Java tutorial
/* * Copyright (C) 2007 The Android Open Source Project * * 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. */ package fast.simple.download.http; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.zip.GZIPInputStream; import java.util.zip.GZIPOutputStream; import org.apache.http.Header; import org.apache.http.HttpEntity; import org.apache.http.HttpHost; import org.apache.http.HttpRequest; import org.apache.http.HttpRequestInterceptor; import org.apache.http.HttpResponse; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.ResponseHandler; import org.apache.http.client.methods.HttpUriRequest; import org.apache.http.client.protocol.ClientContext; import org.apache.http.conn.ClientConnectionManager; import org.apache.http.conn.scheme.PlainSocketFactory; import org.apache.http.conn.scheme.Scheme; import org.apache.http.conn.scheme.SchemeRegistry; import org.apache.http.entity.AbstractHttpEntity; import org.apache.http.entity.ByteArrayEntity; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager; import org.apache.http.params.BasicHttpParams; import org.apache.http.params.HttpConnectionParams; import org.apache.http.params.HttpParams; import org.apache.http.params.HttpProtocolParams; import org.apache.http.protocol.BasicHttpContext; import org.apache.http.protocol.BasicHttpProcessor; import org.apache.http.protocol.HttpContext; import android.content.ContentResolver; import android.content.Context; import android.net.SSLCertificateSocketFactory; import android.net.SSLSessionCache; import android.os.Looper; /** * Subclass of the Apache {@link DefaultHttpClient} that is configured with * reasonable default settings and registered schemes for Android, and also lets * the user add {@link HttpRequestInterceptor} classes. Don't create this * directly, use the {@link #newInstance} factory method. * * <p> * This client processes cookies but does not retain them by default. To retain * cookies, simply add a cookie store to the HttpContext: * </p> * * <pre> * context.setAttribute(ClientContext.COOKIE_STORE, cookieStore); * </pre> */ public final class DownloadHttpClient implements HttpClient { // Gzip of data shorter than this probably won't be worthwhile public static long DEFAULT_SYNC_MIN_GZIP_BYTES = 256; // Default connection and socket timeout of 60 seconds. Tweak to taste. private static final int SOCKET_OPERATION_TIMEOUT = 60 * 1000; private static final String TAG = "AndroidHttpClient"; /** Interceptor throws an exception if the executing thread is blocked */ private static final HttpRequestInterceptor sThreadCheckInterceptor = new HttpRequestInterceptor() { public void process(HttpRequest request, HttpContext context) { // Prevent the HttpRequest from being sent on the main thread if (Looper.myLooper() != null && Looper.myLooper() == Looper.getMainLooper()) { throw new RuntimeException("This thread forbids HTTP requests"); } } }; /** * Create a new HttpClient with reasonable defaults (which you can update). * * @param userAgent * to report in your HTTP requests * @param context * to use for caching SSL sessions (may be null for no caching) * @return AndroidHttpClient for you to use for all your requests. */ public static DownloadHttpClient newInstance(String userAgent, Context context) { HttpParams params = new BasicHttpParams(); // Turn off stale checking. Our connections break all the time anyway, // and it's not worth it to pay the penalty of checking every time. HttpConnectionParams.setStaleCheckingEnabled(params, false); HttpConnectionParams.setConnectionTimeout(params, SOCKET_OPERATION_TIMEOUT); HttpConnectionParams.setSoTimeout(params, SOCKET_OPERATION_TIMEOUT); HttpConnectionParams.setSocketBufferSize(params, 8192); // Don't handle redirects -- return them to the caller. Our code // often wants to re-POST after a redirect, which we must do ourselves. //HttpClientParams.setRedirecting(params, true); // Use a session cache for SSL sockets SSLSessionCache sessionCache = context == null ? null : new SSLSessionCache(context); // Set the specified user agent and register standard protocols. HttpProtocolParams.setUserAgent(params, userAgent); SchemeRegistry schemeRegistry = new SchemeRegistry(); schemeRegistry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80)); schemeRegistry.register(new Scheme("https", SSLCertificateSocketFactory.getHttpSocketFactory(SOCKET_OPERATION_TIMEOUT, sessionCache), 443)); ClientConnectionManager manager = new ThreadSafeClientConnManager(params, schemeRegistry); // We use a factory method to modify superclass initialization // parameters without the funny call-a-static-method dance. return new DownloadHttpClient(manager, params); } /** * Create a new HttpClient with reasonable defaults (which you can update). * * @param userAgent * to report in your HTTP requests. * @return AndroidHttpClient for you to use for all your requests. */ public static DownloadHttpClient newInstance(String userAgent) { return newInstance(userAgent, null /* session cache */); } private final HttpClient delegate; private RuntimeException mLeakedException = new IllegalStateException( "AndroidHttpClient