HttpComponents组件特性探究

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摘要  在Java领域,谈到网络编程,可能大家脑海里第一反应就是MINA,NETTY,GRIZZLY等优秀的开源框架。没错,不过在深入探究这些框架之前,我

  在Java领域,谈到网络编程,可能大家脑海里第一反应就是MINA,NETTY,GRIZZLY等优秀的开源框架。没错,不过在深入探究这些框架之前,我们需要先从最original的技术探究开始(当然,需要大家先熟悉java.net.*类库)。这里,我要和大家分享一下HttpComponents项目的部分组件特性。HttpClient,想必大家早都接触过了吧。HttpComponents和HttpClient的”血缘“有点像guava和google-collection的关系。目前,HttpComponents已经是Apache的顶级项目了,它旨在为我们提供一个Http协议相关的Java平台工具集。它的代码组织很精妙,主要分两部分,一部分是核心工具集(包括HttpCore-bio,HttpCore-nio,HttpClient,HttpMIme,HttpCookie等),一部分是扩展工具集(目前主要包括ssl)

  HttpClient主要包括Connection management,Status management,Authentication Management三部分。下面给出对它的二次封装,经过了线上的接近半年的验证(这里指的是httpClient 3,httpClient 4还有待检验),可以看做是一个高性能的Client封装吧。感兴趣的朋友可以根据apache的MPM IO模型进行部分参数的调整。文章源自玩技e族-https://www.playezu.com/204455.html

  先来段httpClient 4的封装,代码如下:文章源自玩技e族-https://www.playezu.com/204455.html

  [java] view plaincopyprint?文章源自玩技e族-https://www.playezu.com/204455.html

  /**文章源自玩技e族-https://www.playezu.com/204455.html

  * @author von gosling 2012-3-2文章源自玩技e族-https://www.playezu.com/204455.html

  */文章源自玩技e族-https://www.playezu.com/204455.html

  public class HttpComponentsClientExecutor implements DisposableBean {文章源自玩技e族-https://www.playezu.com/204455.html

  private static final int DEFAULT_MAX_TOTAL_CONNECTIONS = 100;文章源自玩技e族-https://www.playezu.com/204455.html

  private static final int DEFAULT_MAX_CONNECTIONS_PER_ROUTE = 5; //notice IE 6,7,8文章源自玩技e族-https://www.playezu.com/204455.html

  private static final int DEFAULT_CONN_TIMEOUT_MILLISECONDS = 5 * 1000;文章源自玩技e族-https://www.playezu.com/204455.html

  private static final int DEFAULT_READ_TIMEOUT_MILLISECONDS = 60 * 1000;

  private static final String HTTP_HEADER_CONTENT_ENCODING = "Content-Encoding";

  private static final String ENCODING_GZIP = "gzip";

  private HttpClient httpClient;

  /**

  * Create a new instance of the HttpComponentsClient with a default

  * {@link HttpClient} that uses a default

  * {@link org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager}.

  */

  public HttpComponentsClientExecutor() {

  SchemeRegistry schemeRegistry = new SchemeRegistry();

  schemeRegistry.register(new Scheme("http", 80, PlainSocketFactory.getSocketFactory()));

  schemeRegistry.register(new Scheme("https", 443, SSLSocketFactory.getSocketFactory()));

  ThreadSafeClientConnManager connectionManager = new ThreadSafeClientConnManager(

  schemeRegistry);

  connectionManager.setMaxTotal(DEFAULT_MAX_TOTAL_CONNECTIONS);

  connectionManager.setDefaultMaxPerRoute(DEFAULT_MAX_CONNECTIONS_PER_ROUTE);

  this.httpClient = new DefaultHttpClient(connectionManager);

  setConnectTimeout(DEFAULT_CONN_TIMEOUT_MILLISECONDS);

  setReadTimeout(DEFAULT_READ_TIMEOUT_MILLISECONDS);

  }

  /**

  * Create a new instance of the HttpComponentsClient with the given

  * {@link HttpClient} instance.

  *

  * @param httpClient the HttpClient instance to use for this request

  */

  public HttpComponentsClientExecutor(HttpClient httpClient) {

  Validate.notNull(httpClient, "HttpClient must not be null");

  //notice: if you want to custom exception recovery mechanism

  //you should provide an implementation of the HttpRequestRetryHandler interface.

  this.httpClient = httpClient;

  }

  /**

  * Set the {@code HttpClient} used by this request.

