archive/working/apitools/org.eclipse.component/src/org/eclipse/component/location/Location.java

/**********************************************************************
 * Copyright (c) 2002, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 *
 * Contributors:
 *    IBM - Initial API and implementation
 **********************************************************************/

package org.eclipse.component.location;

import java.io.File;

/**
 * The <code>Location</code> class is a concrete implementation of 
 * the <code>ILocation</code> interface.  It provides a static
 * convienience method for creating new <code>Location</code> objects.
 * <p>
 * Note that all locations use '/' as their file separator.
 */
public abstract class Location implements ILocation {
	
	protected ILocation parent;
	protected String name;

	/**
	 * Creates a new <code>Location</code> with the given parent
	 * and the given name
	 * @param parent	The parent location, can be <code>null</code>
	 * @param fullName	The name of this location, cannot be <code>null</code>s
	 */
	public Location(ILocation parent, String fullName) {
		this.parent= parent;
		this.name= fullName.replace('\\', '/');
	}
	
	/*
	 * @see com.example.location.ILocation#accept(com.example.location.ILocationVisitor)
	 */
	public void accept(ILocationVisitor visitor) {
		if (visitor.accept(this)) {
			if (hasChildren()) {
				ILocationChildrenIterator i= childIterator();
				ILocation child= i.next();
				while(child != null) {
					child.accept(visitor);
					child= i.next();
				}
			}
		}
	}
	
	/*
	 * @see com.example.location.ILocation#getParent()
	 */
	public ILocation getParent() {
		return parent;
	}

	/*
	 * @see com.example.location.ILocation#getName()
	 */
	public String getName() {
		return name;
	}
	
	/**
	 * Creates a new location from a file.  Clients can create locations
	 * on directories or archive files (jar, zip, war, ear).
	 * 
	 * @param file	The file to wrap, not <code>null</code>
	 * @return ILocation	The resulting location, can be <code>null</code>
	 * 	if the file does not exist, is not a directory, or is not an archive.
	 */
	public static ILocation createLocation(File file) {
		if (!file.exists()) {
			return null;
		}
		
		if (file.isDirectory()) {
			return new FileLocation(file);
		}
		
		if (isArchive(file.getAbsolutePath())) {
			return new ZipLocation(file);
		}
		
		return null;
	}
	
	/**
	 * Answers <code>true</code> if the path ends in ".jar", 
	 * ".zip", ".ear", or ".war".
	 * <p>
	 * This code has been optimized to within an inch of its life. 
	 * @param path The path of the file
	 * @return boolean <code>true</code> if the path represents a
	 * 	jar, zip, ear, or war file.
	 */
	
	public static boolean isArchive(String path) {
		if (path == null)
			return false;
		if (path.length() < 5)
			return false;
		int index= path.length() - 1;
		char extChar= path.charAt(index--);
		switch (extChar) {
			case 'p':
			case 'P':
				if (path.endsWith(".zip")) {
					return true;
				}
				break;
			case 'r':
			case 'R':
				extChar= path.charAt(index--);
				switch (extChar) {
					case 'a':
					case 'A':
						extChar= path.charAt(index--);
						switch (extChar) {
							case 'j':
							case 'J':
								if (path.charAt(index) == '.') {
									return true;
								}
								break;
							case 'w':
							case 'W':
								if (path.charAt(index) == '.') {
									return true;
								}
								break;
							case 'e':
							case 'E':
								if (path.charAt(index) == '.') {
									return true;
								}
								break;
						}
				}
				break;
		}
		return false;
	}
	
	/**
	 * Answers the extension of the given path.  An extension
	 * is normally a three character addition to the end of a filename
	 * separated from the filename by the '.' character.
	 * 
	 * @param path a file path, not <code>null</code>
	 * @return String the extension of the path
	 */
	public static String getExtension(String path) {
		int index= path.lastIndexOf('.');
		if (index < 0)
			return "";
		return path.substring(index + 1).toLowerCase();
	}
	
	/*
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	public boolean equals(Object object) {
		if (object == null) {
			return false;
		}
		if (object == this) {
			return true;
		}
		if (object instanceof ILocation) {
			ILocation location= this;
			ILocation otherLocation= (ILocation) object;
			do {
				if (!location.getName().equals(otherLocation.getName())) {
					return false;
				}
				location= location.getParent();
				otherLocation= otherLocation.getParent();
			} while (location != null && otherLocation != null);

			if (location == null) {
				if (otherLocation == null) {
					return true;
				} else {
					return false;
				}
			} else {
				if (otherLocation == null) {
					return false;
				} else {
					return true;
				}
			}
		}
		return false;
	}
	
	/*
	 * @see java.lang.Object#hashCode()
	 */
	public int hashCode() {
		StringBuffer b= new StringBuffer();
		ILocation location= this;
		while(location != null) {
			b.insert(0, getName());
			location= location.getParent();
		}
		return b.toString().hashCode();
	}

}