org.apache.xalan.extensions
Class ObjectFactory

java.lang.Object
  org.apache.xalan.extensions.ObjectFactory

final class ObjectFactory
extends java.lang.Object

This class is duplicated for each JAXP subpackage so keep it in sync. It is package private and therefore is not exposed as part of the JAXP API.

This code is designed to implement the JAXP 1.1 spec pluggability feature and is designed to run on JDK version 1.1 and later, and to compile on JDK 1.2 and onward. The code also runs both as part of an unbundled jar file and when bundled as part of the JDK.

This class was moved from the javax.xml.parsers.ObjectFactory class and modified to be used as a general utility for creating objects dynamically.

Nested Class Summary

(package private) static class

ObjectFactory.ConfigurationError A configuration error.

Field Summary

private static boolean	DEBUG Set to true for debugging
private static java.lang.String	DEFAULT_PROPERTIES_FILENAME
private static long	fLastModified Cache the time stamp of the xalan.properties file so that we know if it's been modified and can invalidate the cache when necessary.
private static java.util.Properties	fXalanProperties cache the contents of the xalan.properties file.
private static java.lang.String	SERVICES_PATH

Constructor Summary

ObjectFactory()

Method Summary

(package private) static java.lang.Object	createObject(java.lang.String factoryId, java.lang.String fallbackClassName) Finds the implementation Class object in the specified order.
(package private) static java.lang.Object	createObject(java.lang.String factoryId, java.lang.String propertiesFilename, java.lang.String fallbackClassName) Finds the implementation Class object in the specified order.
private static void	debugPrintln(java.lang.String msg) Prints a message to standard error if debugging is enabled.
(package private) static java.lang.ClassLoader	findClassLoader() Figure out which ClassLoader to use.
private static java.lang.String	findJarServiceProviderName(java.lang.String factoryId) Find the name of service provider using Jar Service Provider Mechanism
(package private) static java.lang.Class	findProviderClass(java.lang.String className, java.lang.ClassLoader cl, boolean doFallback) Find a Class using the specified ClassLoader
(package private) static java.lang.Class	lookUpFactoryClass(java.lang.String factoryId) Finds the implementation Class object in the specified order.
(package private) static java.lang.Class	lookUpFactoryClass(java.lang.String factoryId, java.lang.String propertiesFilename, java.lang.String fallbackClassName) Finds the implementation Class object in the specified order.
(package private) static java.lang.String	lookUpFactoryClassName(java.lang.String factoryId, java.lang.String propertiesFilename, java.lang.String fallbackClassName) Finds the name of the required implementation class in the specified order.
(package private) static java.lang.Object	newInstance(java.lang.String className, java.lang.ClassLoader cl, boolean doFallback) Create an instance of a class using the specified ClassLoader

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_PROPERTIES_FILENAME

private static final java.lang.String DEFAULT_PROPERTIES_FILENAME

See Also:

Constant Field Values

SERVICES_PATH

private static final java.lang.String SERVICES_PATH

See Also:

Constant Field Values

DEBUG

private static final boolean DEBUG

Set to true for debugging

See Also:

Constant Field Values

fXalanProperties

private static java.util.Properties fXalanProperties

cache the contents of the xalan.properties file. Until an attempt has been made to read this file, this will be null; if the file does not exist or we encounter some other error during the read, this will be empty.

fLastModified

private static long fLastModified

Cache the time stamp of the xalan.properties file so that we know if it's been modified and can invalidate the cache when necessary.

Constructor Detail

ObjectFactory

ObjectFactory()

Method Detail

createObject

static java.lang.Object createObject(java.lang.String factoryId,
                                     java.lang.String fallbackClassName)
                              throws ObjectFactory.ConfigurationError

Finds the implementation Class object in the specified order. The specified order is the following:

1. query the system property using System.getProperty
2. read META-INF/services/factoryId file
3. use fallback classname

Parameters:

factoryId - Name of the factory to find, same as a property name

fallbackClassName - Implementation class name, if nothing else is found. Use null to mean no fallback.

