encodes.java

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	}
	/**
	 * Sets a map of parameters (name=value) to a query string.
	 * If the name already exists in the query string, it will be removed first.
	 */
	public static final String setToQueryString(String str, Map params)
	throws UnsupportedEncodingException {
		return setToQueryString(new StringBuffer(str), params).toString();
	}
	/**
	 * Sets a map of parameters (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, Map params)
	throws UnsupportedEncodingException {
		if (params != null) {
			for (Iterator it = params.entrySet().iterator(); it.hasNext();) {
				final Map.Entry me = (Map.Entry)it.next();
				setToQueryString(sb, (String)me.getKey(), me.getValue());
			}
		}
		return sb;
	}
	/** Tests whether a parameter exists in the query string.
	 */
	public static final boolean containsQuery(String str, String name) {
		int j = str.indexOf(name);
		if (j <= 0)
			return false;

		char cc = str.charAt(j - 1);
		if (cc != '?' && cc != '&')
			return false;

		j += name.length();
		if (j >= str.length())
			return true;
		cc = str.charAt(j);
		return cc == '=' || cc == '&';
	}
	/** Remove all name/value pairs of the specified name from a string.
	 *
	 * <p>The query string might contain servlet path and other parts.
	 * This method starts the searching from the last '?'.
	 * If the query string doesn't contain '?', it is assumed to be a string
	 * without query's name/value pairs.
	 */
	public static final
	String removeFromQueryString(String str, String name)
	throws UnsupportedEncodingException {
		if (str == null)
			return null;

		int j = str.indexOf('?');
		if (j < 0)
			return str;

		final StringBuffer sb = new StringBuffer(str);
		removeFromQueryString(sb, name);
		return sb.length() == str.length() ? str: sb.toString();
	}
	/** Remove all name/value pairs of the specified name from a string.
	 */
	public static final StringBuffer
	removeFromQueryString(StringBuffer sb, String name)
	throws UnsupportedEncodingException {
		name = encodeURIComponent(name);
		int j = sb.indexOf("?");
		if (j < 0)
			return sb; //no '?'

		j = sb.indexOf(name, j + 1);
		if (j < 0)
			return sb; //no name

		final int len = name.length();
		do {
			//1. make sure left is & or ?
			int k = j + len;
			char cc = sb.charAt(j - 1);
			if (cc != '&' && cc != '?') {
				j = k;
				continue;
			}

			//2. make sure right is = or & or end-of-string
			if (k < sb.length()) {
				cc = sb.charAt(k);
				if (cc != '=' && cc != '&') {
					j = k;
					continue;
				}
			}

			//3. remove it until next & or end-of-string
			k = next(sb, '&', k);
			if (k < sb.length())
				sb.delete(j, k + 1); //also remove '&'
			else
				sb.delete(j - 1, k); //also preceding '?' or '&'
		} while ((j = sb.indexOf(name, j)) > 0);
		return sb;
	}

