Java tutorial
/* * Copyright (c) 2012 Tyler Treat * * This file is part of Infinitum Framework. * * Infinitum Framework is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * Infinitum Framework is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with Infinitum Framework. If not, see <http://www.gnu.org/licenses/>. */ package com.clarionmedia.infinitum.http.rest.impl; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.UnsupportedEncodingException; import java.util.Date; import java.util.Locale; import java.util.Map; import java.util.Map.Entry; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.ProtocolException; import org.apache.http.StatusLine; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; 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.HttpUriRequest; import org.apache.http.entity.InputStreamEntity; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.impl.client.RequestWrapper; import org.apache.http.params.BasicHttpParams; import org.apache.http.params.HttpConnectionParams; import org.apache.http.params.HttpParams; import com.clarionmedia.infinitum.context.InfinitumContext; import com.clarionmedia.infinitum.context.RestfulContext; import com.clarionmedia.infinitum.exception.InfinitumRuntimeException; import com.clarionmedia.infinitum.http.impl.HashableHttpRequest; import com.clarionmedia.infinitum.http.rest.AuthenticationStrategy; import com.clarionmedia.infinitum.http.rest.RestfulClient; import com.clarionmedia.infinitum.internal.DateFormatter; import com.clarionmedia.infinitum.internal.caching.AbstractCache; import com.clarionmedia.infinitum.internal.caching.RestResponseCache; import com.clarionmedia.infinitum.logging.Logger; /** * <p> * Implementation of {@link RestfulClient} with caching support. * </p> * * @author Tyler Treat * @version 1.0 07/04/12 * @since 1.0 */ public class CachingEnabledRestfulClient implements RestfulClient { protected Logger mLogger; protected HttpParams mHttpParams; protected RestResponseCache mResponseCache; protected boolean mIsAuthenticated; protected AuthenticationStrategy mAuthStrategy; /** * Creates a new {@code CachingEnabledRestfulClient}. */ public CachingEnabledRestfulClient(InfinitumContext context) { mLogger = Logger.getInstance(context, getClass().getSimpleName()); mHttpParams = new BasicHttpParams(); mResponseCache = new RestResponseCache(); mResponseCache.enableDiskCache(context.getAndroidContext(), AbstractCache.DISK_CACHE_INTERNAL); RestfulContext restContext = context.getRestfulConfiguration(); if (restContext != null) { mIsAuthenticated = restContext.isRestAuthenticated(); mAuthStrategy = restContext.getAuthStrategy(); } } /** * Clears the response cache. */ public void clearCache() { mResponseCache.clear(); } @Override public RestResponse executeGet(String uri) { try { RequestWrapper request = new RequestWrapper(new HttpGet(uri)); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executeGet(String uri, Map<String, String> headers) { HttpGet httpGet = new HttpGet(uri); for (Entry<String, String> header : headers.entrySet()) { httpGet.addHeader(header.getKey(), header.getValue()); } try { RequestWrapper request = new RequestWrapper(httpGet); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePost(String uri, String messageBody, String contentType) { HttpPost httpPost = new HttpPost(uri); httpPost.addHeader("content-type", contentType); try { httpPost.setEntity(new StringEntity(messageBody, "UTF-8")); } catch (UnsupportedEncodingException e) { mLogger.error("Unable to send POST request (could not encode message body)", e); return null; } try { RequestWrapper request = new RequestWrapper(httpPost); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePost(String uri, String messageBody, String contentType, Map<String, String> headers) { HttpPost httpPost = new HttpPost(uri); for (Entry<String, String> header : headers.entrySet()) { httpPost.addHeader(header.getKey(), header.getValue()); } httpPost.addHeader("content-type", contentType); try { httpPost.setEntity(new StringEntity(messageBody, "UTF-8")); } catch (UnsupportedEncodingException e) { mLogger.error("Unable