ldap/src/main/java/org/apache/directory/shared/ldap/message/spi/Provider.java - directory-ldap-api - Git at Google

 /*
  *  Licensed to the Apache Software Foundation (ASF) under one
  *  or more contributor license agreements.  See the NOTICE file
  *  distributed with this work for additional information
  *  regarding copyright ownership.  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.directory.shared.ldap.message.spi;


 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.Hashtable;
 import java.util.Properties;

 import org.apache.directory.shared.i18n.I18n;
 import org.apache.directory.shared.ldap.codec.LdapProvider;


 /**
  * Abstract Provider base class and factory for accessing berlib specific
  * Provider implementations and their SPI implementation classes.
  *
  * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
  */
 public abstract class Provider
 {
     /** Default BER Library provider class name */
     public static final String DEFAULT_PROVIDER = LdapProvider.class.getName();

     /** BER Library provider class name property */
     public static final String BERLIB_PROVIDER = "asn.1.berlib.provider";

     /** The default file searched for on CP to load default provider props. */
     public static final String BERLIB_PROPFILE = "berlib.properties";

     /** A provider monitor key. */
     public static final String PROVIDER_MONITOR_KEY = "asn.1.berlib.provider.monitor";

     /** Message to use when using defaults */
     public static final String USING_DEFAULTS_MSG = "Could not find the ASN.1 berlib provider properties file: "
         + "berlib.properties.\nFile is not present on the classpath " + "or in $JAVA_HOME/lib:\n\tjava.home = "
         + System.getProperty( "java.home" ) + "\n\tjava.class.path = " + System.getProperty( "java.class.path" );

     /** Use the no-op monitor by default unless we find something else */
     private static ProviderMonitor monitor;

     static
     {
         findMonitor( System.getProperties() );
     }


     /*
      * Checks to see if the provider monitor has been set as a system property.
      * If it has try to instantiate it and use it.
      */
     private static void findMonitor( Properties props )
     {
         if ( props.containsKey( PROVIDER_MONITOR_KEY ) )
         {
             String fqcn = System.getProperties().getProperty( PROVIDER_MONITOR_KEY );

             if ( fqcn != null )
             {
                 Class<?> mc;

                 try
                 {
                     mc = Class.forName( fqcn );
                     monitor = ( ProviderMonitor ) mc.newInstance();
                 }
                 catch ( ClassNotFoundException e )
                 {
                     System.err.println( I18n.err( I18n.ERR_04177, fqcn ) );
                 }
                 catch ( IllegalAccessException e )
                 {
                     System.err.println( I18n.err( I18n.ERR_04178, fqcn ) );
                 }
                 catch ( InstantiationException e )
                 {
                     System.err.println( I18n.err( I18n.ERR_04179, fqcn ) );
                 }
             }
         }

         if ( monitor == null )
         {
             monitor = ProviderMonitor.NOOP_MONITOR;
         }
     }

     // ------------------------------------------------------------------------
     // Provider Properties
     // ------------------------------------------------------------------------

     /** The descriptive string to identify this provider */
     private final String name;

     /** The Provider's vendor name */
     private final String vendor;


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

     /**
      * Creates an instance of a Provider.
      *
      * @param name
      *            a descriptive name for a provider
      * @param vendor
      *            the berlib vendor used by the provider
      */
     protected Provider( String name, String vendor )
     {
         this.name = name;
         this.vendor = vendor;
     }


     // ------------------------------------------------------------------------
     // Property Accessor Methods
     // ------------------------------------------------------------------------

     /**
      * Gets the descriptive name for this Provider.
      *
      * @return the Provider's name.
      */
     public final String getName()
     {
         return name;
     }


     /**
      * Gets this Providers vendor name if it was provided.
      *
      * @return the vendor name for this provider or the String 'UNKNOWN' if it
      *         is not known.
      */
     public final String getVendor()
     {
         return vendor;
     }


     /**
      * Gets the encoder associated with this provider.
      *
      * @return the provider's encoder.
      * @throws ProviderException
      *             if the provider or its encoder cannot be found
      */
     public abstract ProviderEncoder getEncoder() throws ProviderException;


