edu.iu.iv.common.util
Class JarScanner

java.lang.Object
  |
  +--edu.iu.iv.common.util.JarScanner

public class JarScanner

extends java.lang.Object

A utility class that can dynamically load classes from a set of paths, which may be jar files or folders which contain jars. The classes can then be scanned to enumerate the subtypes of a given class.

Author:

Josh Bonner

Constructor Summary

JarScanner()
Creates a JarScanner with no paths initially set.

JarScanner(java.lang.String[] jarPaths)
Creates a JarScanner and uses it to scan the given paths.

Method Summary

java.util.List	getInstantiableSubtypes(java.lang.Class supertype) Returns a list of the classes loaded by this scanner that are instantiable subtypes of the given supertype.
void	setScanPaths(java.lang.String[] jarPaths) Loads the classes from the jar files located at the given set of paths.

Methods inherited from class java.lang.Object

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

Constructor Detail

JarScanner

public JarScanner()

Creates a JarScanner with no paths initially set.

JarScanner

public JarScanner(java.lang.String[] jarPaths)
           throws java.io.IOException

Creates a JarScanner and uses it to scan the given paths.

Parameters:

jarPaths - the paths to scan

Throws:

java.io.IOException - if the scanner encounters an IO problem while processing one of the given paths

Method Detail

setScanPaths

public void setScanPaths(java.lang.String[] jarPaths)
                  throws java.io.IOException

Loads the classes from the jar files located at the given set of paths. The old class loader and set of loaded classes are discarded.

Parameters:

jarPaths - the paths to scan for jar files

Throws:

java.io.IOException - if an IO problem is encountered while processing one of the given paths

getInstantiableSubtypes

public java.util.List getInstantiableSubtypes(java.lang.Class supertype)

Returns a list of the classes loaded by this scanner that are instantiable subtypes of the given supertype.

Parameters:

supertype - the class whose subtypes are desired

Returns:

a list of subtype Classes