edu.wisc.cs.stego.modules
Class ModuleLoader

java.lang.Object
  |
  +--java.lang.ClassLoader
        |
        +--edu.wisc.cs.stego.modules.ModuleLoader

public class ModuleLoader

extends java.lang.ClassLoader

This class is the engine which loads and instantiates plugin modules. It loads module classes on demand, and caches instances of the factory methods for future use. This interface hides the user from the uglyness of dealing with the java.lang.reflect classes needed to load and instantiate arbitrary class files.

See Also:

Encoder, Scanner

Method Summary

static CodeEditor	loadCodeEditor(java.lang.String classname, java.lang.String[] params) Instantiates the desired subclass of CodeEditor.
static Encoder	loadEncoder(java.lang.String classname, java.lang.String[] params) Instantiates the desired subclass of Encoder.
static Scanner	loadScanner(java.lang.String classname, java.lang.String[] params) Instantiates the desired subclass of Scanner.

Methods inherited from class java.lang.ClassLoader

defineClass, defineClass, defineClass, definePackage, findClass, findLibrary, findLoadedClass, findResource, findResources, findSystemClass, getPackage, getPackages, getParent, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, loadClass, resolveClass, setSigners

Methods inherited from class java.lang.Object

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

Method Detail

loadEncoder

public static Encoder loadEncoder(java.lang.String classname,
                                  java.lang.String[] params)
                           throws java.lang.Exception

Instantiates the desired subclass of Encoder. If necessary, this method loads and resolves the type. This method may throw MANY different exceptions, all of which are irrecoverable to most programs, assuming that the module being requested is necessary for the successful completion of the program. It may be useful for debugging purposes to print or examine the exception message, which may indicate a problem with the particular implementation of the requested module.

Assumptions about the parameters:

• The class must be locatable through the normal classpath searching mechanism provided by the Java Virtual Machine
• The class contained in the file is explicitly declared public.
• The class inherits directly or indirectly from Encoder.
• The buildEncoder method is overridden.

If any of these conditions are not met, this method will throw an appropriate exception.

Parameters:

classname - the fully qualified name of the Encoder subclass.

params - the parameters necessary to initialize the Encoder.

Returns:

an instance of the requested Encoder subclass type.

Throws:

many - exceptions.

See Also:

Encoder

loadCodeEditor

public static CodeEditor loadCodeEditor(java.lang.String classname,
                                        java.lang.String[] params)
                                 throws java.lang.Exception

Instantiates the desired subclass of CodeEditor. If necessary, this method loads and resolves the type. This method may throw MANY different exceptions, all of which are irrecoverable to most programs, assuming that the module being requested is necessary for the successful completion of the program. It may be useful for debugging purposes to print or examine the exception message, which may indicate a problem with the particular implementation of the requested module.

Assumptions about the parameters:

• The class must be locatable through the normal classpath searching mechanism provided by the Java Virtual Machine
• The class contained in the file is explicitly declared public.
• The class inherits directly or indirectly from CodeEditor.
• The buildCodeEditor method is overridden.

If any of these conditions are not met, this method will throw an appropriate exception.

Parameters:

classname - the fully qualified name of the CodeEditor subclass.

params - the parameters necessary to initialize the CodeEditor.

Returns:

an instance of the requested CodeEditor subclass type.

Throws:

many - exceptions.

See Also:

CodeEditor

loadScanner

public static Scanner loadScanner(java.lang.String classname,
                                  java.lang.String[] params)
                           throws java.lang.Exception

Instantiates the desired subclass of Scanner. If necessary, this method loads and resolves the type. This method may throw MANY different exceptions, all of which are irrecoverable to most programs, assuming that the module being requested is necessary for the successful completion of the program. It may be useful for debugging purposes to print or examine the exception message, which may indicate a problem with the particular implementation of the requested module.

Assumptions about the parameters:

• The class must be locatable through the normal classpath searching mechanism provided by the Java Virtual Machine.
• The class contained in the file is explicitly declared public.
• The class inherits directly or indirectly from Scanner.
• The buildScanner factory method is overridden.

If any of these conditions are not met, this method will throw an appropriate exception.

Parameters:

classname - the fully qualified name of the Scanner subclass.

params - the parameters necessary to initialize the Encoder.

Returns:

an instance of the requested Scanner subclass type.

Throws:

many - exceptions.

See Also:

Scanner