xUtils的HTTP整理

x xUtils是github上的一个Android开源工具项目，其中HttpUtils模块是处理网络连接部分，刚好最近想整理下Android网络编程知识，今天学习下xUtils中HttpUtils.   xUtils项目地址： https://github.com/wyouflf/xUtils  先看看分析的时序图，了解下基本的过程      1. Activity创建HttpUtils对象 HttpUtils http = new HttpUtils()； 复制代码 查看HttpUtils类的构造函数 public HttpUtils() {        this(HttpUtils.DEFAULT_CONN_TIMEOUT);        }        public HttpUtils(int connTimeout) {        HttpParams params = new BasicHttpParams();        ConnManagerParams.setTimeout(params, connTimeout);        HttpConnectionParams.setSoTimeout(params, connTimeout);        HttpConnectionParams.setConnectionTimeout(params, connTimeout);        ConnManagerParams.setMaxConnectionsPerRoute(params, new ConnPerRouteBean(10));        ConnManagerParams.setMaxTotalConnections(params, 10);        HttpConnectionParams.setTcpNoDelay(params, true);        HttpConnectionParams.setSocketBufferSize(params, 1024 * 8);        HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);        SchemeRegistry schemeRegistry = new SchemeRegistry();        schemeRegistry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));        schemeRegistry.register(new Scheme("https", DefaultSSLSocketFactory.getSocketFactory(), 443));        httpClient = new DefaultHttpClient(new ThreadSafeClientConnManager(params, schemeRegistry), params);        httpClient.setHttpRequestRetryHandler(new RetryHandler(DEFAULT_RETRY_TIMES));        httpClient.addRequestInterceptor(new HttpRequestInterceptor() {        @Override        public void process(org.apache.http.HttpRequest httpRequest, HttpContext httpContext) throws org.apache.http.HttpException, IOException {        if (!httpRequest.containsHeader(HEADER_ACCEPT_ENCODING)) {        httpRequest.addHeader(HEADER_ACCEPT_ENCODING, ENCODING_GZIP);        }        }        });        httpClient.addResponseInterceptor(new HttpResponseInterceptor() {        @Override        public void process(HttpResponse response, HttpContext httpContext) throws org.apache.http.HttpException, IOException {        final HttpEntity entity = response.getEntity();        if (entity == null) {        return;        }        final Header encoding = entity.getContentEncoding();        if (encoding != null) {        for (HeaderElement element : encoding.getElements()) {        if (element.getName().equalsIgnoreCase("gzip")) {        response.setEntity(new GZipDecompressingEntity(response.getEntity()));        return;        }        }        }        }        });        } 复制代码 这里主要是设置HttpParams参数，然后创建httpClient对象。 注意这个类ThreadSafeClientConnManager，它主要是为了使用线程安全的连接管理来创建HttpClient。 不过这里就有个疑问了，之前看资料了解到一般创建HttpClient都是用的 单例模式，说是一个httpClient就相当于是一个小型的浏览器，如果创建多个httpClient就很消耗资源了，我看了这个开源项目给的demo，是创建一个请求就创建一个HttpClient, 到时跟作者联系看看是什么回事。 2.发送请求 http.send(HttpRequest.HttpMethod.GET,        "http://www.baidu.com",        new RequestCallBack() {        @Override        public void onStart() {        resultText.setText("conn...");        }        @Override        public void onLoading(long total, long current, boolean isUploading) {        resultText.setText(current + "/" + total);        }        @Override        public void onSuccess(ResponseInfo responseInfo) {        resultText.setText("response:" + responseInfo.result);        }        @Override        public void onFailure(HttpException error, String msg) {        resultText.setText(msg);        }        }); 复制代码 调用send方法发生请求， HttpRequest.HttpMethod.GET指明请求的方式， "http://www.baidu.com"请求的地址， new RequestCallBack()请求的回调函数，这里面四个方法方便开发者处理请求的各个阶段的结果。 3. http.send() public  HttpHandler send(HttpRequest.HttpMethod method, String url, RequestCallBack callBack) {        return send(method, url, null, callBack); } public  HttpHandler send(HttpRequest.HttpMethod method, String url, RequestParams params, RequestCallBack callBack) {        if (url == null) throw new IllegalArgumentException("url may not be null");        HttpRequest request = new HttpRequest(method, url);        return sendRequest(request, params, callBack); } private  HttpHandler sendRequest(HttpRequest request, RequestParams params, RequestCallBack callBack) {        HttpHandler handler = new HttpHandler(httpClient, httpContext, responseTextCharset, callBack);        handler.setExpiry(currentRequestExpiry);        handler.setHttpRedirectHandler(httpRedirectHandler);        request.setRequestParams(params, handler);        handler.executeOnExecutor(executor, request);        return handler; } 复制代码 查看httpUtils的send函数，发现最后会调用sendRequest函数 在sendRequest里创建HttpHandler对象 4. HttpHandler HttpHandler extends CompatibleAsyncTask implements RequestCallBackHandler 复制代码 参看httpHandler发现它继承CompatibleAsyncTask 5.CompatibleAsyncTask   查看CompatibleAsyncTask ，发现它是A compatible AsyncTask for android2.2.