Java URL Query Build createQueryString(Map params)

Description

Create a query String using the given parameters.

License

Open Source License

Parameter

Parameter	Description
params	a parameter

Return

Query String

Declaration

public static String createQueryString(Map<String, String> params) 

Method Source Code

//package com.java2s;
/*/*w  ww .  j a  va2 s  .  c  o m*/
 * The MIT License
 *
 * Copyright (c) 2009, 2010 Stefan Saasen
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

import java.util.Iterator;
import java.util.Map;

import java.util.Map.Entry;

public class Main {
    /**
     * Create a query String using the given parameters.
     * <pre>
     * Map<String,String> map = new LinkedHashMap<String,String>();
     * map.put("k1", "value1");
     * map.put("k2", "value2");
     * 
     * String s = StringUtils.createQueryString(params);
     * 
     * // => "?k1=value1&k2=value2"
     * </pre>
     * @param params
     * @return Query String
     */
    public static String createQueryString(Map<String, String> params) {
        if (null == params || params.isEmpty()) {
            return "";
        }
        StringBuilder sb = new StringBuilder();
        if (!params.isEmpty()) {
            sb.append("?");
            try {

                for (Iterator<Entry<String, String>> iterator = params.entrySet().iterator(); iterator.hasNext();) {
                    final Entry<String, String> entry = iterator.next();
                    sb.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
                    sb.append("=");
                    sb.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
                    if (iterator.hasNext()) {
                        sb.append("&");
                    }
                }
            } catch (UnsupportedEncodingException ue) {
                // ignore - UTF-8 is mandatory
            }
        }
        return sb.toString();
    }
}

Related

1. createQueryString(Map options)
2. createQueryString(Map params)
3. createQueryStringForParameters(Map parameters)
4. createQueryStringFromMap(Map m, String ampersand, boolean encode)
5. getQuery(Map params, String encode)