escape.java

来自「用java开发的关于」· Java 代码 · 共 79 行

public class Escape
{
	public static String escape(String src)
	{
		int i;
		char j;
		StringBuffer tmp = new StringBuffer();
		tmp.ensureCapacity(src.length() * 6);
		for(i = 0; i < src.length(); i++)
		{
			j = src.charAt(i);
			if (Character.isDigit(j)
				|| Character.isLowerCase(j)
					|| Character.isUpperCase(j))
				tmp.append(j);
			else if (j < 256)
			{
				tmp.append("%");
				if (j < 16)
					tmp.append("0");
				tmp.append(Integer.toString(j, 16));
			}
			else
			{
				tmp.append("%u");
				tmp.append(Integer.toString(j, 16));
			}
		}
		return tmp.toString();
	}

	public static String unescape(String src)
	{
		StringBuffer tmp = new StringBuffer();
		tmp.ensureCapacity(src.length());
		int lastPos = 0, pos = 0;
		char ch;
		while(lastPos < src.length())
		{
			pos = src.indexOf("%", lastPos);
			if (pos == lastPos)
			{
				if (src.charAt(pos + 1) == 'u')
				{
					ch = (char)Integer
						.parseInt(src.substring(pos + 2, pos + 6), 16);
					tmp.append(ch);
					lastPos = pos + 6;
				}
				else
				{
					ch = (char)Integer
						.parseInt(src.substring(pos + 1, pos + 3), 16);
					tmp.append(ch);
					lastPos = pos + 3;
				}
			}
			else
			{
				if (pos == -1)
				{
					tmp.append(src.substring(lastPos));
					lastPos = src.length();
				}
				else
				{
					tmp.append(src.substring(lastPos, pos));
					lastPos = pos;
				}
			}
		}
		return tmp.toString();
	}
	public static void main(String[]args){
		System.out.println(3<<2);
	}
}