contrib/classloader/src/main/java/org/apache/jackrabbit/classloader/ClassLoaderResource.java - jackrabbit - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  The ASF licenses this file to You
  * under the Apache License, Version 2.0 (the "License"); you may not
  * use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.apache.jackrabbit.classloader;

 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
 import java.security.cert.Certificate;
 import java.util.Date;
 import java.util.jar.Manifest;

 import javax.jcr.Property;
 import javax.jcr.RepositoryException;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.jackrabbit.net.URLFactory;


 /**
  * The <code>ClassLoaderResource</code> class represents a resource looked up
  * by the {@link ClassPathEntry}s of the {@link RepositoryClassLoader}. The
  * class provides transparent access to the resource irrespective of the fact
  * on whether the resource is contained in a repository property or in an
  * JAR or ZIP archive.
  * <p>
  * This class is extended to implement depending features such as storing
  * resources in repository properties or JAR or ZIP archives.
  *
  * @author Felix Meschberger
  */
 class ClassLoaderResource {

     /** default log category */
     private static final Log log = LogFactory.getLog(ClassLoaderResource.class);

     /**
      * The class path entry which loaded this class loader resource
      */
     private final ClassPathEntry pathEntry;

     /**
      * The name of this resource.
      */
     private final String name;

     /**
      * The repository property providing the resource's contents. This may be
      * <code>null</code> if the resource was loaded from a JAR/ZIP archive.
      */
     private final Property resProperty;

     /**
      * The class optionally loaded/defined through this resource.
      *
      * @see #getLoadedClass()
      * @see #setLoadedClass(Class)
      */
     private Class loadedClass;

     /**
      * The time in milliseconds at which this resource has been loaded from
      * the repository.
      */
     private final long loadTime;

     /**
      * Creates an instance of this class for the class path entry.
      *
      * @param pathEntry The {@link ClassPathEntry} of the code source of this
      *      class loader resource.
      * @param name The path name of this resource.
      * @param resProperty The <code>Property</code>providing the content's of
      *      this resource. This may be <code>null</code> if the resource
      *      was loaded from an JAR or ZIP archive.
      */
     /* package */ ClassLoaderResource(ClassPathEntry pathEntry, String name,
             Property resProperty) {
         this.pathEntry = pathEntry;
         this.name = name;
         this.resProperty = resProperty;
         this.loadTime = System.currentTimeMillis();
     }

     /**
      * Returns the {@link ClassPathEntry} which loaded this resource.
      */
     protected ClassPathEntry getClassPathEntry() {
         return pathEntry;
     }

     /**
      * Returns the name of this resource. This is the name used to find the
      * resource, for example the class name or the properties file path.
      */
     public String getName() {
         return name;
     }

     /**
      * Returns the <code>Property</code> with which this resource is created.
      */
     protected Property getProperty() {
         return resProperty;
     }

     /**
      * Returns the time in milliseconds at which this resource has been loaded
      */
     protected long getLoadTime() {
         return loadTime;
     }

     /**
      * Returns the URL to access this resource, for example a JCR or a JAR URL.
      * If the URL cannot be created from the resource data, <code>null</code> is
      * returned.
      */
     public URL getURL() {
         try {
             return URLFactory.createURL(getClassPathEntry().session, getPath());
         } catch (Exception e) {
             log.warn("getURL: Cannot getURL for " + getPath(), e);
         }
         return null;
     }

     /**
      * Returns the URL to the code source of this entry. If there is no code
      * source available, <code>null</code> is returned.
      * <p>
      * This base class implementation returns the result of calling
      * {@link ClassPathEntry#toURL()} on the class path entry from which this
      * resource was loaded.
      */
     public URL getCodeSourceURL() {
         return getClassPathEntry().toURL();
     }

     /**
      * Returns an <code>InputStream</code> to read from the resource.
      * <p>
      * This base class implementation returns the result of calling the
      * <code>getStream()</code> method on the resource's property or
      * <code>null</code> if the property is not set.
      */
     public InputStream getInputStream() throws RepositoryException {
         return (getProperty() != null) ? getProperty().getStream() : null;
     }

