encodes.java

非常接近C/S操作方式的Java Ajax框架－ZK 用ZK框架使你的B/S应用程序更漂亮更易操作。 官网：www.zkoss.org

/* Encodes.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Fri Jun 21 14:13:50  2002, Created by tomyeh
}}IS_NOTE

Copyright (C) 2002 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
	This program is distributed under GPL Version 2.0 in the hope that
	it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.web.servlet.http;

import java.util.Arrays;
import java.util.Map;
import java.util.Set;
import java.util.HashSet;
import java.util.Locale;
import java.util.Iterator;
import java.io.UnsupportedEncodingException;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletContext;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.JspException;

import org.zkoss.lang.D;
import org.zkoss.lang.Objects;
import org.zkoss.util.logging.Log;

import org.zkoss.web.Attributes;
import org.zkoss.web.servlet.Servlets;
import org.zkoss.web.servlet.Charsets;
import org.zkoss.web.util.resource.ExtendedWebContext;

/**
 * Encoding utilities for servlets.
 *
 * @author tomyeh
 * @see Https
 */
public class Encodes {
	private static final Log log = Log.lookup(Encodes.class);

	/** Encodes a string to HTTP URI compliant by use of
	 * {@link Charsets#getURICharset}.
	 *
	 * <p>Besides two-byte characters, it also encodes any character found
	 * in unsafes.
	 *
	 * @param unsafes the set of characters that must be encoded; never null.
	 * It must be sorted.
	 */
	private static final String encodeURI0(String s, char[] unsafes)
	throws UnsupportedEncodingException {
		if (s == null)
			return null;

		final String charset = Charsets.getURICharset();
		final byte[] in = s.getBytes(charset);
		final byte[] out = new byte[in.length * 3];//at most: %xx
		int j = 0, k = 0;
		for (; j < in.length; ++j) {
			//Though it is ok to use '+' for ' ', Jetty has problem to
			//handle space between chinese characters.
			final char cc = (char)(((int)in[j]) & 0xff);
			if (cc >= 0x80 || cc <= ' '
			|| Arrays.binarySearch(unsafes, cc) >= 0) {
				out[k++] = (byte)'%';
				String cvt = Integer.toHexString(cc);
				if (cvt.length() == 1) {
					out[k++] = (byte)'0';
					out[k++] = (byte)cvt.charAt(0);
				} else {
					out[k++] = (byte)cvt.charAt(0);
					out[k++] = (byte)cvt.charAt(1);
				}
			} else {
				out[k++] = in[j];
			}
		}
		return j == k ? s: new String(out, 0, k, charset);
	}
	/** unsafe character when that are used in url's localtion. */
	private static final char[] URI_UNSAFE;
	/** unsafe character when that are used in url's query. */
	private static final char[] URI_COMP_UNSAFE;
	static {
		URI_UNSAFE = "`%^{}[]\\\"<>|".toCharArray();
		Arrays.sort(URI_UNSAFE);

		URI_COMP_UNSAFE = "`%^{}[]\\\"<>|$&,/:;=?".toCharArray();
		Arrays.sort(URI_COMP_UNSAFE);
	}