  */

  public void setHttpClient(HttpClient httpClient) {

  this.httpClient = httpClient;

  }

  /**

  * Return the {@code HttpClient} used by this request.

  */

  public HttpClient getHttpClient() {

  return this.httpClient;

  }

  /**

  * Set the connection timeout for the underlying HttpClient. A timeout value

  * of 0 specifies an infinite timeout.

  *

  * @param timeout the timeout value in milliseconds

  */

  public void setConnectTimeout(int timeout) {

  Validate.isTrue(timeout >= 0, "Timeout must be a non-negative value");

  getHttpClient().getParams().setIntParameter(CoreConnectionPNames.CONNECTION_TIMEOUT,

  timeout);

  }

  /**

  * Set the socket timeout (SO_TIMEOUT) in milliseconds, which is the timeout

  * for waiting for data or, put differently, a maximum period inactivity

  * between two consecutive data packets.A timeout value of 0 specifies an

  * infinite timeout.

  *

  * @param timeout the timeout value in milliseconds

  */

  public void setReadTimeout(int timeout) {

  Validate.isTrue(timeout >= 0, "Timeout must be a non-negative value");

  getHttpClient().getParams().setIntParameter(CoreConnectionPNames.SO_TIMEOUT, timeout);

  }

  /**

  * Create a Commons HttpMethodBase object for the given HTTP method and URI

  * specification.

  *

  * @param httpMethod the HTTP method

  * @param uri the URI

  * @return the Commons HttpMethodBase object

  */

  protected HttpUriRequest createHttpUriRequest(HttpMethod httpMethod, URI uri) {

  switch (httpMethod) {

  case GET:

  return new HttpGet(uri);

  case DELETE:

  return new HttpDelete(uri);

  case HEAD:

  return new HttpHead(uri);

  case OPTIONS:

  return new HttpOptions(uri);

  case POST:

  return new HttpPost(uri);

  case PUT:

  return new HttpPut(uri);

  case TRACE:

  return new HttpTrace(uri);

  default:

  throw new IllegalArgumentException("Invalid HTTP method: " + httpMethod);

  }

  }

  /**

  * Execute the given method on the provided URI.

  *

  * @param method the HTTP method to execute (GET, POST, etc.)

  * @param url the fully-expanded URL to connect to

  * @param responseHandler httpClient will automatically take care of

  * ensuring release of the connection back to the connection

  * manager regardless whether the request execution succeeds or

  * causes an exception,if using this response handler

  * @return an response object's string representation

  * @throws IOException

  * @throws ClientProtocolException

  */

  public String doExecuteRequest(HttpMethod httpMethod, URI uri,

  ResponseHandler responseHandler)

  throws ClientProtocolException, IOException {

  return httpClient.execute(createHttpUriRequest(httpMethod, uri), responseHandler);

  }

  public InputStream doExecuteRequest(HttpMethod httpMethod, URI uri)

  throws ClientProtocolException, IOException {

  //1.

  HttpUriRequest httpUriRequest = createHttpUriRequest(httpMethod, uri);

  //2.

  HttpResponse response = httpClient.execute(httpUriRequest);

  //3.

  validateResponse(response);

  //4.

  return getResponseBody(response);

  }

  /**

  * Validate the given response, throwing an exception if it does not

  * correspond to a successful HTTP response.

  *

  * Default implementation rejects any HTTP status code beyond 2xx, to avoid

  * parsing the response body and trying to deserialize from a corrupted

  * stream.

  *

  * @param config the HTTP invoker configuration that specifies the target

  * service

  * @param response the resulting HttpResponse to validate

  * @throws NoHttpResponseException

  * @throws java.io.IOException if validation failed

  */

  protected void validateResponse(HttpResponse response) throws IOException {

  StatusLine status = response.getStatusLine();

  if (status.getStatusCode() >= 300) {

  throw new NoHttpResponseException(

  "Did not receive successful HTTP response: status code = "

  + status.getStatusCode() + ", status message = ["

  + status.getReasonPhrase() + "]");

  }

  }

  /**

  * Extract the response body

  *

  * The default implementation simply fetches the response body stream. If

  * the response is recognized as GZIP response, the InputStream will get

  * wrapped in a GZIPInputStream.

