Java tutorial
/******************************************************************************* * Copyright 2012 University of Southern California * * 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. * * This code was developed by the Information Integration Group as part * of the Karma project at the Information Sciences Institute of the * University of Southern California. For more information, publications, * and related projects, please see: http://www.isi.edu/integration ******************************************************************************/ package edu.isi.karma.util; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.List; import java.util.Map; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.NameValuePair; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpDelete; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicNameValuePair; import org.json.JSONObject; import org.json.XML; public class HTTPUtil { private HTTPUtil() { } public enum HTTP_METHOD { GET, POST, PUT, DELETE, HEAD } public enum HTTP_HEADERS { Accept, } public static String executeHTTPPostRequest(String serviceURL, String contentType, String acceptContentType, HttpEntity entity) throws ClientProtocolException, IOException { HttpPost httpPost = new HttpPost(serviceURL); httpPost.setEntity(entity); return invokeHTTPRequest(httpPost, contentType, acceptContentType); } public static String executeHTTPPostRequest(String serviceURL, String contentType, String acceptContentType, Map<String, String> formParameters) throws ClientProtocolException, IOException { // Prepare the message body parameters List<NameValuePair> formParams = new ArrayList<>(); for (Map.Entry<String, String> stringStringEntry : formParameters.entrySet()) { formParams.add(new BasicNameValuePair(stringStringEntry.getKey(), stringStringEntry.getValue())); } return executeHTTPPostRequest(serviceURL, contentType, acceptContentType, new UrlEncodedFormEntity(formParams, "UTF-8")); } public static String executeHTTPPostRequest(String serviceURL, String contentType, String acceptContentType, String rawPostBodyData) throws ClientProtocolException, IOException { // Prepare the headers HttpPost httpPost = new HttpPost(serviceURL); httpPost.setEntity(new StringEntity(rawPostBodyData)); return invokeHTTPRequest(httpPost, contentType, acceptContentType); } private static String invokeHTTPRequest(HttpPost httpPost, String contentType, String acceptContentType) throws ClientProtocolException, IOException { HttpClient httpClient = new DefaultHttpClient(); if (acceptContentType != null && !acceptContentType.isEmpty()) { httpPost.setHeader(HTTP_HEADERS.Accept.name(), acceptContentType); } if (contentType != null && !contentType.isEmpty()) { httpPost.setHeader("Content-Type", contentType); } // Execute the request HttpResponse response = httpClient.execute(httpPost); // Parse the response and store it in a String HttpEntity entity = response.getEntity(); StringBuilder responseString = new StringBuilder(); if (entity != null) { BufferedReader buf = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8")); String line = buf.readLine(); while (line != null) { responseString.append(line); responseString.append('\n'); line = buf.readLine(); } } return responseString.toString(); } public static String executeHTTPGetRequest(String uri, String acceptContentType) throws ClientProtocolException, IOException { HttpClient httpClient = new DefaultHttpClient(); HttpGet request = new HttpGet(uri); if (acceptContentType != null && !acceptContentType.isEmpty()) { request.setHeader(HTTP_HEADERS.Accept.name(), acceptContentType); } HttpResponse response = httpClient.execute(request); // Parse the response and store it in a String HttpEntity entity = response.getEntity(); StringBuilder responseString = new StringBuilder(); if (entity != null) { BufferedReader buf = new BufferedReader(new InputStreamReader(entity.getContent())); String line = buf.readLine(); while (line != null) { responseString.append(line); responseString.append('\n'); line = buf.readLine(); } } return responseString.toString(); } public static Object executeAndParseHTTPGetService(String uri, boolean includeInputAttributes) throws ClientProtocolException, IOException { HttpClient httpClient = new DefaultHttpClient(); HttpGet request = new HttpGet(uri); request.setHeader(HTTP_HEADERS.Accept.name(), "application/json; text/xml"); HttpResponse response = httpClient.execute(request); // Parse the response and store it in a String HttpEntity entity = response.getEntity(); StringBuilder responseString = new StringBuilder(); if (entity != null) { BufferedReader buf = new BufferedReader(new InputStreamReader(entity.getContent())); String line = buf.readLine(); while (line != null) { responseString.append(line); responseString.append('\n'); line = buf.readLine(); } } Object output = null; if (entity.getContentType().toString().indexOf("xml") != -1) { output = XML.toJSONObject(responseString.toString()); } else if (entity.getContentType().toString().indexOf("json") != -1) { output = JSONUtil.createJson(responseString.toString()); } if (output != null && includeInputAttributes) { String[] queryParams = request.getURI().getQuery().split("&"); JSONObject nestedArr; if (output instanceof JSONObject) nestedArr = (JSONObject) output; else { nestedArr = new JSONObject(); nestedArr.put("output", output); } for (String queryParam : queryParams) { String[] param = queryParam.split("="); String name = param[0]; String value = param[1]; nestedArr.put(name, value); } JSONObject result = new JSONObject(); result.put("nestedArray", nestedArr); return result; } else { return output; } } public static String executeHTTPDeleteRequest(String uri) throws ClientProtocolException, IOException { HttpClient httpClient = new DefaultHttpClient(); HttpDelete request = new HttpDelete(uri); HttpResponse response = httpClient.execute(request); // Parse the response and store it in a String HttpEntity entity = response.getEntity(); StringBuilder responseString = new StringBuilder(); if (entity != null) { BufferedReader buf = new BufferedReader(new InputStreamReader(entity.getContent())); String line = buf.readLine(); while (line != null) { responseString.append(line); responseString.append('\n'); line = buf.readLine(); } } return responseString.toString(); } }