	/** Does the HTTP encoding for the URI location.
	 * For example, '%' is translated to '%25'.
	 *
	 * <p>Since {@link #encodeURL(ServletContext, ServletRequest, ServletResponse, String)}
	 * will invoke this method automatically, you rarely need this method.
	 *
	 * @param s the string to encode; null is OK
	 * @return the encoded string or null if s is null
	 * @see #encodeURIComponent
	 */
	public static final String encodeURI(String s)
	throws UnsupportedEncodingException {
		return encodeURI0(s, URI_UNSAFE);
	}
	/** Does the HTTP encoding for a URI query parameter.
	 * For example, '/' is translated to '%2F'.
	 * Both name and value must be encoded seperately. Example,
	 * <code>encodeURIComponent(name) + '=' + encodeURIComponent(value)</code>.
	 *
	 * <p>Since {@link #encodeURL(ServletContext, ServletRequest, ServletResponse, String)}
	 * will <i>not</i> invoke this method automatically, you'd better
	 * to encode each query parameter by this method or
	 * {@link #addToQueryString(StringBuffer,Map)}.
	 *
	 * @param s the string to encode; null is OK
	 * @return the encoded string or null if s is null
	 * @see #addToQueryString(StringBuffer,String,Object)
	 * @see #encodeURI
	 */
	public static final String encodeURIComponent(String s)
	throws UnsupportedEncodingException {
		return encodeURI0(s, URI_COMP_UNSAFE);
	}
	/**
	/** Appends a map of parameters (name=value) to a query string.
	 * It returns the query string preceding with '?' if any parameter exists,
	 * or an empty string if no parameter at all. Thus, you could do
	 *
	 * <p><code>request.getRequestDispatcher(<br>
	 * addToQueryStirng(new StringBuffer(uri), params).toString());</code>
	 *
	 * <p>Since RequestDispatcher.include and forward do not allow wrapping
	 * the request and response -- see spec and the implementation of both
	 * Jetty and Catalina, we have to use this method to pass the parameters.
	 *
	 * @param params a map of parameters; format: (String, Object) or
	 * (String, Object[]); null is OK
	 */
	public static final StringBuffer
	addToQueryString(StringBuffer sb, Map params)
	throws UnsupportedEncodingException {
		if (params != null) {
			for (Iterator it = params.entrySet().iterator(); it.hasNext();) {
				final Map.Entry me = (Map.Entry)it.next();
				addToQueryString(sb, (String)me.getKey(), me.getValue());
			}
		}
		return sb;
	}
	/** Appends a parameter (name=value) to a query string.
	 * This method automatically detects whether other query is already
	 * appended. If so, &amp; is used instead of ?.
	 *
	 * <p>The query string might contain servlet path and other parts.
	 * This method starts the searching from the first '?'.
	 * If the query string doesn't contain '?', it is assumed to be a string
	 * without query's name/value pairs.
	 *
	 * @param value the value. If it is null, only name is appened.
	 * If it is an array of objects, multipe pairs of name=value[j] will
	 * be appended.
	 */
	public static final StringBuffer
	addToQueryString(StringBuffer sb, String name, Object value)
	throws UnsupportedEncodingException {
		if (value instanceof Object[]) {
			final Object[] vals = (Object[])value;
			if (vals.length == 0) {
				value = null; //only append name
			} else {
				for (int j = 0; j < vals.length; ++j)
					addToQueryString(sb, name, vals[j]);
				return sb; //done
			}
		}

		sb.append(next(sb, '?', 0) >= sb.length() ? '?': '&');
		sb.append(encodeURIComponent(name)).append('=');
			//NOTE: jetty with jboss3.0.6 ignore parameters without '=',
			//so we always append '=' even value is null
		if (value != null)
			sb.append(encodeURIComponent(Objects.toString(value)));

		return sb;
	}

	/** Returns the first occurrence starting from j, or sb.length().
	 */
	private static final int next(StringBuffer sb, char cc, int j) {
		for (final int len = sb.length(); j < len; ++j)
			if (sb.charAt(j) == cc)
				break;
		return j;
	}

	/**
	 * Sets the parameter (name=value) to a query string.
	 * If the name already exists in the query string, it will be removed first.
	 * If your name has appeared in the string, it will replace
	 * your new value to the query string.
	 * Otherwise, it will append the name/value to the new string. 
	 *
	 * <p>The query string might contain servlet path and other parts.
	 * This method starts the searching from the first '?'.
	 * If the query string doesn't contain '?', it is assumed to be a string
	 * without query's name/value pairs.
	 *
	 * @param str The query string like xxx?xxx=xxx&xxx=xxx or null.
	 * @param name The get parameter name.
	 * @param value The value associated with the get parameter name. 
	 * @return The new or result query string with your name/value.
	 */
	public static final
	String setToQueryString(String str, String name, Object value)
	throws UnsupportedEncodingException {
		final StringBuffer sb = new StringBuffer();
		if (str != null)
			sb.append(str);
		return setToQueryString(sb, name, value).toString();
	}
	/**
	 * Sets the parameter (name=value) to a query string.
	 * If the name already exists in the query string, it will be
	 * removed first.
	 */
	public static final StringBuffer
	setToQueryString(StringBuffer sb, String name, Object value)
	throws UnsupportedEncodingException {
		removeFromQueryString(sb, name);
		return addToQueryString(sb, name, value);