  *

  * @param httpResponse the resulting HttpResponse to read the response body

  * from

  * @return an InputStream for the response body

  * @throws java.io.IOException if thrown by I/O methods

  * @see #isGzipResponse

  * @see java.util.zip.GZIPInputStream

  */

  protected InputStream getResponseBody(HttpResponse httpResponse) throws IOException {

  if (isGzipResponse(httpResponse)) {

  return new GZIPInputStream(httpResponse.getEntity().getContent());

  } else {

  return httpResponse.getEntity().getContent();

  }

  }

  /**

  * Determine whether the given response indicates a GZIP response.

  *

  * The default implementation checks whether the HTTP "Content-Encoding"

  * header contains "gzip" (in any casing).

  *

  * @param httpResponse the resulting HttpResponse to check

  * @return whether the given response indicates a GZIP response

  */

  protected boolean isGzipResponse(HttpResponse httpResponse) {

  Header encodingHeader = httpResponse.getFirstHeader(HTTP_HEADER_CONTENT_ENCODING);

  return (encodingHeader != null && encodingHeader.getValue() != null && encodingHeader

  .getValue().toLowerCase().contains(ENCODING_GZIP));

  }

  /**

  * Shutdown hook that closes the underlying

  * {@link org.apache.http.conn.ClientConnectionManager

  * ClientConnectionManager}'s connection pool, if any.

  */

  public void destroy() {

  getHttpClient().getConnectionManager().shutdown();

  }

  enum HttpMethod {

  GET,

  POST,

  HEAD,

  OPTIONS,

  PUT,

  DELETE,

  TRACE

  }

  }

  /**

  * @author von gosling 2012-3-2

  */

  public class HttpComponentsClientExecutor implements DisposableBean {

  private static final int DEFAULT_MAX_TOTAL_CONNECTIONS = 100;

  private static final int DEFAULT_MAX_CONNECTIONS_PER_ROUTE = 5; //notice IE 6,7,8

  private static final int DEFAULT_CONN_TIMEOUT_MILLISECONDS = 5 * 1000;

  private static final int DEFAULT_READ_TIMEOUT_MILLISECONDS = 60 * 1000;

  private static final String HTTP_HEADER_CONTENT_ENCODING = "Content-Encoding";

  private static final String ENCODING_GZIP = "gzip";

  private HttpClient httpClient;

  /**

  * Create a new instance of the HttpComponentsClient with a default

  * {@link HttpClient} that uses a default

  * {@link org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager}.

  */

  public HttpComponentsClientExecutor() {

  SchemeRegistry schemeRegistry = new SchemeRegistry();

  schemeRegistry.register(new Scheme("http", 80, PlainSocketFactory.getSocketFactory()));

  schemeRegistry.register(new Scheme("https", 443, SSLSocketFactory.getSocketFactory()));

  ThreadSafeClientConnManager connectionManager = new ThreadSafeClientConnManager(

  schemeRegistry);

  connectionManager.setMaxTotal(DEFAULT_MAX_TOTAL_CONNECTIONS);

  connectionManager.setDefaultMaxPerRoute(DEFAULT_MAX_CONNECTIONS_PER_ROUTE);

  this.httpClient = new DefaultHttpClient(connectionManager);

  setConnectTimeout(DEFAULT_CONN_TIMEOUT_MILLISECONDS);

  setReadTimeout(DEFAULT_READ_TIMEOUT_MILLISECONDS);

  }

  /**

  * Create a new instance of the HttpComponentsClient with the given

  * {@link HttpClient} instance.

  *

  * @param httpClient the HttpClient instance to use for this request

  */

  public HttpComponentsClientExecutor(HttpClient httpClient) {

  Validate.notNull(httpClient, "HttpClient must not be null");

  //notice: if you want to custom exception recovery mechanism

  //you should provide an implementation of the HttpRequestRetryHandler interface.

  this.httpClient = httpClient;

  }

  /**

  * Set the {@code HttpClient} used by this request.

  */

  public void setHttpClient(HttpClient httpClient) {

  this.httpClient = httpClient;

  }

  /**

  * Return the{@code HttpClient} used by this request.

