package jd.cli.loader;

import java.io.DataInputStream;
import java.io.File;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

import jd.core.loader.LoaderException;


public class JarLoader extends BaseLoader
{
	private ZipFile zipFile;
	
	public JarLoader(File file) throws LoaderException
	{	
		super(file);
		
		if (! (file.exists() && file.isFile()))
		{
			throw new LoaderException("'" + codebase + "' is not a directory");			
		}
		
		try 
		{
			this.zipFile = new ZipFile(codebase);
		}
		catch (IOException e) 
		{
			throw new LoaderException("Error reading from '" + codebase + "'");
		}
	}
	
	public DataInputStream load(String internalPath)
		throws LoaderException
	{
		ZipEntry zipEntry = this.zipFile.getEntry(internalPath);
		
		if (zipEntry == null)
		{
			throw new LoaderException("Can not read '" + internalPath + "'");
		}
		
		try 
		{
			return new DataInputStream(this.zipFile.getInputStream(zipEntry));
		} 
		catch (IOException e) 
		{
			throw new LoaderException("Error reading '" + internalPath + "'");
		}
	}

	public boolean canLoad(String internalPath) 
	{
		return this.zipFile.getEntry(internalPath) != null;
	}
}
