strings.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:   Strings.java

package org.bouncycastle.util;

import java.io.ByteArrayOutputStream;
import java.util.Vector;

public final class Strings
{

	public Strings()
	{
	}

	public static String fromUTF8ByteArray(byte bytes[])
	{
		int i = 0;
		int length = 0;
		while (i < bytes.length) 
		{
			length++;
			if ((bytes[i] & 0xf0) == 240)
			{
				length++;
				i += 4;
			} else
			if ((bytes[i] & 0xe0) == 224)
				i += 3;
			else
			if ((bytes[i] & 0xc0) == 192)
				i += 2;
			else
				i++;
		}
		char cs[] = new char[length];
		i = 0;
		length = 0;
		char ch;
		for (; i < bytes.length; cs[length++] = ch)
		{
			if ((bytes[i] & 0xf0) == 240)
			{
				int codePoint = (bytes[i] & 3) << 18 | (bytes[i + 1] & 0x3f) << 12 | (bytes[i + 2] & 0x3f) << 6 | bytes[i + 3] & 0x3f;
				int U = codePoint - 0x10000;
				char W1 = (char)(0xd800 | U >> 10);
				char W2 = (char)(0xdc00 | U & 0x3ff);
				cs[length++] = W1;
				ch = W2;
				i += 4;
				continue;
			}
			if ((bytes[i] & 0xe0) == 224)
			{
				ch = (char)((bytes[i] & 0xf) << 12 | (bytes[i + 1] & 0x3f) << 6 | bytes[i + 2] & 0x3f);
				i += 3;
				continue;
			}
			if ((bytes[i] & 0xd0) == 208)
			{
				ch = (char)((bytes[i] & 0x1f) << 6 | bytes[i + 1] & 0x3f);
				i += 2;
				continue;
			}
			if ((bytes[i] & 0xc0) == 192)
			{
				ch = (char)((bytes[i] & 0x1f) << 6 | bytes[i + 1] & 0x3f);
				i += 2;
			} else
			{
				ch = (char)(bytes[i] & 0xff);
				i++;
			}
		}

		return new String(cs);
	}

	public static byte[] toUTF8ByteArray(String string)
	{
		ByteArrayOutputStream bOut = new ByteArrayOutputStream();
		char c[] = string.toCharArray();
		for (int i = 0; i < c.length; i++)
		{
			char ch = c[i];
			if (ch < '\200')
			{
				bOut.write(ch);
				continue;
			}
			if (ch < '\u0800')
			{
				bOut.write(0xc0 | ch >> 6);
				bOut.write(0x80 | ch & 0x3f);
				continue;
			}
			if (ch >= '\uD800' && ch <= '\uDFFF')
			{
				if (i + 1 >= c.length)
					throw new IllegalStateException("invalid UTF-16 codepoint");
				char W1 = ch;
				ch = c[++i];
				char W2 = ch;
				if (W1 > '\uDBFF')
					throw new IllegalStateException("invalid UTF-16 codepoint");
				int codePoint = ((W1 & 0x3ff) << 10 | W2 & 0x3ff) + 0x10000;
				bOut.write(0xf0 | codePoint >> 18);
				bOut.write(0x80 | codePoint >> 12 & 0x3f);
				bOut.write(0x80 | codePoint >> 6 & 0x3f);
				bOut.write(0x80 | codePoint & 0x3f);
			} else
			{
				bOut.write(0xe0 | ch >> 12);
				bOut.write(0x80 | ch >> 6 & 0x3f);
				bOut.write(0x80 | ch & 0x3f);
			}
		}

		return bOut.toByteArray();
	}

	public static String toUpperCase(String string)
	{
		boolean changed = false;
		char chars[] = string.toCharArray();
		for (int i = 0; i != chars.length; i++)
		{
			char ch = chars[i];
			if ('a' <= ch && 'z' >= ch)
			{
				changed = true;
				chars[i] = (char)((ch - 97) + 65);
			}
		}

		if (changed)
			return new String(chars);
		else
			return string;
	}

	public static String toLowerCase(String string)
	{
		boolean changed = false;
		char chars[] = string.toCharArray();
		for (int i = 0; i != chars.length; i++)
		{
			char ch = chars[i];
			if ('A' <= ch && 'Z' >= ch)
			{
				changed = true;
				chars[i] = (char)((ch - 65) + 97);
			}
		}

		if (changed)
			return new String(chars);
		else
			return string;
	}

	public static byte[] toByteArray(String string)
	{
		byte bytes[] = new byte[string.length()];
		for (int i = 0; i != bytes.length; i++)
		{
			char ch = string.charAt(i);
			bytes[i] = (byte)ch;
		}

		return bytes;
	}

	public static String[] split(String input, char delimiter)
	{
		Vector v = new Vector();
		for (boolean moreTokens = true; moreTokens;)
		{
			int tokenLocation = input.indexOf(delimiter);
			if (tokenLocation > 0)
			{
				String subString = input.substring(0, tokenLocation);
				v.addElement(subString);
				input = input.substring(tokenLocation + 1);
			} else
			{
				moreTokens = false;
				v.addElement(input);
			}
		}

		String res[] = new String[v.size()];
		for (int i = 0; i != res.length; i++)
			res[i] = (String)v.elementAt(i);

		return res;
	}
}