  */

  public HttpClient getHttpClient() {

  return this.httpClient;

  }

  /**

  * Set the connection timeout for the underlying HttpClient. A timeout value

  * of 0 specifies an infinite timeout.

  *

  * @param timeout the timeout value in milliseconds

  */

  public void setConnectTimeout(int timeout) {

  Validate.isTrue(timeout >= 0, "Timeout must be a non-negative value");

  getHttpClient().getParams().setIntParameter(CoreConnectionPNames.CONNECTION_TIMEOUT,

  timeout);

  }

  /**

  * Set the socket timeout (SO_TIMEOUT) in milliseconds, which is the timeout

  * for waiting for data or, put differently, a maximum period inactivity

  * between two consecutive data packets.A timeout value of 0 specifies an

  * infinite timeout.

  *

  * @param timeout the timeout value in milliseconds

  */

  public void setReadTimeout(int timeout) {

  Validate.isTrue(timeout >= 0, "Timeout must be a non-negative value");

  getHttpClient().getParams().setIntParameter(CoreConnectionPNames.SO_TIMEOUT, timeout);

  }

  /**

  * Create a Commons HttpMethodBase object for the given HTTP method and URI

  * specification.

  *

  * @param httpMethod the HTTP method

  * @param uri the URI

  * @return the Commons HttpMethodBase object

  */

  protected HttpUriRequest createHttpUriRequest(HttpMethod httpMethod, URI uri) {

  switch (httpMethod) {

  case GET:

  return new HttpGet(uri);

  case DELETE:

  return new HttpDelete(uri);

  case HEAD:

  return new HttpHead(uri);

  case OPTIONS:

  return new HttpOptions(uri);

  case POST:

  return new HttpPost(uri);

  case PUT:

  return new HttpPut(uri);

  case TRACE:

  return new HttpTrace(uri);

  default:

  throw new IllegalArgumentException("Invalid HTTP method: " + httpMethod);

  }

  }

  /**

  * Execute the given method on the provided URI.

  *

  * @param method the HTTP method to execute (GET, POST, etc.)

  * @param url the fully-expanded URL to connect to

  * @param responseHandler httpClient will automatically take care of

  * ensuring release of the connection back to the connection

  * manager regardless whether the request execution succeeds or

  * causes an exception,if using this response handler

  * @return an response object's string representation

  * @throws IOException

  * @throws ClientProtocolException

  */

  public String doExecuteRequest(HttpMethod httpMethod, URI uri,

  ResponseHandler responseHandler)

  throws ClientProtocolException, IOException {

  return httpClient.execute(createHttpUriRequest(httpMethod, uri), responseHandler);

  }

  public InputStream doExecuteRequest(HttpMethod httpMethod, URI uri)

  throws ClientProtocolException, IOException {

  //1.

  HttpUriRequest httpUriRequest = createHttpUriRequest(httpMethod, uri);

  //2.

  HttpResponse response = httpClient.execute(httpUriRequest);

  //3.

  validateResponse(response);

  //4.

  return getResponseBody(response);

  }

  /**

  * Validate the given response, throwing an exception if it does not

  * correspond to a successful HTTP response.

  *

  * Default implementation rejects any HTTP status code beyond 2xx, to avoid

  * parsing the response body and trying to deserialize from a corrupted

  * stream.

  *

  * @param config the HTTP invoker configuration that specifies the target

  * service

  * @param response the resulting HttpResponse to validate

  * @throws NoHttpResponseException

  * @throws java.io.IOException if validation failed

  */

  protected void validateResponse(HttpResponse response) throws IOException {

  StatusLine status = response.getStatusLine();

  if (status.getStatusCode() >= 300) {

  throw new NoHttpResponseException(

  "Did not receive successful HTTP response: status code = "

  + status.getStatusCode() + ", status message = ["

  + status.getReasonPhrase() + "]");

  }

  }

  /**

  * Extract the response body

  *

  * The default implementation simply fetches the response body stream. If

  * the response is recognized as GZIP response, the InputStream will get

  * wrapped in a GZIPInputStream.

