HttpClient 4.3详细教程之快速API
2017-07-14 15:27
344 查看
5.1. Easy to use facade API
HttpClient从4.2开始支持快速api。快速api仅仅实现了HttpClient的基本功能,它只要用于一些不需要灵活性的简单场景。例如,快速api不需要用户处理连接管理和资源释放。下面是几个使用快速api的例子:
[java] view
plaincopy
// Execute a GET with timeout settings and return response content as String.
Request.Get("http://somehost/")
.connectTimeout(1000)
.socketTimeout(1000)
.execute().returnContent().asString();
[java] view
plaincopy
// Execute a POST with the 'expect-continue' handshake, using HTTP/1.1,
// containing a request body as String and return response content as byte array.
Request.Post("http://somehost/do-stuff")
.useExpectContinue()
.version(HttpVersion.HTTP_1_1)
.bodyString("Important stuff", ContentType.DEFAULT_TEXT)
.execute().returnContent().asBytes();
[java] view
plaincopy
// Execute a POST with a custom header through the proxy containing a request body
// as an HTML form and save the result to the file
Request.Post("http://somehost/some-form")
.addHeader("X-Custom-header", "stuff")
.viaProxy(new HttpHost("myproxy", 8080))
.bodyForm(Form.form().add("username", "vip").add("password", "secret").build())
.execute().saveContent(new File("result.dump"));
如果需要在指定的安全上下文中执行某些请求,我们也可以直接使用Exector,这时候用户的认证信息就会被缓存起来,以便后续的请求使用。
[java] view
plaincopy
Executor executor = Executor.newInstance()
.auth(new HttpHost("somehost"), "username", "password")
.auth(new HttpHost("myproxy", 8080), "username", "password")
.authPreemptive(new HttpHost("myproxy", 8080));
executor.execute(Request.Get("http://somehost/"))
.returnContent().asString();
executor.execute(Request.Post("http://somehost/do-stuff")
.useExpectContinue()
.bodyString("Important stuff", ContentType.DEFAULT_TEXT))
.returnContent().asString();
5.1.1.
响应处理
一般情况下,HttpClient的快速api不用用户处理连接管理和资源释放。但是,这样的话,就必须在内存中缓存这些响应消息。为了避免这一情况,建议使用使用ResponseHandler来处理Http响应。[java] view
plaincopy
Document result = Request.Get("http://somehost/content")
.execute().handleResponse(new ResponseHandler<Document>() {
public Document handleResponse(final HttpResponse response) throws IOException {
StatusLine statusLine = response.getStatusLine();
HttpEntity entity = response.getEntity();
if (statusLine.getStatusCode() >= 300) {
throw new HttpResponseException(
statusLine.getStatusCode(),
statusLine.getReasonPhrase());
}
if (entity == null) {
throw new ClientProtocolException("Response contains no content");
}
DocumentBuilderFactory dbfac = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder docBuilder = dbfac.newDocumentBuilder();
ContentType contentType = ContentType.getOrDefault(entity);
if (!contentType.equals(ContentType.APPLICATION_XML)) {
throw new ClientProtocolException("Unexpected content type:" +
contentType);
}
String charset = contentType.getCharset();
if (charset == null) {
charset = HTTP.DEFAULT_CONTENT_CHARSET;
}
return docBuilder.parse(entity.getContent(), charset);
} catch (ParserConfigurationException ex) {
throw new IllegalStateException(ex);
} catch (SAXException ex) {
throw new ClientProtocolException("Malformed XML document", ex);
}
}
});
相关文章推荐
- HttpClient 4.3详细教程
- HttpClient 4.3详细教程之HTTP认证
- HttpClient 4.3详细教程
- HttpClient 4.3详细教程
- HttpClient 4.3详细教程之HTTP缓存
- HttpClient 4.3详细教程之基本概念
- HttpClient 4.3详细教程之连接管理
- HttpClient 4.3详细教程
- HttpClient 4.3详细教程之高级主题
- HttpClient 4.3详细教程之Http状态管理
- HttpClient 4.3详细教程
- HttpClient 4.3教程
- HttpClient 4.3教程 第一章 基本概念
- HttpClient 4.3教程
- HttpClient 4.3教程(转载)
- HttpClient4.3 教程 第五章 快速API
- HttpClient 4.3教程
- HttpClient 4.3教程(转载)
- HttpClient 4.3教程
- HttpClient 4.3教程 第六章 HTTP缓存