private static final ClassLoader SYSTEM_LOADER;

	private static final String SYSTEM_CLASSPATH;

	// ----------------------------------------------------------------------
	// Implementation fields
	// ----------------------------------------------------------------------

	private final ClassLoader loader;

	private final String pathDetails;

	private URL[] classPath;

	// ----------------------------------------------------------------------
	// Constructors
	// ----------------------------------------------------------------------

	/**
	* Creates a {@link ClassSpace} backed by a {@link ClassLoader} and its default class path.
	* <p>
	* For {@link URLClassLoader}s this is their expanded Class-Path; otherwise it is empty.
	*
	* @param loader The class loader to use when getting/finding resources
	*/
	public URLClassSpace( final ClassLoader loader )
	{
	this.loader = loader;
	pathDetails = null;
	// compute class path on demand
	}

	/**
	* Creates a {@link ClassSpace} backed by a {@link ClassLoader} with a restricted class path.
	*
	* @param loader The class loader to use when getting resources
	* @param path The class path to use when finding resources
	* @see #getResources(String)
	* @see #findEntries(String, String, boolean)
	*/
	public URLClassSpace( final ClassLoader loader, final URL[] path )
	{
	this.loader = loader;
	pathDetails = Arrays.toString( path );
	if ( null != path && path.length > 0 )
	{
	classPath = expandClassPath( path );
	}
	else
	{
	classPath = NO_URLS;
	}
	}

	// ----------------------------------------------------------------------
	// Public methods
	// ----------------------------------------------------------------------

	public final Class<?> loadClass( final String name )
	{
	try
	{
	return loader.loadClass( name );
	}
	catch ( final Exception e )
	{
	throw new TypeNotPresentException( name, e );
	}
	catch ( final LinkageError e )
	{
	throw new TypeNotPresentException( name, e );
	}
	}

	public final DeferredClass<?> deferLoadClass( final String name )
	{
	return new NamedClass<Object>( this, name );
	}

	public final URL getResource( final String name )
	{
	return loader.getResource( name );
	}

	public final Enumeration<URL> getResources( final String name )
	{
	try
	{
	final Enumeration<URL> resources = loader.getResources( name );
	return null != resources ? resources : NO_ENTRIES; // NOSONAR
	}
	catch ( final IOException e )
	{
	return NO_ENTRIES;
	}
	}

	public final Enumeration<URL> findEntries( final String path, final String glob, final boolean recurse )
	{
	return new ResourceEnumeration( path, glob, recurse, getClassPath() );
	}

	public final URL[] getURLs()
	{
	return getClassPath().clone();
	}

	@Override
	public final int hashCode()
	{
	return loader.hashCode(); // the loader is the primary key
	}

	@Override
	public final boolean equals( final Object rhs )
	{
	if ( this == rhs )
	{
	return true;
	}
	if ( rhs instanceof URLClassSpace )
	{
	return loader.equals( ( (URLClassSpace) rhs ).loader );
	}
	return false;
	}

	@Override
	public final String toString()
	{
	return null == pathDetails ? loader.toString() : loader + "(" + pathDetails + ")";
	}

	// ----------------------------------------------------------------------
	// Implementation methods
	// ----------------------------------------------------------------------

	/**
	* Returns the associated {@link URL} class path; this can either be explicit or implicit.
	*/
	private synchronized URL[] getClassPath()
	{
	if ( null == classPath )
	{
	for ( ClassLoader l = loader; l != null; l = l.getParent() )
	{
	if ( l instanceof URLClassLoader )
	{
	// pick first class loader with non-empty class path
	final URL[] path = ( (URLClassLoader) l ).getURLs();
	if ( null != path && path.length > 0 )
	{
	classPath = expandClassPath( path );
	break;
	}
	}
	else if ( null != SYSTEM_LOADER && l == SYSTEM_LOADER )
	{
	classPath = expandClassPath( getSystemClassPath() );
	break;
	}
	}
	if ( null == classPath )
	{
	classPath = NO_URLS; // no detectable Class-Path
	}
	}
	return classPath;
	}

