HttpClient3.x之Get请求和Post请求示例

来源：互联网发布：stm32单片机引脚图编辑：程序博客网时间：2024/06/05 04:07

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 {@Testpublic 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 necessarymethod.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());}@Testpublic 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();}}

1 0