  *

  * @param httpResponse the resulting HttpResponse to read the response body

  * from

  * @return an InputStream for the response body

  * @throws java.io.IOException if thrown by I/O methods

  * @see #isGzipResponse

  * @see java.util.zip.GZIPInputStream

  */

  protected InputStream getResponseBody(HttpResponse httpResponse) throws IOException {

  if (isGzipResponse(httpResponse)) {

  return new GZIPInputStream(httpResponse.getEntity().getContent());

  } else {

  return httpResponse.getEntity().getContent();

  }

  }

  /**

  * Determine whether the given response indicates a GZIP response.

  *

  * The default implementation checks whether the HTTP "Content-Encoding"

  * header contains "gzip" (in any casing).

  *

  * @param httpResponse the resulting HttpResponse to check

  * @return whether the given response indicates a GZIP response

  */

  protected boolean isGzipResponse(HttpResponse httpResponse) {

  Header encodingHeader = httpResponse.getFirstHeader(HTTP_HEADER_CONTENT_ENCODING);

  return (encodingHeader != null && encodingHeader.getValue() != null && encodingHeader

  .getValue().toLowerCase().contains(ENCODING_GZIP));

  }

  /**

  * Shutdown hook that closes the underlying

  *{@link }org.apache.http.conn.ClientConnectionManager

  * ClientConnectionManager}'s connection pool, if any.

  */

  public void destroy() {

  getHttpClient().getConnectionManager().shutdown();

  }

  enum HttpMethod {

  GET,

  POST,

  HEAD,

  OPTIONS,

  PUT,

  DELETE,

  TRACE

  }

  }

  下面是久经考验的httpClient 3的二次封装,如下:

  [java] view plaincopyprint?

  /**

  * @author von gosling 2011-12-12

  */

  public class HttpClientUtils {

  private static final Logger log = LoggerFactory

  .getLogger(HttpClientUtils.class);

  private static int timeOut = 100;

  private static int retryCount = 1;

  private static int connectionTimeout = 100;

  private static int maxHostConnections = 32; //根据apache work MPM设置此值

  private static int maxTotalConnections = 512; //同上

  private static String charsetName = "UTF-8";

  public static JSONObject executeMethod(HttpClient httpClient, HttpMethod method) {

  JSONObject result = new JSONObject();

  StopWatch watch = new StopWatch();

  int status = -1;

  try {

  log.info("Execute method({}) begin...", method.getURI());

  watch.start();

  status = httpClient.executeMethod(method);

  watch.stop();

  if (status == HttpStatus.SC_OK) {

  InputStream inputStream = method.getResponseBodyAsStream();

  ByteArrayOutputStream baos = new ByteArrayOutputStream();

  IOUtils.copy(inputStream, baos);

  String response = new String(baos.toByteArray(), charsetName);

  log.info("Response is:{}", response);

  result = JSONObject.parseObject(response);

  } else {

  log.error("Http request failure! status is {}", status);

  }

  } catch (SocketTimeoutException e) {

  log.error("Request time out!");//只关注请求超时,对于其它两类超时,使用通用异常捕获

  } catch (Exception e) {

  log.error("Error occur!", e);

  } finally {

  method.releaseConnection();

  log.info("Method {},statusCode {},consuming {} ms", new Object[] { method.getName(),

  status, watch.getTime()

  }

  return result;

  }

  /**

  * @param uri

  * @param nameValuePairs

  * @return

  */

  public static PostMethod createPostMethod(String uri, NameValuePair[] nameValuePairs) {

  PostMethod method = new PostMethod(uri);

  method.addParameters(nameValuePairs);

  method.getParams().setContentCharset(charsetName);

  return method;

  }

  /**

  * @param uri

  * @param nameValuePairs

  * @return

  */

  public static GetMethod createGetMethod(String uri, NameValuePair[] nameValuePairs) {

  GetMethod method = new GetMethod(uri);

  List list = Lists.newArrayList();

  if (nameValuePairs != null) {

  Collections.addAll(list, nameValuePairs);

  method.setQueryString(list.toArray(new NameValuePair[nameValuePairs.length]));

  }

  method.getParams().setContentCharset(charsetName);

  return method;

  }

  public static HttpClient createHttpClient() {

  //1.

  HttpClient httpClient = new HttpClient(new MultiThreadedHttpConnectionManager());

  //2.

