Package net.sf.saxon.trans

Class DynamicLoader

java.lang.Object

net.sf.saxon.trans.DynamicLoader

All Implemented Interfaces:

IDynamicLoader

Direct Known Subclasses:

DynamicLoaderPE

public class DynamicLoader
extends Object
implements IDynamicLoader

Utility class used to perform dynamic loading of user-hook implementations

Field Summary

Fields

Modifier and Type	Field	Description
protected HashMap<String,Class<?>>	knownClasses

Constructor Summary

Constructors

Constructor	Description
DynamicLoader()

Method Summary

Modifier and Type	Method	Description
Class<?>	getClass(String className, Logger traceOut, ClassLoader classLoader)	Load a class using the class name provided.
ClassLoader	getClassLoader()	Get the ClassLoader supplied using the method setClassLoader(java.lang.ClassLoader).
Object	getInstance(String className, ClassLoader classLoader)	Instantiate a class using the class name provided.
Object	getInstance(String className, Logger traceOut, ClassLoader classLoader)	Instantiate a class using the class name provided, with the option of tracing Note that the method does not check that the object is of the right class.
InputStream	getResourceAsStream(String name)	Get a resource from a supplied URI using the classpath URI scheme.
protected void	registerKnownClasses()	Register classes that might be dynamically loaded even though they are contained within Saxon itself.
void	setClassLoader(ClassLoader loader)	Set a ClassLoader to be used when loading external classes.

Methods inherited from class java.lang.Object

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

Field Details

knownClasses

protected HashMap<String,Class<?>> knownClasses

Constructor Details

DynamicLoader

public DynamicLoader()

Method Details

registerKnownClasses

protected void registerKnownClasses()

Register classes that might be dynamically loaded even though they are contained within Saxon itself. This typically occurs for default implementations of classes that can be substituted or subclassed by the user.

setClassLoader

public void setClassLoader(ClassLoader loader)

Set a ClassLoader to be used when loading external classes. Examples of classes that are loaded include SAX parsers, localization modules for formatting numbers and dates, extension functions, external object models. In an environment such as Eclipse that uses its own ClassLoader, this ClassLoader should be nominated to ensure that any class loaded by Saxon is identical to a class of the same name loaded by the external environment.

Specified by:

setClassLoader in interface IDynamicLoader

Parameters:

loader - the ClassLoader to be used in this configuration

getClassLoader

public ClassLoader getClassLoader()

Get the ClassLoader supplied using the method setClassLoader(java.lang.ClassLoader). If none has been supplied, return null.

Returns:

the ClassLoader used in this configuration

getClass

public Class<?> getClass(String className,
 Logger traceOut,
 ClassLoader classLoader)
                  throws XPathException

Load a class using the class name provided. Note that the method does not check that the object is of the right class.

This method is intended for internal use only.

Specified by:

getClass in interface IDynamicLoader

Parameters:

className - A string containing the name of the class, for example "com.microstar.sax.LarkDriver"

traceOut - if diagnostic tracing is required, the destination for the output; otherwise null

classLoader - The ClassLoader to be used to load the class. If this is null, then the classLoader used will be the first one available of: the classLoader registered with the Configuration using setClassLoader(java.lang.ClassLoader); the context class loader for the current thread; or failing that, the class loader invoked implicitly by a call of Class.forName() (which is the ClassLoader that was used to load the Configuration object itself).

Returns:

an instance of the class named, or null if it is not loadable.

Throws:

XPathException - if the class cannot be loaded.

getInstance

public Object getInstance(String className,
 ClassLoader classLoader)
                   throws XPathException

Instantiate a class using the class name provided. Note that the method does not check that the object is of the right class.

This method is intended for internal use only.

Specified by:

getInstance in interface IDynamicLoader

Parameters:

className - A string containing the name of the class, for example "com.microstar.sax.LarkDriver"

classLoader - The ClassLoader to be used to load the class. If this is null, then the classLoader used will be the first one available of: the classLoader registered with the Configuration using setClassLoader(java.lang.ClassLoader); the context class loader for the current thread; or failing that, the class loader invoked implicitly by a call of Class.forName() (which is the ClassLoader that was used to load the Configuration object itself).

Returns:

an instance of the class named, or null if it is not loadable.

Throws:

XPathException - if the class cannot be loaded.

getInstance

public Object getInstance(String className,
 Logger traceOut,
 ClassLoader classLoader)
                   throws XPathException

Instantiate a class using the class name provided, with the option of tracing Note that the method does not check that the object is of the right class.

This method is intended for internal use only.

Specified by:

getInstance in interface IDynamicLoader

Parameters:

className - A string containing the name of the class, for example "com.microstar.sax.LarkDriver"

traceOut - if attempts to load classes are to be traced, then the destination for the trace output; otherwise null

classLoader - The ClassLoader to be used to load the class. If this is null, then the classLoader used will be the first one available of: the classLoader registered with the Configuration using setClassLoader(java.lang.ClassLoader); the context class loader for the current thread; or failing that, the class loader invoked implicitly by a call of Class.forName() (which is the ClassLoader that was used to load the Configuration object itself).

Returns:

an instance of the class named, or null if it is not loadable.

Throws:

XPathException - if the class cannot be loaded.

getResourceAsStream

public InputStream getResourceAsStream(String name)

Description copied from interface: IDynamicLoader

Get a resource from a supplied URI using the classpath URI scheme.

Specified by:

getResourceAsStream in interface IDynamicLoader

Parameters:

name - the path name from the URI

Returns:

the content of the relevant resource