	/**
	* Returns the system {@link URL} class path.
	*/
	private static URL[] getSystemClassPath()
	{
	final String[] paths = SYSTEM_CLASSPATH.split( File.pathSeparator );

	final URL[] urls = new URL[paths.length];
	for ( int i = 0; i < paths.length; i++ )
	{
	try
	{
	urls[i] = ( new File( paths[i] ).toURI().toURL() );
	}
	catch ( final MalformedURLException e )
	{
	urls[i] = null; // ignore malformed class-path entry
	}
	}
	return urls;
	}

	/**
	* Expands the given {@link URL} class path to include Class-Path entries from local manifests.
	*
	* @param classPath The URL class path
	* @return Expanded URL class path
	*/
	private static URL[] expandClassPath( final URL[] classPath )
	{
	final List<URL> searchPath = new ArrayList<URL>();
	Collections.addAll( searchPath, classPath );

	final List<URL> expandedPath = new ArrayList<URL>();
	final Set<String> visited = new HashSet<String>();

	// search path may grow, so use index not iterator
	for ( int i = 0; i < searchPath.size(); i++ )
	{
	final URL url = normalizeEntry( searchPath.get( i ) );
	if ( null == url \|\| !visited.add( url.toString() ) )
	{
	continue; // already processed
	}
	expandedPath.add( url );
	final String[] classPathEntries;
	try
	{
	classPathEntries = getClassPathEntries( url );
	}
	catch ( final IOException e )
	{
	continue; // missing manifest
	}
	for ( final String entry : classPathEntries )
	{
	try
	{
	searchPath.add( new URL( url, entry ) );
	}
	catch ( final MalformedURLException e ) // NOPMD
	{
	// invalid Class-Path entry
	}
	}
	}

	return expandedPath.toArray( new URL[expandedPath.size()] );
	}

	/**
	* Normalizes the given class path entry by removing any extraneous "jar:"..."!/" padding.
	*
	* @param path The URL to normalize
	* @return Normalized class path entry
	*/
	private static URL normalizeEntry( final URL url )
	{
	if ( null != url && "jar".equals( url.getProtocol() ) )
	{
	final String path = url.getPath();
	if ( path.endsWith( "!/" ) )
	{
	try
	{
	return new URL( path.substring( 0, path.length() - 2 ) );
	}
	catch ( final MalformedURLException e )
	{
	// this shouldn't happen, hence illegal state
	throw new IllegalStateException( e.toString() );
	}
	}
	}
	return url;
	}

	/**
	* Looks for Class-Path entries in the given jar or directory; returns empty array if none are found.
	*
	* @param url The jar or directory to inspect
	* @return Array of Class-Path entries
	*/
	private static String[] getClassPathEntries( final URL url )
	throws IOException
	{
	final Manifest manifest;
	if ( url.getPath().endsWith( "/" ) )
	{
	final InputStream in = Streams.open( new URL( url, MANIFEST_ENTRY ) );
	try
	{
	manifest = new Manifest( in );
	}
	finally
	{
	in.close();
	}
	}
	else if ( "file".equals( url.getProtocol() ) )
	{
	final JarFile jf = new JarFile( FileEntryIterator.toFile( url ) );
	try
	{
	manifest = jf.getManifest();
	}
	finally
	{
	jf.close();
	}
	}
	else
	{
	final JarInputStream jin = new JarInputStream( Streams.open( url ) );
	try
	{
	manifest = jin.getManifest();
	}
	finally
	{
	jin.close();
	}
	}
	if ( null != manifest )
	{
	final String classPath = manifest.getMainAttributes().getValue( "Class-Path" );
	if ( null != classPath )
	{
	return classPath.split( " " );
	}
	}
	return EMPTY_CLASSPATH;
	}
	}