     /**
      * Gets the decoder associated with this provider.
      *
      * @return the provider's decoder.
      * @throws ProviderException if the provider or its decoder cannot be found
      * @param binaryAttributeDetector detects whether or not attributes are binary
      * @param maxPDUSize the maximum size a PDU can be
      */
     public abstract ProviderDecoder getDecoder( BinaryAttributeDetector binaryAttributeDetector,
         int maxPDUSize )
             throws ProviderException;


     // ------------------------------------------------------------------------
     // Factory/Environment Methods
     // ------------------------------------------------------------------------


     /**
      * Gets an instance of the configured Provider. The configured provider is
      * the classname specified by the <code>asn.1.berlib.provider</code>
      * property. The property is searched for within berlib.properties files
      * that are on the java.class.path. If at least one berlib.properties is not
      * found the default provider is used. The resultant value (default or
      * otherwise) for the property can be overridden by command line properties.
      *
      * @return a singleton instance of the configured ASN.1 BER Library Provider
      * @throws ProviderException
      *             if the provider cannot be found
      */
     public static Provider getProvider() throws ProviderException
     {
         return getProvider( getEnvironment() );
     }


     /**
      * Gets an instance of the Provider specified by the <code>
      * asn.1.berlib.provider</code>
      * property value. The property is searched for within properties object
      * passed in as a parameter for this method only.
      *
      * @param env
      *            the environment used to locate the provider
      * @return a singleton instance of the ASN.1 BER Library Provider
      * @throws ProviderException
      *             if the provider cannot be found
      */
     public static Provider getProvider( Hashtable<Object, Object> env ) throws ProviderException
     {
         Provider provider;
         String className = ( String ) env.get( BERLIB_PROVIDER );

         // --------------------------------------------------------------------
         // Check for a valid property value
         // --------------------------------------------------------------------
         if ( ( className == null ) || className.trim().equals( "" ) )
         {
             throw new ProviderException( null, I18n.err( I18n.ERR_04180, BERLIB_PROVIDER ) );
         }

         try
         {
             Class<?> clazz = Class.forName( className );
             Method method = clazz.getMethod( "getProvider", (Class[])null );
             provider = ( Provider ) method.invoke( null, (Object[])null );
         }
         catch ( ClassNotFoundException cnfe )
         {
             ProviderException pe = new ProviderException( null, I18n.err( I18n.ERR_04181, className ) );
             pe.addThrowable( cnfe );
             throw pe;
         }
         catch ( NoSuchMethodException nsme )
         {
             ProviderException pe = new ProviderException( null, I18n.err( I18n.ERR_04182, className ) );
             pe.addThrowable( nsme );
             throw pe;
         }
         catch ( IllegalAccessException iae )
         {
             ProviderException pe = new ProviderException( null, I18n.err( I18n.ERR_04183, className ) );
             pe.addThrowable( iae );
             throw pe;
         }
         catch ( InvocationTargetException ite )
         {
             ProviderException pe = new ProviderException( null, I18n.err( I18n.ERR_04184, className, ite.getTargetException() ) );
             pe.addThrowable( ite.getTargetException() );
             throw pe;
         }

         return provider;
     }


     /**
      * Loads the properties for the effective environment. First searches class
      * path for the default berlib.properties file. If it cannot find the file
      * on the classpath it loads the defaults in the default berlib.properties
      * file found in $JAVA_HOME/lib/berlib.properties. If the default file is
      * not found and no berlib.properties are found on the classpath then the
      * default provider is used. Once the property is set overriding values are
      * searched for in the System's properties specified at startup using the
      * <code>-Dproperty=value</code><i>java</i> command-line arguments.
      *
      * @return the environment properties TODO why are we not throwing
      *         ProviderExceptions here?
      */
     public static Properties getEnvironment()
     {
         // Prop file not on classpath so we complain and use the default!
         Properties env = new Properties();
         env.setProperty( BERLIB_PROVIDER, DEFAULT_PROVIDER );
         monitor.usingDefaults( USING_DEFAULTS_MSG, env );
         return env;
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. 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.directory.shared.ldap.message.spi;


	import java.lang.reflect.InvocationTargetException;
	import java.lang.reflect.Method;
	import java.util.Hashtable;
	import java.util.Properties;

	import org.apache.directory.shared.i18n.I18n;
	import org.apache.directory.shared.ldap.codec.LdapProvider;