你懂得  6.handler.executeOnExecutor(executor, request) 在第3步里创建完httpHandler后，调用handler.executeOnExecutor(executor, request)，而通过第4步了解到httpHandler继承CompatiableAsyncTask, 就先去看看doInBackground里做了什么事情。 7.doInBackground(Object... params) //先处理传递进来的params        this.publishProgress(UPDATE_START);        lastUpdateTime = SystemClock.uptimeMillis();        ResponseInfo responseInfo = sendRequest(request);        if (responseInfo != null) { this.publishProgress(UPDATE_SUCCESS, responseInfo); return null;        } 复制代码 先处理传递进来的params，调用publishProgress更新下当前的状态，然后调用sendRequest 8.sendRequest(HttpRequestBase request) private ResponseInfo sendRequest(HttpRequestBase request) throws HttpException {        HttpRequestRetryHandler retryHandler = client.getHttpRequestRetryHandler();        while (true) {        requestMethod = request.getMethod();        if (HttpUtils.sHttpCache.isEnabled(requestMethod)) {        String result = HttpUtils.sHttpCache.get(requestUrl);        if (result != null) {        return new ResponseInfo(null, (T) result, true);        }        }        ResponseInfo responseInfo = null;        if (!isCancelled()) {        HttpResponse response = client.execute(request, context);        responseInfo = handleResponse(response);        }        return responseInfo;        } catch (Exception e) {        exception = e;        retry = retryHandler.retryRequest(exception, ++retriedCount, context);        }        if (!retry) {        throw new HttpException(exception);        }        }        } 复制代码 这个方法仔细看看， 先获取下client.getHttpRequestRetryHandler()，获取retry的设置 requestMethod = request.getMethod(); if (HttpUtils.sHttpCache.isEnabled(requestMethod)) { String result = HttpUtils.sHttpCache.get(requestUrl); if (result != null) { return new ResponseInfo(null, (T) result, true); } } 复制代码 如果使用了缓存则通过requestUrl去httpCache去获取，获取到了则创建ResponseInfo对象 如果没有缓存 HttpResponse response = client.execute(request, context); responseInfo = handleResponse(response); 复制代码 调用httpClient执行http请求，获取到得结果交由handleResponse处理 如果之前的处理出现异常则 retry = retryHandler.retryRequest(exception, ++retriedCount, context); 复制代码 调用retry机制，直到有结果，或者超过retry的次数 9.handleResponse() 第8步的时候，如果client执行获取到结果则调用handleResponse(HttpResponse response)处理结果 public HttpUtils() {        this(HttpUtils.DEFAULT_CONN_TIMEOUT);        }        public HttpUtils(int connTimeout) {        HttpParams params = new BasicHttpParams();        ConnManagerParams.setTimeout(params, connTimeout);        HttpConnectionParams.setSoTimeout(params, connTimeout);        HttpConnectionParams.setConnectionTimeout(params, connTimeout);        ConnManagerParams.setMaxConnectionsPerRoute(params, new ConnPerRouteBean(10));        ConnManagerParams.setMaxTotalConnections(params, 10);        HttpConnectionParams.setTcpNoDelay(params, true);        HttpConnectionParams.setSocketBufferSize(params, 1024 * 8);        HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);        SchemeRegistry schemeRegistry = new SchemeRegistry();        schemeRegistry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));        schemeRegistry.register(new Scheme("https", DefaultSSLSocketFactory.getSocketFactory(), 443));        httpClient = new DefaultHttpClient(new ThreadSafeClientConnManager(params, schemeRegistry), params);        httpClient.setHttpRequestRetryHandler(new RetryHandler(DEFAULT_RETRY_TIMES));        httpClient.addRequestInterceptor(new HttpRequestInterceptor() {        @Override        public void process(org.apache.http.HttpRequest httpRequest, HttpContext httpContext) throws org.apache.http.HttpException, IOException {        if (!httpRequest.containsHeader(HEADER_ACCEPT_ENCODING)) {        httpRequest.addHeader(HEADER_ACCEPT_ENCODING, ENCODING_GZIP);        }        }        });        httpClient.addResponseInterceptor(new HttpResponseInterceptor() {        @Override        public void process(HttpResponse response, HttpContext httpContext) throws org.apache.http.HttpException, IOException {        final HttpEntity entity = response.getEntity();        if (entity == null) {        return;        }        final Header encoding = entity.getContentEncoding();        if (encoding != null) {        for (HeaderElement element : encoding.getElements()) {        if (element.getName().equalsIgnoreCase("gzip")) {        response.setEntity(new GZipDecompressingEntity(response.getEntity()));        return;        }        }        }        }        });        }0 复制代码 这个方法主要根据返回的statuscode处理，