Decoding and encoding URLs : URLDecoder « Network « Java Tutorial






/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */


import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.logging.Logger;


/**
 * Utility class for decoding and encoding URLs
 *
 */
public final class UrlUtils {
    

    private static final String[] RESERVED_CHARS = {"+"};
    private static final String[] ENCODED_CHARS = {"%2b"};
    
    private UrlUtils() {
        
    }

    /**
     * Decodes using URLDecoder - use when queries or form post values are decoded
     * @param value value to decode
     * @return
     */
    public static String urlDecode(String value) {
        try {
            value = URLDecoder.decode(value, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            System.out.println("UTF-8 encoding can not be used to decode " + value);          
        }
        return value;
    }
    
    /**
     * URL path segments may contain '+' symbols which should not be decoded into ' '
     * This method replaces '+' with %2B and delegates to URLDecoder
     * @param value value to decode
     * @return
     */
    public static String pathDecode(String value) {
        // TODO: we actually need to do a proper URI analysis here according to
        // http://tools.ietf.org/html/rfc3986
        for (int i = 0; i < RESERVED_CHARS.length; i++) {
            if (value.indexOf(RESERVED_CHARS[i]) != -1) {
                value = value.replace(RESERVED_CHARS[i], ENCODED_CHARS[i]);
            }
        }
        
        return urlDecode(value);
    }
    
}








19.4.URLDecoder
19.4.1.URL decoder
19.4.2.URLDecoder 2
19.4.3.URLEncoder: space
19.4.4.URLEncoder: asterisks
19.4.5.URLEncoder:
19.4.6.URLEncoder: plus sign
19.4.7.URLEncoder: slashes
19.4.8.URLEncoder: quotations
19.4.9.URLEncoder: colons(:)
19.4.10.URLEncoder: tildes(~)
19.4.11.URLEncoder: parentheses()
19.4.12.URLEncoder: dot
19.4.13.URLEncoder: equal sign
19.4.14.URLEncoder: ampersands
19.4.15.Converting x-www-form-urlencoded Data
19.4.16.Parse a x-www-form-urlencoded string
19.4.17.Encode a path as required by the URL specification
19.4.18.Decoding and encoding URLs
19.4.19.Provides a method to encode any string into a URL-safe form
19.4.20.Converting text to be used within a URL
19.4.21.URL encoding