Java tutorial
//package com.java2s; /* * Copyright 2012 Google Inc. * * Licensed 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.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import java.util.Iterator; import java.util.Map; import java.util.Map.Entry; public class Main { /** * Issue a POST request to the server. * * @param endpoint * POST address. * @param params * request parameters. * * @throws java.io.IOException * propagated from POST. */ public static String post(String endpoint, Map<String, String> params) throws IOException { URL url; try { url = new URL(endpoint); } catch (MalformedURLException e) { throw new IllegalArgumentException("invalid url: " + endpoint); } StringBuilder bodyBuilder = new StringBuilder(); Iterator<Entry<String, String>> iterator = params.entrySet().iterator(); // constructs the POST body using the parameters while (iterator.hasNext()) { Entry<String, String> param = iterator.next(); bodyBuilder.append(param.getKey()).append('=').append(param.getValue()); if (iterator.hasNext()) { bodyBuilder.append('&'); } } String body = bodyBuilder.toString(); byte[] bytes = body.getBytes(); HttpURLConnection conn = null; try { conn = (HttpURLConnection) url.openConnection(); conn.setDoOutput(true); conn.setUseCaches(false); conn.setFixedLengthStreamingMode(bytes.length); conn.setRequestMethod("POST"); conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8"); // post the request OutputStream out = conn.getOutputStream(); out.write(bytes); out.close(); // handle the response int status = conn.getResponseCode(); if (status != 200) { throw new IOException("Post failed with error code " + status); } // Get Response InputStream is = conn.getInputStream(); BufferedReader rd = new BufferedReader(new InputStreamReader(is)); String line; StringBuffer response = new StringBuffer(); while ((line = rd.readLine()) != null) { response.append(line); response.append('\n'); } rd.close(); return response.toString(); } finally { if (conn != null) { conn.disconnect(); } } } }