Returns:

instance of factory, never null

Throws:

ObjectFactory.ConfigurationError

createObject

static java.lang.Object createObject(java.lang.String factoryId,
                                     java.lang.String propertiesFilename,
                                     java.lang.String fallbackClassName)
                              throws ObjectFactory.ConfigurationError

Finds the implementation Class object in the specified order. The specified order is the following:

1. query the system property using System.getProperty
2. read $java.home/lib/propertiesFilename file
3. read META-INF/services/factoryId file
4. use fallback classname

Parameters:

factoryId - Name of the factory to find, same as a property name

propertiesFilename - The filename in the $java.home/lib directory of the properties file. If none specified, ${java.home}/lib/xalan.properties will be used.

fallbackClassName - Implementation class name, if nothing else is found. Use null to mean no fallback.

Returns:

instance of factory, never null

Throws:

ObjectFactory.ConfigurationError

lookUpFactoryClass

static java.lang.Class lookUpFactoryClass(java.lang.String factoryId)
                                   throws ObjectFactory.ConfigurationError

Finds the implementation Class object in the specified order. The specified order is the following:

1. query the system property using System.getProperty
2. read $java.home/lib/propertiesFilename file
3. read META-INF/services/factoryId file
4. use fallback classname

Parameters:

factoryId - Name of the factory to find, same as a property name

propertiesFilename - The filename in the $java.home/lib directory of the properties file. If none specified, ${java.home}/lib/xalan.properties will be used.

fallbackClassName - Implementation class name, if nothing else is found. Use null to mean no fallback.

Returns:

Class object of factory, never null

Throws:

ObjectFactory.ConfigurationError

lookUpFactoryClass

static java.lang.Class lookUpFactoryClass(java.lang.String factoryId,
                                          java.lang.String propertiesFilename,
                                          java.lang.String fallbackClassName)
                                   throws ObjectFactory.ConfigurationError

Finds the implementation Class object in the specified order. The specified order is the following:

1. query the system property using System.getProperty
2. read $java.home/lib/propertiesFilename file
3. read META-INF/services/factoryId file
4. use fallback classname

Parameters:

factoryId - Name of the factory to find, same as a property name

propertiesFilename - The filename in the $java.home/lib directory of the properties file. If none specified, ${java.home}/lib/xalan.properties will be used.

fallbackClassName - Implementation class name, if nothing else is found. Use null to mean no fallback.

Returns:

Class object that provides factory service, never null

Throws:

ObjectFactory.ConfigurationError

lookUpFactoryClassName

static java.lang.String lookUpFactoryClassName(java.lang.String factoryId,
                                               java.lang.String propertiesFilename,
                                               java.lang.String fallbackClassName)

Finds the name of the required implementation class in the specified order. The specified order is the following:

1. query the system property using System.getProperty
2. read $java.home/lib/propertiesFilename file
3. read META-INF/services/factoryId file
4. use fallback classname

Parameters:

factoryId - Name of the factory to find, same as a property name

propertiesFilename - The filename in the $java.home/lib directory of the properties file. If none specified, ${java.home}/lib/xalan.properties will be used.

fallbackClassName - Implementation class name, if nothing else is found. Use null to mean no fallback.

Returns:

name of class that provides factory service, never null

Throws:

ObjectFactory.ConfigurationError

debugPrintln

private static void debugPrintln(java.lang.String msg)

Prints a message to standard error if debugging is enabled.

findClassLoader

static java.lang.ClassLoader findClassLoader()
                                      throws ObjectFactory.ConfigurationError

Figure out which ClassLoader to use. For JDK 1.2 and later use the context ClassLoader.

Throws:

ObjectFactory.ConfigurationError

newInstance

static java.lang.Object newInstance(java.lang.String className,
                                    java.lang.ClassLoader cl,
                                    boolean doFallback)
                             throws ObjectFactory.ConfigurationError

Create an instance of a class using the specified ClassLoader

Throws:

ObjectFactory.ConfigurationError

findProviderClass

static java.lang.Class findProviderClass(java.lang.String className,
                                         java.lang.ClassLoader cl,
                                         boolean doFallback)
                                  throws java.lang.ClassNotFoundException,
                                         ObjectFactory.ConfigurationError

Find a Class using the specified ClassLoader

Throws:

java.lang.ClassNotFoundException

ObjectFactory.ConfigurationError

findJarServiceProviderName

private static java.lang.String findJarServiceProviderName(java.lang.String factoryId)

Find the name of service provider using Jar Service Provider Mechanism

Returns:

instance of provider class if found or null