关于Httpclient的总结（二）
(8)针对在HTTPClient采用压缩格式的文件的传输，必须采用拦截器进行特殊的处理public class ClientGZipContentCompression { public final static void main(String[] args) throws Exception { DefaultHttpClient httpclient = new DefaultHttpClient(); //设置相关的压缩文件标识，在请求头的信息中 httpclient.addRequestInterceptor(new HttpRequestInterceptor() { public void process( final HttpRequest request, final HttpContext context) throws HttpException, IOException { if (!request.containsHeader("Accept-Encoding")) { request.addHeader("Accept-Encoding", "gzip"); } } }); //设置相应相应的拦截器，用于处理接收到的拦截的压缩信息 httpclient.addResponseInterceptor(new HttpResponseInterceptor() { public void process( final HttpResponse response, final HttpContext context) throws HttpException, IOException { HttpEntity entity = response.getEntity(); Header ceheader = entity.getContentEncoding(); if (ceheader != null) { HeaderElement[] codecs = ceheader.getElements(); for (int i = 0; i < codecs.length; i++) { if (codecs[i].getName().equalsIgnoreCase("gzip")) { response.setEntity( new GzipDecompressingEntity(response.getEntity())); return; } } } } }); HttpGet httpget = new HttpGet("http://www.apache.org/"); // Execute HTTP request System.out.println("executing request " + httpget.getURI()); HttpResponse response = httpclient.execute(httpget); System.out.println("----------------------------------------"); System.out.println(response.getStatusLine()); System.out.println(response.getLastHeader("Content-Encoding")); System.out.println(response.getLastHeader("Content-Length")); System.out.println("----------------------------------------"); HttpEntity entity = response.getEntity(); if (entity != null) { String content = EntityUtils.toString(entity); System.out.println(content); System.out.println("----------------------------------------"); System.out.println("Uncompressed size: "+content.length()); } // When HttpClient instance is no longer needed, // shut down the connection manager to ensure // immediate deallocation of all system resources httpclient.getConnectionManager().shutdown(); } //压缩文件处理的实体包装类 static class GzipDecompressingEntity extends HttpEntityWrapper { public GzipDecompressingEntity(final HttpEntity entity) { super(entity); } @Override public InputStream getContent() throws IOException, IllegalStateException { // the wrapped entity's getContent() decides about repeatability InputStream wrappedin = wrappedEntity.getContent(); return new GZIPInputStream(wrappedin); } @Override public long getContentLength() { // length of ungzipped content is not known return -1; } } }(9)在代理中添加相关访问权限 DefaultHttpClient httpclient = new DefaultHttpClient(); httpclient.getCredentialsProvider().setCredentials( new AuthScope("localhost", 8080), new UsernamePasswordCredentials("username", "password")); HttpHost targetHost = new HttpHost("www.verisign.com", 443, "https"); HttpHost proxy = new HttpHost("localhost", 8080); httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy); HttpGet httpget = new HttpGet("/"); System.out.println("executing request: " + httpget.getRequestLine()); System.out.println("via proxy: " + proxy); System.out.println("to target: " + targetHost); HttpResponse response = httpclient.execute(targetHost, httpget);(10)针对特定的相应中信息比较多那么可以采用相关的相应处理器处理 ResponseHandler<String> responseHandler = new BasicResponseHandler(); String responseBody = httpclient.execute(httpget, responseHandler); 实现类如下： public class BasicResponseHandler implements ResponseHandler<String>关于HttpClient采用代理服务器的使用 // 创建两个host对象，其中一个目标机器，和代理主机make sure to use a proxy that supports CONNECT HttpHost target = new HttpHost("issues.apache.org", 443, "https"); HttpHost proxy = new HttpHost("127.0.0.1", 8080, "http"); //设置相关的注册信息 general setup SchemeRegistry supportedSchemes = new SchemeRegistry(); // Register the "http" and "https" protocol schemes, they are // required by the default operator to look up socket factories. supportedSchemes.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80)); supportedSchemes.register(new Scheme("https", SSLSocketFactory.getSocketFactory(), 443)); //设置相关的参数的信息 HttpParams params = new BasicHttpParams(); HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1); HttpProtocolParams.setContentCharset(params, "UTF-8"); HttpProtocolParams.setUseExpectContinue(params, true); //客户端连接管理器 ClientConnectionManager ccm = new ThreadSafeClientConnManager(params, supportedSchemes); DefaultHttpClient httpclient = new DefaultHttpClient(ccm, params); //设置请求采用代理的 httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy); HttpGet req = new HttpGet("/"); //执行请求并处理 System.out.println("executing request to " + target + " via " + proxy); HttpResponse rsp = httpclient.execute(target, req); HttpEntity entity = rsp.getEntity(); (11)针对多线程的Httpclient中采用的特殊的连接管理 // Create and initialize HTTP parameters HttpParams params = new BasicHttpParams(); ConnManagerParams.setMaxTotalConnections(params, 100); HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1); // Create and initialize scheme registry SchemeRegistry schemeRegistry = new SchemeRegistry(); schemeRegistry.register( new Scheme("http", PlainSocketFactory.getSocketFactory(), 80)); // Create an HttpClient with the ThreadSafeClientConnManager. // This connection manager must be used if more than one thread will // be using the HttpClient. ClientConnectionManager cm = new ThreadSafeClientConnManager(params, schemeRegistry); HttpClient httpClient = new DefaultHttpClient(cm, params);?