	/** Encodes a URL.
	 * It resolves "*" contained in URI, if any, to the proper Locale,
	 * and the browser code.
	 * Refer to {@link Servlets#locate(ServletContext, ServletRequest, String, Locator)}
	 * for details. 
	 *
	 * <p>In additions, if uri starts with "/", the context path, e.g.,
	 * /zkdemo, is prefixed.
	 * In other words, "/ab/cd" means it is relevant to the servlet
	 * context path (say, "/zkdemo").
	 *
	 * <p>If uri starts with "~abc/", it means it is relevant to a foreign
	 * Web context called /abc. And, it will be converted to "/abc/" first
	 * (without prefix request.getContextPath()).
	 *
	 * <p>Finally, the uri is encoded by HttpServletResponse.encodeURL.
	 *
	 * <p>This method invokes {@link #encodeURI} for any characters
	 * before '?'. However, it does NOT encode any character after '?'. Thus,
	 * you might hvae to invoke
	 * {@link #encodeURIComponent} or {@link #addToQueryString(StringBuffer,Map)}
	 * to encode the query parameters.
	 *
	 * @param request the request; never null
	 * @param response the response; never null
	 * @param uri it must be empty or starts with "/". It might contain
	 * "*" for current browser code and Locale.
	 * @param ctx the servlet context; used only if "*" is contained in uri
	 * @exception IndexOutOfBoundException if uri is empty
	 * @see #encodeURL(PageContext, String)
	 * @see org.zkoss.web.servlet.Servlets#locate
	 * @see org.zkoss.web.servlet.Servlets#generateURI
	 */
	public static final String encodeURL(ServletContext ctx,
	ServletRequest request, ServletResponse response, String uri)
	throws ServletException {
		try {
			return encodeURL0(ctx, request, response, uri);
		} catch (Exception ex) {
			log.realCause(ex);
			throw new ServletException("Unable to encode "+uri, ex);
		}
	}
	/** Encodes a URL.
	 *
	 * <p>It resolves "*" contained in URI, if any, to the proper Locale,
	 * and the browser code.
	 * Refer to {@link Servlets#locate(ServletContext, ServletRequest, String, Locator)}
	 * for details. 
	 *
	 * @see #encodeURL(ServletContext, ServletRequest, ServletResponse, String)
	 */
	public static final String encodeURL(PageContext ctx, String uri)
	throws JspException {
		try {
			return encodeURL0(ctx.getServletContext(),
				ctx.getRequest(), ctx.getResponse(), uri);
		} catch (Exception ex) {
			throw new JspException("Unable to encode "+uri, ex);
		}
	}

	private static final String encodeURL0(ServletContext ctx,
	ServletRequest request, ServletResponse response, String uri)
	throws Exception {
		if (uri == null || uri.length() == 0)
			return uri; //keep as it is

		boolean ctxpathSpecified = false;
		if (uri.charAt(0) != '/') { //NOT relative to context path
			if (Servlets.isUniversalURL(uri)) return uri; //nothing to do

			if (uri.charAt(0) == '~') { //foreign context
				final String ctxroot;
				if (uri.length() == 1) {
					ctxroot = uri = "/";
				} else if (uri.charAt(1) == '/') {
					ctxroot = "/";
					uri = uri.substring(1);
				} else {
					uri = '/' + uri.substring(1);
					final int j = uri.indexOf('/', 1);
					ctxroot = j >= 0 ? uri.substring(0, j): uri;
				}

				final ExtendedWebContext extctx =
					Servlets.getExtendedWebContext(ctx, ctxroot.substring(1));
				if (extctx != null) {
					final int j = uri.indexOf('/', 1);
					return extctx.encodeURL(request, response,
						j >= 0 ? uri.substring(j): "/");
				}

				final ServletContext newctx = ctx.getContext(ctxroot);
				if (newctx != null) {
					ctx = newctx;
				} else if (D.ON && log.debugable()) {
					log.debug("Context not found: "+ctxroot);
				}
				ctxpathSpecified = true;
			} else if (Https.isIncluded(request) || Https.isForwarded(request)) {
				//if reletive URI and being included/forwarded,
				//converts to absolute
				String pgpath = Https.getThisServletPath(request);
				if (pgpath != null) {
					int j = pgpath.lastIndexOf('/');
					if (j >= 0) {
						uri = pgpath.substring(0, j + 1) + uri;
					} else {
						log.warning("The current page doesn't contain '/':" + pgpath);
					}
				}
			}
		}

		//locate by locale and browser if necessary
		uri = Servlets.locate(ctx, request, uri, null);

		//prefix context path
		if (!ctxpathSpecified && uri.charAt(0) == '/'
		&& (request instanceof HttpServletRequest)) {
			//Work around with a bug when we wrap Pluto's RenderRequest (1.0.1)
			String ctxpath = ((HttpServletRequest)request).getContextPath();
			if (ctxpath.length() > 0 && ctxpath.charAt(0) != '/')
				ctxpath = '/' + ctxpath;
			uri = ctxpath + uri;
		}

		int j = uri.indexOf('?');
		if (j < 0) {
			uri = encodeURI(uri);
		} else {
			uri = encodeURI(uri.substring(0, j)) + uri.substring(j);
		}
		//encode
		if (response instanceof HttpServletResponse)
			uri = ((HttpServletResponse)response).encodeURL(uri);
		return uri;
	}
}