localeutildecoderfallback.java

java 文件下载器。可自定义

// Decompiled by Jad v1.5.8e2. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://kpdus.tripod.com/jad.html
// Decompiler options: packimports(3) fieldsfirst ansi space 
// Source File Name:   LocaleUtilDecoderFallback.java

package org.gudy.azureus2.core3.internat;

import java.io.File;
import java.io.UnsupportedEncodingException;
import org.gudy.azureus2.core3.util.ByteFormatter;
import org.gudy.azureus2.core3.util.SHA1Hasher;

// Referenced classes of package org.gudy.azureus2.core3.internat:
//			LocaleUtilDecoder

public class LocaleUtilDecoderFallback
	implements LocaleUtilDecoder
{

	public static String NAME = "Fallback";
	private static volatile int max_ok_name_length = 64;
	private static volatile boolean max_ok_name_length_determined;
	private static final String VALID_CHARS = "abcdefghijklmnopqrstuvwxyz1234567890_-.";
	private int index;

	protected LocaleUtilDecoderFallback(int _index)
	{
		index = _index;
	}

	public String getName()
	{
		return NAME;
	}

	public int getIndex()
	{
		return index;
	}

	public String tryDecode(byte bytes[], boolean lax)
	{
		return decode(bytes);
	}

	public String decodeString(byte bytes[])
		throws UnsupportedEncodingException
	{
		return decode(bytes);
	}

	protected String decode(byte data[])
	{
		if (data == null)
			return null;
		StringBuffer res = new StringBuffer(data.length * 2);
		for (int i = 0; i < data.length; i++)
		{
			byte c = data[i];
			if ("abcdefghijklmnopqrstuvwxyz1234567890_-.".indexOf(Character.toLowerCase((char)c)) != -1)
			{
				res.append((char)c);
			} else
			{
				res.append("_");
				res.append(ByteFormatter.nicePrint(c));
			}
		}

		int len = res.length();
		if (len > max_ok_name_length)
			if (!max_ok_name_length_determined && fileLengthOK(len))
			{
				max_ok_name_length = len;
			} else
			{
				if (!max_ok_name_length_determined)
				{
					for (int i = max_ok_name_length + 16; i < len && fileLengthOK(i); i += 16)
						max_ok_name_length = i;

					max_ok_name_length_determined = true;
				}
				String extension = null;
				int pos = res.lastIndexOf(".");
				if (pos != -1)
				{
					extension = res.substring(pos);
					if (extension.length() == 1 || extension.length() > 4)
						extension = null;
				}
				byte hash[] = (new SHA1Hasher()).calculateHash(data);
				String hash_str = ByteFormatter.nicePrint(hash, true);
				res = new StringBuffer(res.substring(0, max_ok_name_length - hash_str.length() - (extension != null ? extension.length() : 0)));
				res.append(hash_str);
				if (extension != null)
					res.append(extension);
			}
		return res.toString();
	}

	protected boolean fileLengthOK(int len)
	{
		StringBuffer n;
		n = new StringBuffer(len);
		for (int i = 0; i < len; i++)
			n.append("A");

		File f = File.createTempFile(n.toString(), "");
		f.delete();
		return true;
		Throwable e;
		e;
		return false;
	}

}