  HttpConnectionManagerParams httpConnectionManagerParams = httpClient

  .getHttpConnectionManager().getParams();

  httpConnectionManagerParams.setConnectionTimeout(connectionTimeout);

  httpConnectionManagerParams.setTcpNoDelay(true);//Nagle's algorithm

  httpConnectionManagerParams.setSoTimeout(timeOut);

  httpConnectionManagerParams.setDefaultMaxConnectionsPerHost(maxHostConnections);

  httpConnectionManagerParams.setMaxTotalConnections(maxTotalConnections);

  //3.

  HttpClientParams httpClientParam = httpClient.getParams();

  //httpClientParam.setConnectionManagerTimeout(connectionTimeout);//暂且不关注这个超时设置,后面根据性能酌情考虑

  httpClientParam.setParameter(HttpMethodParams.RETRY_HANDLER,

  new DefaultHttpMethodRetryHandler(retryCount, false));

  httpClientParam.setCookiePolicy(CookiePolicy.BROWSER_COMPATIBILITY);

  return httpClient;

  }

  public static JSONObject doGet(String url, NameValuePair[] params) {

  return executeMethod(createHttpClient(), createGetMethod(url, params));

  }

  public static JSONObject doPost(String url, NameValuePair[] params) {

  return executeMethod(createHttpClient(), createPostMethod(url, params));

  }

  protected HttpClientUtils() {

  }

  public void setTimeOut(int timeOut) {

  HttpClientUtils.timeOut = timeOut;

  }

  public static int getTimeOut() {

  return timeOut;

  }

  public static int getRetryCount() {

  return retryCount;

  }

  public void setRetryCount(int retryCount) {

  HttpClientUtils.retryCount = retryCount;

  }

  public static int getConnectionTimeout() {

  return connectionTimeout;

  }

  public void setConnectionTimeout(int connectionTimeout) {

  HttpClientUtils.connectionTimeout = connectionTimeout;

  }

  public static int getMaxHostConnections() {

  return maxHostConnections;

  }

  public void setMaxHostConnections(int maxHostConnections) {

  HttpClientUtils.maxHostConnections = maxHostConnections;

  }

  public static int getMaxTotalConnections() {

  return maxTotalConnections;

  }

  public void setMaxTotalConnections(int maxTotalConnections) {

  HttpClientUtils.maxTotalConnections = maxTotalConnections;

  }

  public static String getCharsetName() {

  return charsetName;

  }

  public void setCharsetName(String charsetName) {

  HttpClientUtils.charsetName = charsetName;

  }

  }

  /**

  * @author von gosling 2011-12-12

  */

  public class HttpClientUtils {

  private static final Logger log = LoggerFactory

  .getLogger(HttpClientUtils.class);

  private static int timeOut = 100;

  private static int retryCount = 1;

  private static int connectionTimeout = 100;

  private static int maxHostConnections = 32; //根据apache work MPM设置此值

  private static int maxTotalConnections = 512; //同上

  private static String charsetName = "UTF-8";

  public static JSONObject executeMethod(HttpClient httpClient, HttpMethod method) {

  JSONObject result = new JSONObject();

  StopWatch watch = new StopWatch();

  int status = -1;

  try {

  log.info("Execute method({}) begin...", method.getURI());

  watch.start();

  status = httpClient.executeMethod(method);

  watch.stop();

  if (status == HttpStatus.SC_OK) {

  InputStream inputStream = method.getResponseBodyAsStream();

  ByteArrayOutputStream baos = new ByteArrayOutputStream();

  IOUtils.copy(inputStream, baos);

  String response = new String(baos.toByteArray(), charsetName);

  log.info("Response is:{}", response);

  result = JSONObject.parseObject(response);

  } else {

  log.error("Http request failure! status is {}", status);

  }

  } catch (SocketTimeoutException e) {

  log.error("Request time out!");//只关注请求超时,对于其它两类超时,使用通用异常捕获

  } catch (Exception e) {

  log.error("Error occur!", e);

  } finally {

  method.releaseConnection();

  log.info("Method {},statusCode {},consuming {} ms", new Object[] { method.getName(),

  status, watch.getTime()

  }

  return result;

  }

  /**

  * @param uri

  * @param nameValuePairs

  * @return

  */

  public static PostMethod createPostMethod(String uri, NameValuePair[] nameValuePairs) {

