Java tutorial
/** * Copyright (c) 2012, Jilles van Gurp * * 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. */ package com.jillesvangurp.urlbuilder; import java.io.UnsupportedEncodingException; import java.net.MalformedURLException; import java.net.URL; import java.net.URLEncoder; import java.util.LinkedHashMap; import java.util.Map; import java.util.Map.Entry; import org.apache.commons.lang.StringUtils; /** * Simple builder class to construct urls out of a base url, one or more post fixes, and query parameters. * * The builder class enables you to not worry about things like trailing slashes, url encoding, etc. * */ public class UrlBuilder { private final StringBuilder url; // preserve order in which parameters are added private final Map<String, String> params = new LinkedHashMap<String, String>(); private UrlBuilder(String baseUrl) { url = new StringBuilder(baseUrl); } public static UrlBuilder url(String baseUrl) { return new UrlBuilder(baseUrl); } public static UrlBuilder url(String host, int port) { return new UrlBuilder("http://" + host + ":" + port); } public String build() { StringBuilder result = new StringBuilder(url); if (params.size() > 0) { result.append('?'); for (Entry<String, String> entry : params.entrySet()) { String value = entry.getValue(); result.append(entry.getKey() + '=' + value); result.append('&'); } result.deleteCharAt(result.length() - 1); // remove trailing & } return result.toString(); } public URL buildUrl() { try { return new URL(build()); } catch (MalformedURLException e) { throw new IllegalArgumentException(e); } } public UrlBuilder append(String... postFix) { return append(true, postFix); } public UrlBuilder append(boolean encode, String... postFix) { for (String part : postFix) { if (StringUtils.isNotBlank(part)) { if (url.charAt(url.length() - 1) != '/' && !part.startsWith("/")) { url.append('/'); } if (encode) { try { url.append(URLEncoder.encode(part, "UTF-8")); } catch (UnsupportedEncodingException e) { throw new IllegalStateException(e); } } else { url.append(part); } } } return this; } public UrlBuilder queryParam(String name, Boolean value) { if (value != null) { return queryParam(name, value.toString()); } else { return null; } } public UrlBuilder queryParam(String name, Number value) { if (value != null) { return queryParam(name, value.toString()); } else { return null; } } public UrlBuilder queryParam(String name, String value) { return queryParam(name, value, true); } public UrlBuilder queryParam(String name, String value, boolean escape) { if (StringUtils.isNotEmpty(value)) { if (escape) { try { value = URLEncoder.encode(value, "UTF-8"); } catch (UnsupportedEncodingException e) { throw new IllegalStateException(e); } } params.put(name, value); } return this; } }