org.objectweb.cjdbc.controller.connection
Class DriverClassLoader

java.lang.Object
  java.lang.ClassLoader
      org.objectweb.cjdbc.controller.connection.DriverClassLoader

public class DriverClassLoader

extends java.lang.ClassLoader

This class defines a DriverClassLoader used to load drivers with their own classloder to be able to handle different implementations of drivers sharing the same class name. For example if you want to connect to two backends of the same vendor, but running with different releases and requiring a driver compatible with the respective database release

Version:

1.0

Author:

Emmanuel Cecchet

Nested Class Summary

Nested classes inherited from class java.lang.ClassLoader

Field Summary

private java.util.Hashtable	htJarContents we cache the contents of the jar files, as we don't want to have to read the file for every single class we are going to need
private java.io.File	path path on filesystem where the driver is located

Fields inherited from class java.lang.ClassLoader

Constructor Summary

(package private)

DriverClassLoader(java.lang.ClassLoader parent, java.io.File pPath) Creates a new DriverClassLoader.java object

Method Summary

private java.lang.String	convertClassNameToResourceName(java.lang.String className) convert the class name into the rescource name.
protected java.lang.Class	findClass(java.lang.String className) finds the specified class
private byte[]	findClassInJarFile(java.io.File dir, java.lang.String className) Find the first jar file containing the className and load it
protected java.net.URL	findResource(java.lang.String name)
private void	loadJarFile(java.lang.String jarFileName) Load the contents of jar file in the cache

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, definePackage, findLibrary, findLoadedClass, findResources, findSystemClass, getPackage, getPackages, getParent, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, loadClass, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Field Detail

path

private java.io.File path

path on filesystem where the driver is located

htJarContents

private java.util.Hashtable htJarContents

we cache the contents of the jar files, as we don't want to have to read the file for every single class we are going to need

Constructor Detail

DriverClassLoader

DriverClassLoader(java.lang.ClassLoader parent,
                  java.io.File pPath)

Creates a new DriverClassLoader.java object

Parameters:

parent - classloader, null if no parent classloader should be used

pPath - path where the driver classfiles of jar files are located

Method Detail

findClass

protected java.lang.Class findClass(java.lang.String className)
                             throws java.lang.ClassNotFoundException

finds the specified class

Throws:

java.lang.ClassNotFoundException

See Also:

ClassLoader.findClass(java.lang.String)

findClassInJarFile

private byte[] findClassInJarFile(java.io.File dir,
                                  java.lang.String className)
                           throws java.io.IOException

Find the first jar file containing the className and load it

Parameters:

dir - directory where we are looking for jar files

className - name of the class we are looking for

Returns:

the class as byte[]

Throws:

java.io.IOException - if an error occurs

findResource

protected java.net.URL findResource(java.lang.String name)

See Also:

ClassLoader.findResource(java.lang.String)

convertClassNameToResourceName

private java.lang.String convertClassNameToResourceName(java.lang.String className)

convert the class name into the rescource name. This method is just replacing the '.' in the name with a '/' and adding the suffix '.class'

Parameters:

className -

Returns:

resource name

loadJarFile

private void loadJarFile(java.lang.String jarFileName)
                  throws java.io.IOException

Load the contents of jar file in the cache

Parameters:

jarFileName - name of the jar file we want to load

Throws:

java.io.IOException