filelocator.java.svn-base

一个timesheet程序,用来统计开发人员的度量衡web在线程序.用于软件行业

package com.nsi.util;

import java.io.File;
import java.net.URL;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.nsi.constants.AppConstants;

/**
 * @author Chris Ye, created on Oct 26, 2008
 *
 * FileLocator
 */
public final class FileLocator
{
	private final static Log log = LogFactory.getLog(FileLocator.class);
	/**
	 * private constructor of FileLocator
	 */
	private FileLocator()
	{
	}
	private static class FileLocatorHolder
	{
		static FileLocator locator = new FileLocator();
	}
	public static FileLocator getInstance()
	{
		return FileLocatorHolder.locator;
	}
	public String searchforFile( String filename )
	{
		log.debug("searchforFile() -- filename["+filename+"]");
		ClassLoader cl = FileLocator.class.getClassLoader();
		URL url = cl.getResource( filename );
		if( url != null ) 
		{
			log.debug("searchforFile() -- url["+url+"]");
			return url.getFile();
		}
		try 
		{
			String file = null;
			url = FileLocator.class.getProtectionDomain().getCodeSource().getLocation();
			log.debug("searchforFile() -- protection domain url["+url+"]");
			file = url.getFile();
			File dir = new File( file );
			if ( ( dir.isFile() ) || ( !dir.exists() ) ) dir = dir.getParentFile();
			String sourceFile = filename;
			File f = null;
			for ( ;( dir != null ); dir = dir.getParentFile() ) 
			{
				f = new File( dir, sourceFile );
				if( f.exists() ) break;
				else 
				{
					f = new File( dir, sourceFile );
					if( f.exists() ) break;
				}
			}
			if( f.exists() ) 
			{
				return f.getAbsolutePath();
			} 
			else 
			{
				return null;
			}
		}
		catch( Throwable t ) 
		{
			return null;
		}
	}
	public String retrieveParentpath( String filename )
	{
		log.debug("retrieveParentpath() -- filename["+filename+"]");
		String path = AppConstants.EMPTY_STRING;
		try 
		{
			File dir = new File( filename );
			if ( dir.isFile()) path = dir.getParent();
		}
		catch( Throwable t ) 
		{
		}
		return path;
	}
}