created and never closed"); private DownloadHttpClient(ClientConnectionManager ccm, HttpParams params) { this.delegate = new DefaultHttpClient(ccm, params) { @Override protected BasicHttpProcessor createHttpProcessor() { // Add interceptor to prevent making requests from main thread. BasicHttpProcessor processor = super.createHttpProcessor(); processor.addRequestInterceptor(sThreadCheckInterceptor); //processor.addRequestInterceptor(new CurlLogger()); return processor; } @Override protected HttpContext createHttpContext() { // Same as DefaultHttpClient.createHttpContext() minus the // cookie store. HttpContext context = new BasicHttpContext(); context.setAttribute(ClientContext.AUTHSCHEME_REGISTRY, getAuthSchemes()); context.setAttribute(ClientContext.COOKIESPEC_REGISTRY, getCookieSpecs()); context.setAttribute(ClientContext.CREDS_PROVIDER, getCredentialsProvider()); return context; } }; } @Override protected void finalize() throws Throwable { if (mLeakedException != null) { mLeakedException = null; } super.finalize(); } /** * Modifies a request to indicate to the server that we would like a gzipped * response. (Uses the "Accept-Encoding" HTTP header.) * * @param request * the request to modify * @see #getUngzippedContent */ public static void modifyRequestToAcceptGzipResponse(HttpRequest request) { request.addHeader("Accept-Encoding", "gzip"); } /** * Gets the input stream from a response entity. If the entity is gzipped * then this will get a stream over the uncompressed data. * * @param entity * the entity whose content should be read * @return the input stream to read from * @throws IOException */ public static InputStream getUngzippedContent(HttpEntity entity) throws IOException { InputStream responseStream = entity.getContent(); if (responseStream == null) return responseStream; Header header = entity.getContentEncoding(); if (header == null) return responseStream; String contentEncoding = header.getValue(); if (contentEncoding == null) return responseStream; if (contentEncoding.contains("gzip")) responseStream = new GZIPInputStream(responseStream); return responseStream; } /** * Release resources associated with this client. You must call this, or * significant resources (sockets and memory) may be leaked. */ public void close() { if (mLeakedException != null) { getConnectionManager().shutdown(); mLeakedException = null; } } public HttpParams getParams() { return delegate.getParams(); } public ClientConnectionManager getConnectionManager() { return delegate.getConnectionManager(); } public HttpResponse execute(HttpUriRequest request) throws IOException { return delegate.execute(request); } public HttpResponse execute(HttpUriRequest request, HttpContext context) throws IOException { return delegate.execute(request, context); } public HttpResponse execute(HttpHost target, HttpRequest request) throws IOException { return delegate.execute(target, request); } public HttpResponse execute(HttpHost target, HttpRequest request, HttpContext context) throws IOException { return delegate.execute(target, request, context); } public <T> T execute(HttpUriRequest request, ResponseHandler<? extends T> responseHandler) throws IOException, ClientProtocolException { return delegate.execute(request, responseHandler); } public <T> T execute(HttpUriRequest request, ResponseHandler<? extends T> responseHandler, HttpContext context) throws IOException, ClientProtocolException { return delegate.execute(request, responseHandler, context); } public <T> T execute(HttpHost target, HttpRequest request, ResponseHandler<? extends T> responseHandler) throws IOException, ClientProtocolException { return delegate.execute(target, request, responseHandler); } public <T> T execute(HttpHost target, HttpRequest request, ResponseHandler<? extends T> responseHandler, HttpContext context) throws IOException, ClientProtocolException { return delegate.execute(target, request, responseHandler, context); } /** * Compress data to send to server. Creates a Http Entity holding the * gzipped data. The data will not be compressed if it is too short. * * @param data * The bytes to compress * @return Entity holding the data */ public static AbstractHttpEntity getCompressedEntity(byte data[], ContentResolver resolver) throws IOException { AbstractHttpEntity entity; if (data.length < getMinGzipSize(resolver)) { entity = new ByteArrayEntity(data); } else { ByteArrayOutputStream arr = zip(data); entity = new ByteArrayEntity(arr.toByteArray()); entity.setContentEncoding("gzip"); } return entity; } private static ByteArrayOutputStream zip(byte data[]) { ByteArrayOutputStream arr = new ByteArrayOutputStream(); OutputStream zipper = null; try { zipper = new GZIPOutputStream(arr); zipper.write(data); } catch (Exception e) { } finally { try { if (zipper != null) { zipper.close(); } } catch (Exception e) { } } return arr; } /** * Retrieves the minimum size for compressing data. Shorter data will not be * compressed. */ public static long getMinGzipSize(ContentResolver resolver) { return DEFAULT_SYNC_MIN_GZIP_BYTES; // For now, this is just a constant. } }