     /**
      * Returns the size of the resource or -1 if the size cannot be found out.
      * <p>
      * This base class implementation returns the result of calling the
      * <code>getLength()</code> method on the resource's property or -1 if
      * the property is not set.
      *
      * @throws RepositoryException If an error occurrs trying to find the length
      *      of the property.
      */
     public int getContentLength() throws RepositoryException {
         return (getProperty() != null) ? (int) getProperty().getLength() : -1;
     }

     /**
      * Returns the path of the property containing the resource.
      * <p>
      * This base class implementation returns the absolute path of the
      * resource's property. If the property is not set or if an error occurrs
      * accesing the property's path, the concatentation of the class path
      * entry's path and the resource's name is returned.
      */
     public String getPath() {
         if (getProperty() != null) {
             try {
                 return getProperty().getPath();
             } catch (RepositoryException re) {
                 // fallback
                 log.warn("getPath: Cannot retrieve path of entry " + getName(),
                     re);
             }
         }

         // fallback if no resource property or an error accessing the path of
         // the property
         return getClassPathEntry().getPath() + getName();
     }

     /**
      * Returns the time of the the last modification of the resource or -1 if
      * the last modification time cannot be evaluated.
      * <p>
      * This base class implementation returns the result of calling the
      * {@link Util#getLastModificationTime(Property)} method on the resource's
      * property if not <code>null</code>. In case of an error or if the
      * property is <code>null</code>, -1 is returned.
      */
     public long getLastModificationTime() {
         if (getProperty() != null) {
             try {
                 return Util.getLastModificationTime(getProperty());
             } catch (RepositoryException re) {
                 log.info("getLastModificationTime of resource property", re);
             }
         }

         // cannot find the resource modification time, use epoch
         return -1;
     }

     /**
      * Returns the resource as an array of bytes
      */
     public byte[] getBytes() throws IOException, RepositoryException {
         InputStream in = null;
         byte[] buf = null;

         log.debug("getBytes");

         try {
             in = getInputStream();
             log.debug("getInputStream() returned " + in);

             int length = getContentLength();
             log.debug("getContentLength() returned " + String.valueOf(length));

             if (length >= 0) {

                 buf = new byte[length];
                 for (int read; length > 0; length -= read) {
                     read = in.read(buf, buf.length - length, length);
                     if (read == -1) {
                         throw new IOException("unexpected EOF");
                     }
                 }

             } else {

                 buf = new byte[1024];
                 int count = 0;
                 int read;

                 // read enlarging buffer
                 while ((read = in.read(buf, count, buf.length - count)) != -1) {
                     count += read;
                     if (count >= buf.length) {
                         byte buf1[] = new byte[count * 2];
                         System.arraycopy(buf, 0, buf1, 0, count);
                         buf = buf1;
                     }
                 }

                 // resize buffer if too big
                 if (count != buf.length) {
                     byte buf1[] = new byte[count];
                     System.arraycopy(buf, 0, buf1, 0, count);
                     buf = buf1;
                 }

             }

         } finally {

             if (in != null) {
                 try {
                     in.close();
                 } catch (IOException ignore) {
                 }
             }

         }

         return buf;
     }

     /**
      * Returns the manifest from the jar file for this class resource. If this
      * resource is not from a jar file, the method returns <code>null</code>,
      * which is what the default implementation does.
      */
     public Manifest getManifest() {
         return null;
     }

     /**
      * Returns the certificates from the jar file for this class resource. If
      * this resource is not from a jar file, the method returns
      * <code>null</code>, which is what the default implementation does.
      */
     public Certificate[] getCertificates() {
         return null;
     }

     /**
      * Returns the <code>Property</code> which is used to check whether this
      * resource is expired or not.
      * <p>
      * This base class method returns the same property as returned by the
      * {@link #getProperty()} method. This method may be overwritten by
      * implementations as appropriate.
      *
      * @see #isExpired()
      */
     protected Property getExpiryProperty() {
         return getProperty();
     }

