This java based tutorial is designed to provide a basic overview of how to use HttpClient.
Downloaded HttpClient and dependencies listed below that are required to put them on your classpath.
- httpclient-4.2.3.jar from http://hc.apache.org/downloads.cgi/li>
- commons-codec.jar from http://commons.apache.org/codec/
- commons-logging.jar from http://commons.apache.org/logging/
- junit.jar from http://www.junit.org/
The general process for using HttpClient consists of a number of steps:
- Create an instance of HttpClient.
- Create an instance of one of the methods (GetMethod in this case). The URL to connect to is passed in to the the method constructor.
- Tell HttpClient to execute the method.
- Read the response.
- Release the connection.
- Deal with the response.
package com.jkoder.http; import org.apache.http.HttpResponse; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.HttpClientBuilder; public class HttpClientExample { public static void main(String[] args) throws Exception { HttpClient client = new HttpClient(); GetMethod method = new GetMethod("jkoder.com"); // Provide custom retry handler is necessary method.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler(3, false)); try { // Execute the method. int statusCode = client.executeMethod(method); //If status code is not 200. if (statusCode != HttpStatus.SC_OK) { System.err.println("Method failed: " + method.getStatusLine()); } // Read the response body. byte[] responseBody = method.getResponseBody(); System.out.println(new String(responseBody)); } catch (HttpException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { method.releaseConnection(); } } }