org.apache.commons.jxpath
Class JXPathContextFactory

java.lang.Object
  org.apache.commons.jxpath.JXPathContextFactory

Direct Known Subclasses:

JXPathContextFactoryReferenceImpl

public abstract class JXPathContextFactory

extends java.lang.Object

Defines a factory API that enables applications to obtain a JXPathContext instance. To acquire a JXPathContext, first call the static newInstance() method of JXPathContextFactory. This method returns a concrete JXPathContextFactory. Then call newContext() on that instance. You will rarely need to perform these steps explicitly: usually you can call one of the JXPathContex.newContext methods, which will perform these steps for you.

Version:

$Revision: 1.8 $ $Date: 2004/02/29 14:17:42 $

Author:

Dmitri Plotnikov

See Also:

JXPathContext.newContext(Object), JXPathContext.newContext(JXPathContext,Object)

Field Summary

private static boolean	debug Temp debug code - this will be removed after we test everything
private static java.lang.String	DEFAULT_FACTORY_CLASS The default factory class
static java.lang.String	FACTORY_NAME_PROPERTY The default property
private static java.lang.String	factoryImplName Avoid reading all the files when the findFactory method is called the second time ( cache the result of finding the default impl )

Constructor Summary

protected

JXPathContextFactory()

Method Summary

private static java.lang.String	findFactory(java.lang.String property, java.lang.String defaultFactory) Private implementation method - will find the implementation class in the specified order.
abstract JXPathContext	newContext(JXPathContext parentContext, java.lang.Object contextBean) Creates a new instance of a JXPathContext using the currently configured parameters.
static JXPathContextFactory	newInstance() Obtain a new instance of a JXPathContextFactory.

Methods inherited from class java.lang.Object

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

Field Detail

FACTORY_NAME_PROPERTY

public static final java.lang.String FACTORY_NAME_PROPERTY

The default property

See Also:

Constant Field Values

DEFAULT_FACTORY_CLASS

private static final java.lang.String DEFAULT_FACTORY_CLASS

The default factory class

See Also:

Constant Field Values

factoryImplName

private static java.lang.String factoryImplName

Avoid reading all the files when the findFactory method is called the second time ( cache the result of finding the default impl )

debug

private static boolean debug

Temp debug code - this will be removed after we test everything

Constructor Detail

JXPathContextFactory

protected JXPathContextFactory()

Method Detail

newInstance

public static JXPathContextFactory newInstance()

Obtain a new instance of a JXPathContextFactory. This static method creates a new factory instance. This method uses the following ordered lookup procedure to determine the JXPathContextFactory implementation class to load:

• Use the org.apache.commons.jxpath.JXPathContextFactory system property.
• Alternatively, use the JAVA_HOME (the parent directory where jdk is installed)/lib/jxpath.properties for a property file that contains the name of the implementation class keyed on org.apache.commons.jxpath.JXPathContextFactory.
• Use the Services API (as detailed in the JAR specification), if available, to determine the classname. The Services API will look for a classname in the file META- INF/services/org.apache.commons.jxpath. JXPathContextFactory in jars available to the runtime.
• Platform default JXPathContextFactory instance.

Once an application has obtained a reference to a JXPathContextFactory it can use the factory to obtain JXPathContext instances.

Throws:

JXPathFactoryConfigurationError - if the implementation is not available or cannot be instantiated.

newContext

public abstract JXPathContext newContext(JXPathContext parentContext,
                                         java.lang.Object contextBean)
                                  throws JXPathContextFactoryConfigurationError

Creates a new instance of a JXPathContext using the currently configured parameters.

Throws:

JXPathContextFactoryConfigurationError - if a JXPathContext cannot be created which satisfies the configuration requested

findFactory

private static java.lang.String findFactory(java.lang.String property,
                                            java.lang.String defaultFactory)

Private implementation method - will find the implementation class in the specified order.

Parameters:

property - Property name

defaultFactory - Default implementation, if nothing else is found

Returns:

class name of the JXPathContextFactory