《Apache HttpClient 4.3開發指南》

一、概述

Apache HttpClient 4系列已經發布很久了，但由於它與HttpClient 3.x版本完全不相容，以至於業內採用此庫的公司較少，在網際網路上也少有相關的文件資料分享。

本文旨在寫一個簡要的Apache HttpClient 4.3開發指南，幫助開發者快速上手Apache HttpClient 4.3.x庫。

要注意的是，本文件中的程式碼在低於HttpClient 4.3版本的地方可能不能執行。

二、開發手冊

CloseableHttpClient client = HttpClientBuilder.create().build();
 

instance.execute(new HttpGet(“http://www.baidu.com”));

String url = “http://www.baidu.com”;CloseableHttpResponse response = instance.execute(new HttpGet(url));assertThat(response.getStatusLine().getStatusCode(), equalTo(200));

String url = “http://www.baidu.com”;CloseableHttpResponse response = instance.execute(new
 
 HttpGet(url));String contentMimeType = ContentType.getOrDefault(response.getEntity()).getMimeType();assertThat(contentMimeType, equalTo(ContentType.TEXT_HTML.getMimeType()));

String url = “http://www.baidu.com”;CloseableHttpResponse response = instance.execute(new HttpGet(url));String bodyAsString = EntityUtils.toString(response.getEntity());assertThat(bodyAsString, notNullValue());
 

@Test(expected=SocketTimeoutException.class)public void givenLowTimeout_whenExecutingRequestWithTimeout_thenException() throws ClientProtocolException, IOException{    RequestConfig requestConfig = RequestConfig.custom() .setConnectionRequestTimeout(50).setConnectTimeout(50) .setSocketTimeout(50).build();    HttpGet request = new HttpGet(SAMPLE_URL);    request.setConfig(requestConfig);    instance.execute(request);}

instance.execute(new HttpPost(SAMPLE_URL));

CloseableHttpClient instance = HttpClientBuilder.create().disableRedirectHandling().build();CloseableHttpResponse response = instance.execute(new HttpGet(SAMPLE_URL));assertThat(reponse.getStatusLine().getStatusCode(), equalTo(301));

HttpGet request = new HttpGet(SAMPLE_URL);request.addHeader(HttpHeaders.ACCEPT, “application/xml”);response = instance.execute(request);

CloseableHttpResponse response = instance.execute(new HttpGet(SAMPLE_URL));Header[] headers = response.getHeaders(HttpHeaders.CONTENT_TYPE);assertThat(headers, not(emptyArray()));

response = instance.execute(new HttpGet(SAMPLE_URL));try{  HttpEntity entity = response.getEntity();  if(entity!=null){InputStream instream = entity.getContent();instream.close();  }} finally{  response.close();}