     /**
      * Returns <code>true</code> if the last modification date of the expiry
      * property of this resource is loaded is later than the time at which this
      * resource has been loaded. If the last modification time of the expiry
      * property cannot be calculated or if an error occurrs checking the expiry
      * propertiy's last modification time, <code>true</code> is returned.
      */
     public boolean isExpired() {
         try {
             // creation time of version if loaded now
             long currentPropTime = 0;
             Property prop = getExpiryProperty();
             if (prop != null) {
                 currentPropTime = Util.getLastModificationTime(prop);
             }

             // creation time of version currently loaded
             long loadTime = getLoadTime();

             // expire if a new version would be loaded
             boolean exp = currentPropTime > loadTime;
             if (exp && log.isDebugEnabled()) {
                 log.debug("expireResource: Resource created " +
                     new Date(loadTime) + " superceded by version created " +
                     new Date(currentPropTime));
             }

             // return the result of checking
             return exp;
         } catch (RepositoryException re) {
             log.debug("expireResource: Cannot get current version for " +
                 toString() + ", will expire: " + re);
             return true;
         }
     }

     /**
      * Returns the class which was loaded through this resource. It is expected
      * that the class loader sets the class which was loaded through this
      * resource by calling the {@link #setLoadedClass(Class)} method. If this
      * class was not used to load a class or if the class loader failed to
      * set the class loaded through this resoource, this method will return
      * <code>null</code>.
      *
      * @return The class loaded through this resource, which may be
      *      <code>null</code> if this resource was never used to load a class
      *      or if the loader failed to set class through the
      *      {@link #setLoadedClass(Class)} method.
      *
      * @see #setLoadedClass(Class)
      */
     public Class getLoadedClass() {
         return loadedClass;
     }

     /**
      * Sets the class which was loaded through this resource. This method does
      * not check, whether it is plausible that this class was actually loaded
      * from this resource, nor does this method check whether the class object
      * is <code>null</code> or not.
      *
      * @param loadedClass The class to be loaded.
      */
     public void setLoadedClass(Class loadedClass) {
         this.loadedClass = loadedClass;
     }

     /**
      * Returns the <code>String</code> representation of this resource.
      */
     public String toString() {
         StringBuffer buf = new StringBuffer(getClass().getName());
         buf.append(": path=");
         buf.append(getPath());
         buf.append(", name=");
         buf.append(getName());
         return buf.toString();
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. The ASF licenses this file to You
	* under the Apache License, Version 2.0 (the "License"); you may not
	* use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package org.apache.jackrabbit.classloader;

	import java.io.IOException;
	import java.io.InputStream;
	import java.net.URL;
	import java.security.cert.Certificate;
	import java.util.Date;
	import java.util.jar.Manifest;

	import javax.jcr.Property;
	import javax.jcr.RepositoryException;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;
	import org.apache.jackrabbit.net.URLFactory;


	/**
	* The <code>ClassLoaderResource</code> class represents a resource looked up
	* by the {@link ClassPathEntry}s of the {@link RepositoryClassLoader}. The
	* class provides transparent access to the resource irrespective of the fact
	* on whether the resource is contained in a repository property or in an
	* JAR or ZIP archive.
	* <p>
	* This class is extended to implement depending features such as storing
	* resources in repository properties or JAR or ZIP archives.
	*
	* @author Felix Meschberger
	*/
	class ClassLoaderResource {

	/** default log category */
	private static final Log log = LogFactory.getLog(ClassLoaderResource.class);

	/**
	* The class path entry which loaded this class loader resource
	*/
	private final ClassPathEntry pathEntry;

	/**
	* The name of this resource.
	*/
	private final String name;

	/**
	* The repository property providing the resource's contents. This may be
	* <code>null</code> if the resource was loaded from a JAR/ZIP archive.
	*/
	private final Property resProperty;

	/**
	* The class optionally loaded/defined through this resource.
	*
	* @see #getLoadedClass()
	* @see #setLoadedClass(Class)
	*/
	private Class loadedClass;

	/**
	* The time in milliseconds at which this resource has been loaded from
	* the repository.
	*/
	private final long loadTime;

	/**
	* Creates an instance of this class for the class path entry.
	*
	* @param pathEntry The {@link ClassPathEntry} of the code source of this
	* class loader resource.
	* @param name The path name of this resource.
	* @param resProperty The <code>Property</code>providing the content's of
	* this resource. This may be <code>null</code> if the resource
	* was loaded from an JAR or ZIP archive.
	*/
	/* package */ ClassLoaderResource(ClassPathEntry pathEntry, String name,
	Property resProperty) {
	this.pathEntry = pathEntry;
	this.name = name;
	this.resProperty = resProperty;
	this.loadTime = System.currentTimeMillis();
	}