to send POST request (could not encode message body)", e); return null; } try { RequestWrapper request = new RequestWrapper(httpPost); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePost(String uri, HttpEntity httpEntity) { HttpPost httpPost = new HttpPost(uri); httpPost.addHeader("content-type", httpEntity.getContentType().getValue()); httpPost.setEntity(httpEntity); try { RequestWrapper request = new RequestWrapper(httpPost); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePost(String uri, HttpEntity httpEntity, Map<String, String> headers) { HttpPost httpPost = new HttpPost(uri); for (Entry<String, String> header : headers.entrySet()) { httpPost.addHeader(header.getKey(), header.getValue()); } httpPost.setEntity(httpEntity); try { RequestWrapper request = new RequestWrapper(httpPost); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePost(String uri, InputStream messageBody, int messageBodyLength, String contentType) { HttpPost httpPost = new HttpPost(uri); httpPost.addHeader("content-type", contentType); httpPost.setEntity(new InputStreamEntity(messageBody, messageBodyLength)); try { RequestWrapper request = new RequestWrapper(httpPost); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePost(String uri, InputStream messageBody, int messageBodyLength, String contentType, Map<String, String> headers) { HttpPost httpPost = new HttpPost(uri); for (Entry<String, String> header : headers.entrySet()) { httpPost.addHeader(header.getKey(), header.getValue()); } httpPost.addHeader("content-type", contentType); httpPost.setEntity(new InputStreamEntity(messageBody, messageBodyLength)); try { RequestWrapper request = new RequestWrapper(httpPost); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executeDelete(String uri) { try { RequestWrapper request = new RequestWrapper(new HttpDelete(uri)); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executeDelete(String uri, Map<String, String> headers) { HttpDelete httpDelete = new HttpDelete(uri); for (Entry<String, String> header : headers.entrySet()) { httpDelete.addHeader(header.getKey(), header.getValue()); } try { RequestWrapper request = new RequestWrapper(httpDelete); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePut(String uri, String messageBody, String contentType) { HttpPut httpPut = new HttpPut(uri); httpPut.addHeader("content-type", contentType); try { httpPut.setEntity(new StringEntity(messageBody, "UTF-8")); } catch (UnsupportedEncodingException e) { mLogger.error("Unable to send PUT request (could not encode message body)", e); return null; } try { RequestWrapper request = new RequestWrapper(httpPut); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePut(String uri, String messageBody, String contentType, Map<String, String> headers) { HttpPut httpPut = new HttpPut(uri); for (Entry<String, String> header : headers.entrySet()) { httpPut.addHeader(header.getKey(), header.getValue()); } httpPut.addHeader("content-type", contentType); try { httpPut.setEntity(new StringEntity(messageBody, "UTF-8")); } catch (UnsupportedEncodingException e) { mLogger.error("Unable to send PUT request (could not encode message body)", e); return null; } try { RequestWrapper request = new RequestWrapper(httpPut); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePut(String uri, HttpEntity httpEntity) { HttpPut httpPut = new HttpPut(uri); httpPut.addHeader("content-type", httpEntity.getContentType().getValue()); httpPut.setEntity(httpEntity); try { RequestWrapper request = new RequestWrapper(httpPut); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePut(String uri, HttpEntity httpEntity, Map<String, String> headers) { HttpPut httpPut = new HttpPut(uri); for (Entry<String, String> header : headers.entrySet()) { httpPut.addHeader(header.getKey(), header.getValue()); } httpPut.setEntity(httpEntity); try { RequestWrapper request = new RequestWrapper(httpPut); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePut(String uri, InputStream messageBody, int messageBodyLength, String contentType) { HttpPut httpPut = new HttpPut(uri); httpPut.addHeader("content-type", contentType); httpPut.setEntity(new