  PostMethod method = new PostMethod(uri);

  method.addParameters(nameValuePairs);

  method.getParams().setContentCharset(charsetName);

  return method;

  }

  /**

  * @param uri

  * @param nameValuePairs

  * @return

  */

  public static GetMethod createGetMethod(String uri, NameValuePair[] nameValuePairs) {

  GetMethod method = new GetMethod(uri);

  List list = Lists.newArrayList();

  if (nameValuePairs != null) {

  Collections.addAll(list, nameValuePairs);

  method.setQueryString(list.toArray(new NameValuePair[nameValuePairs.length]));

  }

  method.getParams().setContentCharset(charsetName);

  return method;

  }

  public static HttpClient createHttpClient() {

  //1.

  HttpClient httpClient = new HttpClient(new MultiThreadedHttpConnectionManager());

  //2.

  HttpConnectionManagerParams httpConnectionManagerParams = httpClient

  .getHttpConnectionManager().getParams();

  httpConnectionManagerParams.setConnectionTimeout(connectionTimeout);

  httpConnectionManagerParams.setTcpNoDelay(true);//Nagle's algorithm

  httpConnectionManagerParams.setSoTimeout(timeOut);

  httpConnectionManagerParams.setDefaultMaxConnectionsPerHost(maxHostConnections);

  httpConnectionManagerParams.setMaxTotalConnections(maxTotalConnections);

  //3.

  HttpClientParams httpClientParam = httpClient.getParams();

  //httpClientParam.setConnectionManagerTimeout(connectionTimeout);//暂且不关注这个超时设置,后面根据性能酌情考虑

  httpClientParam.setParameter(HttpMethodParams.RETRY_HANDLER,

  new DefaultHttpMethodRetryHandler(retryCount, false));

  httpClientParam.setCookiePolicy(CookiePolicy.BROWSER_COMPATIBILITY);

  return httpClient;

  }

  public static JSONObject doGet(String url, NameValuePair[] params) {

  return executeMethod(createHttpClient(), createGetMethod(url, params));

  }

  public static JSONObject doPost(String url, NameValuePair[] params) {

  return executeMethod(createHttpClient(), createPostMethod(url, params));

  }

  protected HttpClientUtils() {

  }

  public void setTimeOut(int timeOut) {

  HttpClientUtils.timeOut = timeOut;

  }

  public static int getTimeOut() {

  return timeOut;

  }

  public static int getRetryCount() {

  return retryCount;

  }

  public void setRetryCount(int retryCount) {

  HttpClientUtils.retryCount = retryCount;

  }

  public static int getConnectionTimeout() {

  return connectionTimeout;

  }

  public void setConnectionTimeout(int connectionTimeout) {

  HttpClientUtils.connectionTimeout = connectionTimeout;

  }

  public static int getMaxHostConnections() {

  return maxHostConnections;

  }

  public void setMaxHostConnections(int maxHostConnections) {

  HttpClientUtils.maxHostConnections = maxHostConnections;

  }

  public static int getMaxTotalConnections() {

  return maxTotalConnections;

  }

  public void setMaxTotalConnections(int maxTotalConnections) {

  HttpClientUtils.maxTotalConnections = maxTotalConnections;

  }

  public static String getCharsetName() {

  return charsetName;

  }

  public void setCharsetName(String charsetName) {

  HttpClientUtils.charsetName = charsetName;

  }

  }

  好了,有了活生生的代码,我们来总结一下httpClient封装过程中需要注意的一些事项吧。恩,其实更多的是体现在安全,性能上面:

  (1)多线程模型,尤其注意finally中collection的释放问题。除此之外,需要考虑池化连接的异常处理,这是我文中提到特别注意的三大异常之一;

  (2)Retry机制中对幂等性的处理。尤其是在httpClient4中,put和post操作,未按照http规范行事,需要我们额外注意;

  (3)SSL、TLS的定制化处理;

  (4)并发标记的处理,这里使用了Concurrency in practice中的并发annotation,有什么用?感兴趣的朋友可以了解下SureLogic,别问我要license,因为俺也不是apache开源社区的developer呀;

  (5)拦截器对header的处理;

  (6)collection stale check机制;

  (7)Cookie specification choose或者是自定义实现;

 
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