	/**
	* Returns the {@link ClassPathEntry} which loaded this resource.
	*/
	protected ClassPathEntry getClassPathEntry() {
	return pathEntry;
	}

	/**
	* Returns the name of this resource. This is the name used to find the
	* resource, for example the class name or the properties file path.
	*/
	public String getName() {
	return name;
	}

	/**
	* Returns the <code>Property</code> with which this resource is created.
	*/
	protected Property getProperty() {
	return resProperty;
	}

	/**
	* Returns the time in milliseconds at which this resource has been loaded
	*/
	protected long getLoadTime() {
	return loadTime;
	}

	/**
	* Returns the URL to access this resource, for example a JCR or a JAR URL.
	* If the URL cannot be created from the resource data, <code>null</code> is
	* returned.
	*/
	public URL getURL() {
	try {
	return URLFactory.createURL(getClassPathEntry().session, getPath());
	} catch (Exception e) {
	log.warn("getURL: Cannot getURL for " + getPath(), e);
	}
	return null;
	}

	/**
	* Returns the URL to the code source of this entry. If there is no code
	* source available, <code>null</code> is returned.
	* <p>
	* This base class implementation returns the result of calling
	* {@link ClassPathEntry#toURL()} on the class path entry from which this
	* resource was loaded.
	*/
	public URL getCodeSourceURL() {
	return getClassPathEntry().toURL();
	}

	/**
	* Returns an <code>InputStream</code> to read from the resource.
	* <p>
	* This base class implementation returns the result of calling the
	* <code>getStream()</code> method on the resource's property or
	* <code>null</code> if the property is not set.
	*/
	public InputStream getInputStream() throws RepositoryException {
	return (getProperty() != null) ? getProperty().getStream() : null;
	}

	/**
	* Returns the size of the resource or -1 if the size cannot be found out.
	* <p>
	* This base class implementation returns the result of calling the
	* <code>getLength()</code> method on the resource's property or -1 if
	* the property is not set.
	*
	* @throws RepositoryException If an error occurrs trying to find the length
	* of the property.
	*/
	public int getContentLength() throws RepositoryException {
	return (getProperty() != null) ? (int) getProperty().getLength() : -1;
	}

	/**
	* Returns the path of the property containing the resource.
	* <p>
	* This base class implementation returns the absolute path of the
	* resource's property. If the property is not set or if an error occurrs
	* accesing the property's path, the concatentation of the class path
	* entry's path and the resource's name is returned.
	*/
	public String getPath() {
	if (getProperty() != null) {
	try {
	return getProperty().getPath();
	} catch (RepositoryException re) {
	// fallback
	log.warn("getPath: Cannot retrieve path of entry " + getName(),
	re);
	}
	}

	// fallback if no resource property or an error accessing the path of
	// the property
	return getClassPathEntry().getPath() + getName();
	}

	/**
	* Returns the time of the the last modification of the resource or -1 if
	* the last modification time cannot be evaluated.
	* <p>
	* This base class implementation returns the result of calling the
	* {@link Util#getLastModificationTime(Property)} method on the resource's
	* property if not <code>null</code>. In case of an error or if the
	* property is <code>null</code>, -1 is returned.
	*/
	public long getLastModificationTime() {
	if (getProperty() != null) {
	try {
	return Util.getLastModificationTime(getProperty());
	} catch (RepositoryException re) {
	log.info("getLastModificationTime of resource property", re);
	}
	}

	// cannot find the resource modification time, use epoch
	return -1;
	}

	/**
	* Returns the resource as an array of bytes
	*/
	public byte[] getBytes() throws IOException, RepositoryException {
	InputStream in = null;
	byte[] buf = null;

	log.debug("getBytes");

	try {
	in = getInputStream();
	log.debug("getInputStream() returned " + in);

	int length = getContentLength();
	log.debug("getContentLength() returned " + String.valueOf(length));

	if (length >= 0) {

	buf = new byte[length];
	for (int read; length > 0; length -= read) {
	read = in.read(buf, buf.length - length, length);
	if (read == -1) {
	throw new IOException("unexpected EOF");
	}
	}