	/**
	* Abstract Provider base class and factory for accessing berlib specific
	* Provider implementations and their SPI implementation classes.
	*
	* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
	*/
	public abstract class Provider
	{
	/** Default BER Library provider class name */
	public static final String DEFAULT_PROVIDER = LdapProvider.class.getName();

	/** BER Library provider class name property */
	public static final String BERLIB_PROVIDER = "asn.1.berlib.provider";

	/** The default file searched for on CP to load default provider props. */
	public static final String BERLIB_PROPFILE = "berlib.properties";

	/** A provider monitor key. */
	public static final String PROVIDER_MONITOR_KEY = "asn.1.berlib.provider.monitor";

	/** Message to use when using defaults */
	public static final String USING_DEFAULTS_MSG = "Could not find the ASN.1 berlib provider properties file: "
	+ "berlib.properties.\nFile is not present on the classpath " + "or in $JAVA_HOME/lib:\n\tjava.home = "
	+ System.getProperty( "java.home" ) + "\n\tjava.class.path = " + System.getProperty( "java.class.path" );

	/** Use the no-op monitor by default unless we find something else */
	private static ProviderMonitor monitor;

	static
	{
	findMonitor( System.getProperties() );
	}


	/*
	* Checks to see if the provider monitor has been set as a system property.
	* If it has try to instantiate it and use it.
	*/
	private static void findMonitor( Properties props )
	{
	if ( props.containsKey( PROVIDER_MONITOR_KEY ) )
	{
	String fqcn = System.getProperties().getProperty( PROVIDER_MONITOR_KEY );

	if ( fqcn != null )
	{
	Class<?> mc;

	try
	{
	mc = Class.forName( fqcn );
	monitor = ( ProviderMonitor ) mc.newInstance();
	}
	catch ( ClassNotFoundException e )
	{
	System.err.println( I18n.err( I18n.ERR_04177, fqcn ) );
	}
	catch ( IllegalAccessException e )
	{
	System.err.println( I18n.err( I18n.ERR_04178, fqcn ) );
	}
	catch ( InstantiationException e )
	{
	System.err.println( I18n.err( I18n.ERR_04179, fqcn ) );
	}
	}
	}

	if ( monitor == null )
	{
	monitor = ProviderMonitor.NOOP_MONITOR;
	}
	}

	// ------------------------------------------------------------------------
	// Provider Properties
	// ------------------------------------------------------------------------

	/** The descriptive string to identify this provider */
	private final String name;

	/** The Provider's vendor name */
	private final String vendor;


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

	/**
	* Creates an instance of a Provider.
	*
	* @param name
	* a descriptive name for a provider
	* @param vendor
	* the berlib vendor used by the provider
	*/
	protected Provider( String name, String vendor )
	{
	this.name = name;
	this.vendor = vendor;
	}


	// ------------------------------------------------------------------------
	// Property Accessor Methods
	// ------------------------------------------------------------------------

	/**
	* Gets the descriptive name for this Provider.
	*
	* @return the Provider's name.
	*/
	public final String getName()
	{
	return name;
	}


	/**
	* Gets this Providers vendor name if it was provided.
	*
	* @return the vendor name for this provider or the String 'UNKNOWN' if it
	* is not known.
	*/
	public final String getVendor()
	{
	return vendor;
	}


	/**
	* Gets the encoder associated with this provider.
	*
	* @return the provider's encoder.
	* @throws ProviderException
	* if the provider or its encoder cannot be found
	*/
	public abstract ProviderEncoder getEncoder() throws ProviderException;