InputStreamEntity(messageBody, messageBodyLength)); try { RequestWrapper request = new RequestWrapper(httpPut); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executePut(String uri, InputStream messageBody, int messageBodyLength, String contentType, Map<String, String> headers) { HttpPut httpPut = new HttpPut(uri); for (Entry<String, String> header : headers.entrySet()) { httpPut.addHeader(header.getKey(), header.getValue()); } httpPut.addHeader("content-type", contentType); httpPut.setEntity(new InputStreamEntity(messageBody, messageBodyLength)); try { RequestWrapper request = new RequestWrapper(httpPut); return executeRequest(new HashableHttpRequest(request)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public RestResponse executeRequest(HttpUriRequest request) { try { RequestWrapper wrapped = new RequestWrapper(request); return executeRequest(new HashableHttpRequest(wrapped)); } catch (ProtocolException e) { throw new InfinitumRuntimeException("Unable to execute request", e); } } @Override public void setConnectionTimeout(int timeout) { HttpConnectionParams.setConnectionTimeout(mHttpParams, timeout); } @Override public void setResponseTimeout(int timeout) { HttpConnectionParams.setSoTimeout(mHttpParams, timeout); } @Override public void setHttpParams(HttpParams httpParams) { mHttpParams = httpParams; } @Override public void setAuthStrategy(AuthenticationStrategy authStrategy) { mAuthStrategy = authStrategy; mIsAuthenticated = authStrategy != null; } private RestResponse executeRequest(HashableHttpRequest hashableHttpRequest) { if (mIsAuthenticated) mAuthStrategy.authenticate(hashableHttpRequest); if (mResponseCache.containsKey(hashableHttpRequest)) { RestResponse cachedResponse = mResponseCache.get(hashableHttpRequest); if (cachedResponse != null) return cachedResponse; } HttpUriRequest httpRequest = hashableHttpRequest.unwrap(); mLogger.debug("Sending " + httpRequest.getMethod() + " request to " + httpRequest.getURI() + " with " + httpRequest.getAllHeaders().length + " headers"); HttpClient httpClient = new DefaultHttpClient(mHttpParams); try { HttpResponse response = httpClient.execute(httpRequest); RestResponse restResponse = new RestResponse(response); StatusLine statusLine = response.getStatusLine(); restResponse.setStatusCode(statusLine.getStatusCode()); HttpEntity entity = response.getEntity(); if (entity == null) { restResponse.setResponseData(new byte[] {}); } else { ByteArrayOutputStream out = new ByteArrayOutputStream(); entity.writeTo(out); out.close(); restResponse.setResponseData(out.toByteArray()); } long expiration = getResponseExpiration(restResponse); if (expiration > 0) mResponseCache.put(hashableHttpRequest, restResponse, expiration); return restResponse; } catch (ClientProtocolException e) { mLogger.error("Unable to send " + httpRequest.getMethod() + " request", e); return null; } catch (IOException e) { mLogger.error("Unable to read web service response", e); return null; } } private long getResponseExpiration(RestResponse response) { long seconds = 0; try { for (Entry<String, String> header : response.getHeaders().entrySet()) { String name = header.getKey().trim(); if (name.equalsIgnoreCase("cache-control")) { String[] values = header.getValue().split(","); for (String cacheControl : values) { cacheControl = cacheControl.trim(); if (cacheControl.equalsIgnoreCase("no-cache") || cacheControl.equalsIgnoreCase("no-store") || cacheControl.equalsIgnoreCase("must-revalidate")) return 0; if (cacheControl.toLowerCase(Locale.getDefault()).startsWith("max-age")) { seconds = Long.parseLong(cacheControl.split("=")[1].trim()); } } } else if (name.equalsIgnoreCase("expires")) { Date expirationDate = DateFormatter.parseHttpExpiresStringAsDate(header.getValue().trim()); long difference = expirationDate.getTime() - System.currentTimeMillis(); if (difference > 0) seconds = difference; } else if (name.equalsIgnoreCase("pragma")) { if (header.getValue().trim().equalsIgnoreCase("no-cache")) return 0; } } } catch (Exception e) { mLogger.error("Unable to retrieve HTTP response expiration."); } return seconds; } }