responseutils.java

电子地图服务器,搭建自己的地图服务

/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org.  All rights reserved.
 * This code is licensed under the GPL 2.0 license, availible at the root
 * application directory.
 */
package org.geoserver.ows.util;

import java.io.IOException;
import java.io.Writer;


/**
 * Utility class performing operations related to http respones.
 *
 * @author Justin Deoliveira, The Open Planning Project, [e-mail]
 *
 */
public class ResponseUtils {
    /**
     * Parses the passed string, and encodes the special characters (used in
     * xml for special purposes) with the appropriate codes. e.g. '<' is
     * changed to '&lt;'
     *
     * @param inData The string to encode into xml.
     *
     * @return the encoded string. Returns null, if null is passed as argument
     *
     */
    public static String encodeXML(String inData) {
        //return null, if null is passed as argument
        if (inData == null) {
            return null;
        }

        //if no special characters, just return
        //(for optimization. Though may be an overhead, but for most of the
        //strings, this will save time)
        if ((inData.indexOf('&') == -1) && (inData.indexOf('<') == -1)
                && (inData.indexOf('>') == -1) && (inData.indexOf('\'') == -1)
                && (inData.indexOf('\"') == -1)) {
            return inData;
        }

        //get the length of input String
        int length = inData.length();

        //create a StringBuffer of double the size (size is just for guidance
        //so as to reduce increase-capacity operations. The actual size of
        //the resulting string may be even greater than we specified, but is
        //extremely rare)
        StringBuffer buffer = new StringBuffer(2 * length);

        char charToCompare;

        //iterate over the input String
        for (int i = 0; i < length; i++) {
            charToCompare = inData.charAt(i);

            //if the ith character is special character, replace by code
            if (charToCompare == '&') {
                buffer.append("&amp;");
            } else if (charToCompare == '<') {
                buffer.append("&lt;");
            } else if (charToCompare == '>') {
                buffer.append("&gt;");
            } else if (charToCompare == '\"') {
                buffer.append("&quot;");
            } else if (charToCompare == '\'') {
                buffer.append("&apos;");
            } else {
                buffer.append(charToCompare);
            }
        }

        //return the encoded string
        return buffer.toString();
    }

    /**
     * Writes <CODE>string</CODE> into writer, escaping &, ', ", <, and >
     * with the XML excape strings.
     */
    public static void writeEscapedString(Writer writer, String string)
        throws IOException {
        for (int i = 0; i < string.length(); i++) {
            char c = string.charAt(i);

            if (c == '<') {
                writer.write("&lt;");
            } else if (c == '>') {
                writer.write("&gt;");
            } else if (c == '&') {
                writer.write("&amp;");
            } else if (c == '\'') {
                writer.write("&apos;");
            } else if (c == '"') {
                writer.write("&quot;");
            } else {
                writer.write(c);
            }
        }
    }

    /**
     * Appends a query string to a url.
     * <p>
     * This method checks <code>url</code> to see if the appended query string requires a '?' or
     * '&' to be prepended.
     * </p>
     *
     * @param url The base url.
     * @param queryString The query string to be appended, should not contain the '?' character.
     *
     * @return A full url with the query string appended.
     * 
     * TODO: remove this and replace with Requetss.appendQueryString
     */
    public static String appendQueryString(String url, String queryString) {
        if (url.endsWith("?") || url.endsWith("&")) {
            return url + queryString;
        }

        if (url.indexOf('?') != -1) {
            return url + "&" + queryString;
        }

        return url + "?" + queryString;
    }

    /**
     * Strips the query string off a request url.
     *
     * @param url The url.
     *
     * @return The original minus the query string.
     */
    public static String stripQueryString(String url) {
        int index = url.indexOf('?');

        if (index == -1) {
            return url;
        }

        return url.substring(0, index);
    }

    /**
     * Appends a path tpo a url.
     * <p>
     * This method checks <code>url</code> to see if the appended path requires a '/' to be
     * prepended.
     * </p>
     * @param url The base url.
     * @param path The path to be appended to the url.
     *
     * @return The full url with the path appended.
     * TODO: remove this and replace with Requetss.appendContextPath
     */
    public static String appendPath(String url, String path) {
        if (path.startsWith("/")) {
            path = path.substring(1);
        }

        return url.endsWith("/") ? (url + path) : (url + "/" + path);
    }
}