	/**
	* Gets the decoder associated with this provider.
	*
	* @return the provider's decoder.
	* @throws ProviderException if the provider or its decoder cannot be found
	* @param binaryAttributeDetector detects whether or not attributes are binary
	* @param maxPDUSize the maximum size a PDU can be
	*/
	public abstract ProviderDecoder getDecoder( BinaryAttributeDetector binaryAttributeDetector,
	int maxPDUSize )
	throws ProviderException;


	// ------------------------------------------------------------------------
	// Factory/Environment Methods
	// ------------------------------------------------------------------------


	/**
	* Gets an instance of the configured Provider. The configured provider is
	* the classname specified by the <code>asn.1.berlib.provider</code>
	* property. The property is searched for within berlib.properties files
	* that are on the java.class.path. If at least one berlib.properties is not
	* found the default provider is used. The resultant value (default or
	* otherwise) for the property can be overridden by command line properties.
	*
	* @return a singleton instance of the configured ASN.1 BER Library Provider
	* @throws ProviderException
	* if the provider cannot be found
	*/
	public static Provider getProvider() throws ProviderException
	{
	return getProvider( getEnvironment() );
	}


	/**
	* Gets an instance of the Provider specified by the <code>
	* asn.1.berlib.provider</code>
	* property value. The property is searched for within properties object
	* passed in as a parameter for this method only.
	*
	* @param env
	* the environment used to locate the provider
	* @return a singleton instance of the ASN.1 BER Library Provider
	* @throws ProviderException
	* if the provider cannot be found
	*/
	public static Provider getProvider( Hashtable<Object, Object> env ) throws ProviderException
	{
	Provider provider;
	String className = ( String ) env.get( BERLIB_PROVIDER );

	// --------------------------------------------------------------------
	// Check for a valid property value
	// --------------------------------------------------------------------
	if ( ( className == null ) \|\| className.trim().equals( "" ) )
	{
	throw new ProviderException( null, I18n.err( I18n.ERR_04180, BERLIB_PROVIDER ) );
	}

	try
	{
	Class<?> clazz = Class.forName( className );
	Method method = clazz.getMethod( "getProvider", (Class[])null );
	provider = ( Provider ) method.invoke( null, (Object[])null );
	}
	catch ( ClassNotFoundException cnfe )
	{
	ProviderException pe = new ProviderException( null, I18n.err( I18n.ERR_04181, className ) );
	pe.addThrowable( cnfe );
	throw pe;
	}
	catch ( NoSuchMethodException nsme )
	{
	ProviderException pe = new ProviderException( null, I18n.err( I18n.ERR_04182, className ) );
	pe.addThrowable( nsme );
	throw pe;
	}
	catch ( IllegalAccessException iae )
	{
	ProviderException pe = new ProviderException( null, I18n.err( I18n.ERR_04183, className ) );
	pe.addThrowable( iae );
	throw pe;
	}
	catch ( InvocationTargetException ite )
	{
	ProviderException pe = new ProviderException( null, I18n.err( I18n.ERR_04184, className, ite.getTargetException() ) );
	pe.addThrowable( ite.getTargetException() );
	throw pe;
	}

	return provider;
	}


	/**
	* Loads the properties for the effective environment. First searches class
	* path for the default berlib.properties file. If it cannot find the file
	* on the classpath it loads the defaults in the default berlib.properties
	* file found in $JAVA_HOME/lib/berlib.properties. If the default file is
	* not found and no berlib.properties are found on the classpath then the
	* default provider is used. Once the property is set overriding values are
	* searched for in the System's properties specified at startup using the
	* <code>-Dproperty=value</code><i>java</i> command-line arguments.
	*
	* @return the environment properties TODO why are we not throwing
	* ProviderExceptions here?
	*/
	public static Properties getEnvironment()
	{
	// Prop file not on classpath so we complain and use the default!
	Properties env = new Properties();
	env.setProperty( BERLIB_PROVIDER, DEFAULT_PROVIDER );
	monitor.usingDefaults( USING_DEFAULTS_MSG, env );
	return env;
	}
	}