Java tutorial
// Copyright (c) 2003-2013, LogMeIn, Inc. All rights reserved. // This is part of Xively4J library, it is under the BSD 3-Clause license. package com.andrestrequest.http; import java.io.UnsupportedEncodingException; import java.net.URI; import java.net.URISyntaxException; import java.util.Locale; import java.util.Map; import java.util.Map.Entry; import org.apache.http.Header; import org.apache.http.HttpException; 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.client.methods.HttpPut; import org.apache.http.client.methods.HttpRequestBase; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicHeader; import org.apache.http.util.EntityUtils; import org.json.JSONObject; import com.andrestrequest.AndRestConfig; import com.andrestrequest.AndRestConfig.AcceptedMediaType; import com.andrestrequest.http.apache.URIBuilder; import com.andrestrequest.util.GsonUtil; import com.andrestrequest.util.StringUtil; /** * Handler for building and making requests, uses {@link DefaultResponseHandler} * to process the response * @author s0pau */ @SuppressWarnings("deprecation") public class DefaultRequestHandler { public static boolean DEBUG = false; // private static final String HEADER_KEY_API = "X-ApiKey"; // private static final String HEADER_USER_AGENT = "User Agent"; // private static final String XIVELY_USER_AGENT = "Xively-Java-Lib/0.1.0-SNAPSHOT"; private DefaultHttpClient httpClient; private static DefaultRequestHandler instance; private DefaultResponseHandler responseHandler; public enum HttpMethod { DELETE, GET, POST, PUT, post; } private DefaultRequestHandler() { // singleton } public DefaultRequestHandler(DefaultResponseHandler responseHandler) { // singleton this.responseHandler = responseHandler; } public static DefaultRequestHandler getInstance() { if (instance == null) { instance = new DefaultRequestHandler(); } return instance; } public Response doRequest(HttpMethod method, String path) throws Exception { return doRequest(method, path, null, null, null); } public Response doRequest(HttpMethod method, String path, Object body) throws Exception { return doRequest(method, path, null, body, null); } public Response doRequest(HttpMethod method, String path, Map<String, String> headers) throws Exception { return doRequest(method, path, headers, null, null); } public Response doRequest(HttpMethod method, String path, Map<String, String> headers, Object body) throws Exception { return doRequest(method, path, headers, body, null); } public Response doRequest(HttpMethod method, String path, Map<String, String> headers, Map<String, Object> params) throws Exception { return doRequest(method, path, headers, null, params); } /** * * Make the request to Xively API and return the response string * @param <T extends ConnectedObject> * @param method * http request methods * @param path * restful app path * @param body * objects to be parsed as body for api call * @param params * key-value of params for api call * @param headers * @return response string * @throws HttpException */ public synchronized Response doRequest(HttpMethod method, String path, Map<String, String> headers, Object body, Map<String, Object> params) throws Exception { Response response = null; HttpRequestBase request = buildRequest(method, path, headers, body, params); if (DEBUG) { System.out.println(request); for (Header header : request.getAllHeaders()) { System.out.println(header); } if (body != null) { System.out.println(EntityUtils.toString(getEntity(body), AndRestConfig.getCharset())); } } if (responseHandler == null) { responseHandler = new DefaultResponseHandler(); } response = getClient().execute(request, responseHandler); return response; } private DefaultHttpClient getClient() { if (httpClient == null) { httpClient = HttpClientBuilder.getInstance().getHttpClient(); } return httpClient; } private HttpRequestBase buildRequest(HttpMethod method, String path, Map<String, String> headers, Object body, Map<String, Object> params) throws UnsupportedEncodingException { AcceptedMediaType mediaType = AndRestConfig.getResponseMediaType(); HttpRequestBase request = null; StringEntity entity = getEntity(body); switch (method) { case DELETE: request = new HttpDelete(); break; case GET: request = new HttpGet(); break; case POST: request = new HttpPost(); if (entity != null) { ((HttpPost) request).setEntity(entity); } break; case PUT: request = new HttpPut(); if (entity != null) { ((HttpPut) request).setEntity(entity); } break; default: return null; } try { if (!path.toLowerCase(Locale.ENGLISH).startsWith("http")) { URIBuilder builder = buildUri(method, path, params, mediaType); request.setURI(builder.build()); } else { request.setURI(new URI(path)); } } catch (URISyntaxException e) { throw new RequestInvalidException("Invalid URI requested.", e); } // request.addHeader("accept", mediaType.getMediaType()); // request.addHeader(HEADER_KEY_API, AppConfig.getInstance().getApiKey()); // request.addHeader(HEADER_USER_AGENT, XIVELY_USER_AGENT); /** * Header */ if (headers != null && !headers.isEmpty()) { int index = 0; Header[] header = new Header[headers.size()]; for (Entry<String, String> element : headers.entrySet()) { header[index++] = new BasicHeader(element.getKey(), element.getValue()); } request.setHeaders(header); } // if (params != null && !params.isEmpty()) { // HttpParams hparams = new SyncBasicHttpParams(); // for (Entry<String, Object> param : params.entrySet()) { // hparams.setParameter(param.getKey(), param.getValue()); // } // request.setParams(hparams); // } return request; } private URIBuilder buildUri(HttpMethod method, String path, Map<String, Object> params, AcceptedMediaType mediaType) throws UnsupportedEncodingException { URIBuilder uriBuilder = new URIBuilder(); // if (HttpMethod.GET == method) { // path = path.concat(".").concat(mediaType.name()); // } uriBuilder.setScheme("http").setHost(AndRestConfig.getBaseURI()) .setPath("/" + AndRestConfig.getVersion() + path); if (params != null && !params.isEmpty()) { for (Entry<String, Object> param : params.entrySet()) { uriBuilder.addParameter(param.getKey(), StringUtil.toString(param.getValue())); } } return uriBuilder; } private StringEntity getEntity(Object body) { AcceptedMediaType mediaType = AndRestConfig.getResponseMediaType(); String json = null;//ParserUtil.toJson(body); if (body instanceof JSONObject || body instanceof String) { // ? JSON json = body.toString(); } else if (body != null) { json = GsonUtil.toJson(body); } else { return null; } StringEntity entity = null; try { entity = new StringEntity(json, AndRestConfig.getCharset()); entity.setContentType(mediaType.getMediaType()); } catch (UnsupportedEncodingException e) { throw new RequestInvalidException("Unable to encode json string for making request.", e); } return entity; } }