com.werken.forehead
Class Forehead

java.lang.Object
  com.werken.forehead.Forehead

public class Forehead

extends java.lang.Object

ClassLoader configurator and application launcher.

This is the main command-line entry-point into the forehead framework. Please see the forehead documentation for usage instructions.

Author:

bob mcwhirter

Field Summary

private java.util.Map	classLoaders ClassLoaders indexed by name.
private java.lang.Class	entryClass The entry-point class.
private ForeheadClassLoader	entryLoader The loader to use for entry-point lookup.
private java.lang.reflect.Method	entryMethod The entry-point method.
private static Forehead	INSTANCE Singleton.
private ForeheadClassLoader	rootLoader Root unnamed loader.

Constructor Summary

Forehead()
Construct.

Method Summary

void	config(java.io.BufferedReader in) Configure from an BufferedReader.
void	config(java.io.InputStream in) Configure from an InputStream.
void	config(java.io.Reader in) Configure from an Reader.
protected ForeheadClassLoader	createClassLoader(ForeheadClassLoader parent, java.lang.String name) Create a new ClassLoader given a parent and a name.
ForeheadClassLoader	getClassLoader(java.lang.String name) Retrieve a ClassLoader by name.
static Forehead	getInstance()
protected void	load(java.lang.String line, ForeheadClassLoader loader) Load a glob, file, or URL into the specified classloader.
protected void	loadFileOrUrl(java.lang.String line, ForeheadClassLoader loader) Load a file or URL into the specified classloader.
protected void	loadGlob(java.lang.String line, ForeheadClassLoader loader) Load a glob into the specified classloader.
static void	main(java.lang.String[] args) Main.
java.lang.String	resolveProperties(java.lang.String input, java.util.Properties props) Resolve imported properties.
void	run(java.lang.String[] args) Launch the wrapped application.
protected void	setupEntry(java.lang.String line) Setup the entry-point.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

private static final Forehead INSTANCE

Singleton.

classLoaders

private java.util.Map classLoaders

ClassLoaders indexed by name.

rootLoader

private ForeheadClassLoader rootLoader

Root unnamed loader.

entryLoader

private ForeheadClassLoader entryLoader

The loader to use for entry-point lookup.

entryClass

private java.lang.Class entryClass

The entry-point class.

entryMethod

private java.lang.reflect.Method entryMethod

The entry-point method.

Constructor Detail

Forehead

public Forehead()

Construct.

Method Detail

config

public void config(java.io.InputStream in)
            throws ForeheadException,
                   java.io.IOException,
                   java.lang.ClassNotFoundException

Configure from an InputStream.

Parameters:

in - InputStream carrying configuration information.

Throws:

ForeheadException - If there is an error during configuration.

java.io.IOException - If there is an error reading configuration information.

java.lang.ClassNotFoundException - If unable to locate entry-point class.

config

public void config(java.io.Reader in)
            throws ForeheadException,
                   java.io.IOException,
                   java.lang.ClassNotFoundException

Configure from an Reader.

Parameters:

in - Reader carrying configuration information.

Throws:

ForeheadException - If there is an error during configuration.

java.io.IOException - If there is an error reading configuration information.

java.lang.ClassNotFoundException - If unable to locate entry-point class.

config

public void config(java.io.BufferedReader in)
            throws ForeheadException,
                   java.io.IOException,
                   java.lang.ClassNotFoundException

Configure from an BufferedReader.

Parameters:

in - BufferedReader carrying configuration information.

Throws:

ForeheadException - If there is an error during configuration.

java.io.IOException - If there is an error reading configuration information.

java.lang.ClassNotFoundException - If unable to locate entry-point class.

setupEntry

protected void setupEntry(java.lang.String line)
                   throws MalformedEntryDescriptorException,
                          NoSuchClassLoaderException,
                          java.lang.ClassNotFoundException

Setup the entry-point.

Parameters:

line - The entry-point configuration line.

Throws:

MalformedEntryDescriptorException - If the entry-point descriptor is malformed.

NoSuchClassLoaderException - If the entry-point descriptor references an unknown ClassLoader.

java.lang.ClassNotFoundException - If unable to locate the entry-point class.

load

protected void load(java.lang.String line,
                    ForeheadClassLoader loader)
             throws java.net.MalformedURLException

Load a glob, file, or URL into the specified classloader.

Parameters:

line - The path configuration line.

loader - The loader to populate

Throws:

java.net.MalformedURLException - If the line does not represent a valid path element.

loadGlob

protected void loadGlob(java.lang.String line,
                        ForeheadClassLoader loader)
                 throws java.net.MalformedURLException

Load a glob into the specified classloader.

Parameters:

line - The path configuration line.

loader - The loader to populate

Throws:

java.net.MalformedURLException - If the line does not represent a valid path element.

loadFileOrUrl

protected void loadFileOrUrl(java.lang.String line,
                             ForeheadClassLoader loader)
                      throws java.net.MalformedURLException

Load a file or URL into the specified classloader.

Parameters:

line - The path configuration line.

loader - The loader to populate

Throws:

java.net.MalformedURLException - If the line does not represent a valid path element.

createClassLoader

protected ForeheadClassLoader createClassLoader(ForeheadClassLoader parent,
                                                java.lang.String name)

Create a new ClassLoader given a parent and a name.

Parameters:

parent - The parent of the ClassLoader to create.

name - The name of the ClassLoader to create.

Returns:

A newly configured ClassLoader.

getClassLoader

public ForeheadClassLoader getClassLoader(java.lang.String name)

Retrieve a ClassLoader by name.

Parameters:

name - The name of the ClassLoader to retrieve.

Returns:

The associated ClassLoader, or null if none.

resolveProperties

public java.lang.String resolveProperties(java.lang.String input,
                                          java.util.Properties props)

Resolve imported properties.

Parameters:

input - The string input to resolve properties.

props - Properties to resolve against.

Returns:

The string with properties resolved.

run

public void run(java.lang.String[] args)
         throws NoSuchEntryMethodException,
                java.lang.IllegalAccessException,
                java.lang.reflect.InvocationTargetException

Launch the wrapped application.

Parameters:

args - Command-line args to pass to wrapped application.

Throws:

NoSuchEntryMethodException - If unable to find the entry method on the class.

java.lang.IllegalAccessException - If an error occurs while attempting to invoke the entry-point method.

java.lang.reflect.InvocationTargetException - If an error occurs while attempting to invoke the entry-point method.

getInstance

public static Forehead getInstance()

main

public static void main(java.lang.String[] args)

Main.

Parameters:

args - Command-line arguments to pass to the wrapped application.