Java tutorial
/* * Copyright (C) 2011 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 com.baseproject.volley.toolbox; import java.io.IOException; import java.io.InputStream; import java.net.MalformedURLException; import java.net.SocketTimeoutException; import java.util.HashMap; import java.util.Map; import org.apache.http.Header; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.HttpStatus; import org.apache.http.StatusLine; import org.apache.http.conn.ConnectTimeoutException; import android.os.SystemClock; import android.text.TextUtils; import com.baseproject.network.HttpRequestManager; import com.baseproject.utils.Util; import com.baseproject.volley.Cache; import com.baseproject.volley.Network; import com.baseproject.volley.NetworkResponse; import com.baseproject.volley.Request; import com.baseproject.volley.RetryPolicy; import com.baseproject.volley.ServerError; import com.baseproject.volley.VolleyError; import com.baseproject.volley.VolleyLog; /** * A network performing Volley requests over an {@link HttpStack}. */ public class BasicNetwork implements Network { protected static final boolean DEBUG = VolleyLog.DEBUG; private static int SLOW_REQUEST_THRESHOLD_MS = 3000; private static int DEFAULT_POOL_SIZE = 4096 * 20; protected final HttpStack mHttpStack; protected final ByteArrayPool mPool; /** * @param httpStack * HTTP stack to be used */ public BasicNetwork(HttpStack httpStack) { // If a pool isn't passed in, then build a small default pool that will give us a lot of // benefit and not use too much memory. this(httpStack, new ByteArrayPool(DEFAULT_POOL_SIZE)); } /** * @param httpStack * HTTP stack to be used * @param pool * a buffer pool that improves GC performance in copy operations */ public BasicNetwork(HttpStack httpStack, ByteArrayPool pool) { mHttpStack = httpStack; mPool = pool; } @Override public NetworkResponse performRequest(Request<?> request) throws VolleyError { long requestStart = SystemClock.elapsedRealtime(); while (true) { HttpResponse httpResponse = null; byte[] responseContents = null; Map<String, String> responseHeaders = new HashMap<String, String>(); try { // Gather headers. Map<String, String> headers = new HashMap<String, String>(); addCacheHeaders(headers, request.getCacheEntry()); httpResponse = mHttpStack.performRequest(request, headers); StatusLine statusLine = httpResponse.getStatusLine(); int statusCode = statusLine.getStatusCode(); responseHeaders = convertHeaders(httpResponse.getAllHeaders()); // Handle cache validation. if (statusCode == HttpStatus.SC_NOT_MODIFIED) { return new NetworkResponse(HttpStatus.SC_NOT_MODIFIED, request.getCacheEntry() == null ? null : request.getCacheEntry().data, responseHeaders.get("Etag"), HttpHeaderParser.parseCharset(responseHeaders), true, request.getExpireTime()); } // Some responses such as 204s do not have content. We must check. if (httpResponse.getEntity() != null) { responseContents = entityToBytes(httpResponse.getEntity()); // TODO add to ensure download correct add by fenglei // long realLength = responseContents.length; // long requireLength = httpResponse.getEntity().getContentLength(); // if(realLength != requireLength && requireLength != -1) { // Log.i("Error", "realLength = " + realLength + ", requireLength = " + requireLength); // } if (responseContents != null && httpResponse.getEntity().getContentLength() > 0 && responseContents.length != httpResponse.getEntity().getContentLength()) { attemptRetryOnException("socket", request, new VolleyError(Util.buildHttpErrorMsg("failed", -1, "ContentLength Error"))); continue; } } else { // Add 0 byte response as a way of honestly representing a // no-content request. responseContents = new byte[0]; } // if the request is slow, log it. long requestLifetime = SystemClock.elapsedRealtime() - requestStart; logSlowRequests(requestLifetime, request, responseContents, statusLine); // if (statusCode < 200 || statusCode > 299) { // throw new IOException(); // } if (request.isUpdateCookie()) { Header[] cookies = httpResponse.getHeaders("Set-Cookie"); int count = cookies.length; int i = 0; StringBuilder cookieBuilder = new StringBuilder(); for (Header cookie : cookies) { String cookieStr = cookie.getValue(); i++; if (!TextUtils.isEmpty(cookieStr) && cookieStr.length() > 10) { int end = cookieStr.indexOf(" "); if (i == count) { cookieStr = cookieStr.subSequence(0, end - 1).toString(); } else { cookieStr = cookieStr.subSequence(0, end).toString(); } cookieBuilder.append(cookieStr).append(" "); } } if (cookieBuilder.length() > 0) { cookieBuilder.deleteCharAt(cookieBuilder.length() - 1); } request.setUpdateCookie(cookieBuilder.toString()); } return new NetworkResponse(statusCode, responseContents, responseHeaders.get("Etag"), HttpHeaderParser.parseCharset(responseHeaders), false, request.getExpireTime()); } catch (SocketTimeoutException e) { attemptRetryOnException("socket", request, new VolleyError( Util.buildHttpErrorMsg("failed", -1, HttpRequestManager.STATE_ERROR_TIMEOUT))); } catch (ConnectTimeoutException e) { attemptRetryOnException("connection", request, new VolleyError( Util.buildHttpErrorMsg("failed", -1, HttpRequestManager.STATE_ERROR_TIMEOUT))); } catch (MalformedURLException e) { throw new VolleyError(Util.buildHttpErrorMsg("failed", -1, HttpRequestManager.STATE_ERROR_MALFORMED_URL_EXCEPTION)); // throw new RuntimeException("Bad URL " + request.getUrl(), e); } catch (IOException e) { attemptRetryOnException("io", request, new VolleyError(e)); // int statusCode = 0; // NetworkResponse networkResponse = null; // if (httpResponse != null) { // statusCode = httpResponse.getStatusLine().getStatusCode(); // } else { // throw new NoConnectionError(e); // } // VolleyLog.e("Unexpected response code %d for %s", statusCode, request.getUrl()); // if (responseContents != null) { // networkResponse = new NetworkResponse(statusCode, responseContents, // responseHeaders, false); // if (statusCode == HttpStatus.SC_UNAUTHORIZED || // statusCode == HttpStatus.SC_FORBIDDEN) { // attemptRetryOnException("auth", // request, new AuthFailureError(networkResponse)); // } else { // // TODO: Only throw ServerError for 5xx status codes. // throw new ServerError(networkResponse); // } // } else { // throw new NetworkError(networkResponse); // } } } } /** * Logs requests that took over SLOW_REQUEST_THRESHOLD_MS to complete. */ private void logSlowRequests(long requestLifetime, Request<?> request, byte[] responseContents, StatusLine statusLine) { if (DEBUG || requestLifetime > SLOW_REQUEST_THRESHOLD_MS) { VolleyLog.d("HTTP response for request=<%s> [lifetime=%d], [size=%s], " + "[rc=%d], [retryCount=%s]", request, requestLifetime, responseContents != null ? responseContents.length : "null", statusLine.getStatusCode(), request.getRetryPolicy().getCurrentRetryCount()); } } /** * Attempts to prepare the request for a retry. If there are no more attempts remaining in the * request's retry policy, a timeout exception is thrown. * * @param request * The request to use. */ private static void attemptRetryOnException(String logPrefix, Request<?> request, VolleyError exception) throws VolleyError { RetryPolicy retryPolicy = request.getRetryPolicy(); int oldTimeout = request.getReadTimeoutMs(); try { retryPolicy.retry(exception); } catch (VolleyError e) { request.addMarker(String.format("%s-timeout-giveup [timeout=%s]", logPrefix, oldTimeout)); throw e; } request.addMarker(String.format("%s-retry [timeout=%s]", logPrefix, oldTimeout)); } private void addCacheHeaders(Map<String, String> headers, Cache.Entry entry) { // If there's no cache entry, we're done. if (entry == null) { return; } if (entry.etag != null) { headers.put("If-None-Match", entry.etag); } } protected void logError(String what, String url, long start) { long now = SystemClock.elapsedRealtime(); VolleyLog.v("HTTP ERROR(%s) %d ms to fetch %s", what, (now - start), url); } /** Reads the contents of HttpEntity into a byte[]. */ private byte[] entityToBytes(HttpEntity entity) throws IOException, ServerError { PoolingByteArrayOutputStream bytes = new PoolingByteArrayOutputStream(mPool, (int) entity.getContentLength()); byte[] buffer = null; try { InputStream in = entity.getContent(); if (in == null) { throw new ServerError(); } buffer = mPool.getBuf(1024 * 20); int count; while ((count = in.read(buffer)) != -1) { bytes.write(buffer, 0, count); } return bytes.toByteArray(); } finally { try { // Close the InputStream and release the resources by "consuming the content". entity.consumeContent(); } catch (IOException e) { // This can happen if there was an exception above that left the entity in // an invalid state. VolleyLog.v("Error occured when calling consumingContent"); } mPool.returnBuf(buffer); bytes.close(); } } /** * Converts Headers[] to Map<String, String>. */ private static Map<String, String> convertHeaders(Header[] headers) { Map<String, String> result = new HashMap<String, String>(); for (int i = 0; i < headers.length; i++) { result.put(headers[i].getName(), headers[i].getValue()); } return result; } }