HttpClient3.x之Get请求和Post请求示例

最后更新于:2022-04-01 22:59:37

     版权声明:本文为博主原创文章,未经博主允许不得转载。如需转载请声明:【转自 http://blog.csdn.net/xiaoxian8023 】      HttpClient的支持在HTTP/1.1规范中定义的所有的HTTP方法:GET, HEAD, POST, PUT, DELETE, TRACE 和 OPTIONS。每有一个方法都有一个对应的类:HttpGet,HttpHead,HttpPost,HttpPut,HttpDelete,HttpTrace和HttpOptions。所有的这些类均实现了HttpUriRequest接口,故可以作为execute的执行参数使用。请求URI是能够应用请求的统一资源标识符。 HTTP请求的URI包含一个协议计划protocol scheme,主机名host name,,可选的端口optional port,资源的路径resource path,可选的查询optional query和可选的片段optional fragment。      head,put,delete,trace HttpClient支持这些方法, 大多数浏览器不支持这些方法,原因是Html 4中对 FORM 的method方法只支持两个get和post,很多浏览器还都依然是基于html4的。      通常会在JAVA中通过代码调用URL进行远端方法调用,这些方法有的是Get请求方式的,有的是POST请求方式的,为此,总结一例,贴出以便查阅。      依赖JAR包有:commons-codec.jar,commons-httpclient.jar,commons-logging.jar。 ~~~ package com.wujintao.httpclient; import java.io.IOException; import java.io.InputStream; import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.HttpException; import org.apache.commons.httpclient.HttpStatus; import org.apache.commons.httpclient.NameValuePair; import org.apache.commons.httpclient.methods.GetMethod; import org.apache.commons.httpclient.methods.PostMethod; import org.apache.commons.httpclient.params.HttpMethodParams; import org.junit.Test; public class TestCase { @Test public void testGetRequest() throws IllegalStateException, IOException { HttpClient client = new HttpClient(); StringBuilder sb = new StringBuilder(); InputStream ins = null; // Create a method instance. GetMethod method = new GetMethod("http://www.baidu.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); System.out.println(statusCode); if (statusCode == HttpStatus.SC_OK) { ins = method.getResponseBodyAsStream(); byte[] b = new byte[1024]; int r_len = 0; while ((r_len = ins.read(b)) > 0) { sb.append(new String(b, 0, r_len, method .getResponseCharSet())); } } else { System.err.println("Response Code: " + statusCode); } } catch (HttpException e) { System.err.println("Fatal protocol violation: " + e.getMessage()); } catch (IOException e) { System.err.println("Fatal transport error: " + e.getMessage()); } finally { method.releaseConnection(); if (ins != null) { ins.close(); } } System.out.println(sb.toString()); } @Test public void testPostRequest() throws HttpException, IOException { HttpClient client = new HttpClient(); PostMethod method = new PostMethod("http://www.baidu.com/getValue"); method.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=gb2312"); NameValuePair[] param = { new NameValuePair("age", "11"), new NameValuePair("name", "jay"), }; method.setRequestBody(param); int statusCode = client.executeMethod(method); System.out.println(statusCode); method.releaseConnection(); } } ~~~
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