	} else {

	buf = new byte[1024];
	int count = 0;
	int read;

	// read enlarging buffer
	while ((read = in.read(buf, count, buf.length - count)) != -1) {
	count += read;
	if (count >= buf.length) {
	byte buf1[] = new byte[count * 2];
	System.arraycopy(buf, 0, buf1, 0, count);
	buf = buf1;
	}
	}

	// resize buffer if too big
	if (count != buf.length) {
	byte buf1[] = new byte[count];
	System.arraycopy(buf, 0, buf1, 0, count);
	buf = buf1;
	}

	}

	} finally {

	if (in != null) {
	try {
	in.close();
	} catch (IOException ignore) {
	}
	}

	}

	return buf;
	}

	/**
	* Returns the manifest from the jar file for this class resource. If this
	* resource is not from a jar file, the method returns <code>null</code>,
	* which is what the default implementation does.
	*/
	public Manifest getManifest() {
	return null;
	}

	/**
	* Returns the certificates from the jar file for this class resource. If
	* this resource is not from a jar file, the method returns
	* <code>null</code>, which is what the default implementation does.
	*/
	public Certificate[] getCertificates() {
	return null;
	}

	/**
	* Returns the <code>Property</code> which is used to check whether this
	* resource is expired or not.
	* <p>
	* This base class method returns the same property as returned by the
	* {@link #getProperty()} method. This method may be overwritten by
	* implementations as appropriate.
	*
	* @see #isExpired()
	*/
	protected Property getExpiryProperty() {
	return getProperty();
	}

	/**
	* Returns <code>true</code> if the last modification date of the expiry
	* property of this resource is loaded is later than the time at which this
	* resource has been loaded. If the last modification time of the expiry
	* property cannot be calculated or if an error occurrs checking the expiry
	* propertiy's last modification time, <code>true</code> is returned.
	*/
	public boolean isExpired() {
	try {
	// creation time of version if loaded now
	long currentPropTime = 0;
	Property prop = getExpiryProperty();
	if (prop != null) {
	currentPropTime = Util.getLastModificationTime(prop);
	}

	// creation time of version currently loaded
	long loadTime = getLoadTime();

	// expire if a new version would be loaded
	boolean exp = currentPropTime > loadTime;
	if (exp && log.isDebugEnabled()) {
	log.debug("expireResource: Resource created " +
	new Date(loadTime) + " superceded by version created " +
	new Date(currentPropTime));
	}

	// return the result of checking
	return exp;
	} catch (RepositoryException re) {
	log.debug("expireResource: Cannot get current version for " +
	toString() + ", will expire: " + re);
	return true;
	}
	}

	/**
	* Returns the class which was loaded through this resource. It is expected
	* that the class loader sets the class which was loaded through this
	* resource by calling the {@link #setLoadedClass(Class)} method. If this
	* class was not used to load a class or if the class loader failed to
	* set the class loaded through this resoource, this method will return
	* <code>null</code>.
	*
	* @return The class loaded through this resource, which may be
	* <code>null</code> if this resource was never used to load a class
	* or if the loader failed to set class through the
	* {@link #setLoadedClass(Class)} method.
	*
	* @see #setLoadedClass(Class)
	*/
	public Class getLoadedClass() {
	return loadedClass;
	}

	/**
	* Sets the class which was loaded through this resource. This method does
	* not check, whether it is plausible that this class was actually loaded
	* from this resource, nor does this method check whether the class object
	* is <code>null</code> or not.
	*
	* @param loadedClass The class to be loaded.
	*/
	public void setLoadedClass(Class loadedClass) {
	this.loadedClass = loadedClass;
	}

	/**
	* Returns the <code>String</code> representation of this resource.
	*/
	public String toString() {
	StringBuffer buf = new StringBuffer(getClass().getName());
	buf.append(": path=");
	buf.append(getPath());
	buf.append(", name=");
	buf.append(getName());
	return buf.toString();
	}
	}