使用Apache HttpClient访问JSP发送GET和POST请求

xiaui520

　　本示例说明了如何使用Apache HttpClient发送GET和POST请求，以及如何发送表单数据，详见代码及说明。对于ASP.NET的网站请求，可以查看使用Apache HttpClient访问ASP.NET发送GET和POST请求
　　说明：
　　1、发送表单POST请求时，需要借助HttpWatch或有这种功能的小工具来查看发给服务器的参数有哪些；
　　2、对于POST请求的表单数据，需要创建BasicNameValuePair对象的集合，然后构造成UrlEncodedFormEntity对象，再赋值到HttpPost对象的Entity中；
　　3、请求发送后可以使用response2.getStatusLine().getStatusCode()，获取HTTP的状态码；
　　4、使用HttpResponse对象的getHeaders("")或getAllHeaders方法可以获取相应头；
　　5、若要获取相应的内容，可以使用HttpResponse的getEntity()获取HttpEntity对象，然后再调用它的getContent()方法，获取一个输出流(InputStream对象)
　　Apache HttpClient 版本 4.0.3
　　下载地址：http://hc.apache.org/downloads.cgi

package com.zywang.http;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
/**
* 使用HttClient访问JSP示例
* @author ZYWANG
*/
public class HttpClientForJSP {
public static void main(String[] args)
throws ClientProtocolException, IOException {
HttpClient client = new DefaultHttpClient();
get(client,"http://localhost:8080/PMS");
loginPost(client);
client.getConnectionManager().shutdown();
}
/**
* 模拟POST请求
* @param client
* @throws UnsupportedEncodingException
* @throws IOException
* @throws ClientProtocolException
*/
private static void loginPost(HttpClient client)
throws UnsupportedEncodingException, IOException,
ClientProtocolException {
System.out.println("==========登录：====================================");
HttpPost post = new HttpPost("http://localhost:8080/PMS/LoginCheck.do");
//创建表单参数列表
List<NameValuePair> qparams = new ArrayList<NameValuePair>();
qparams.add(new BasicNameValuePair("method", "check"));
qparams.add(new BasicNameValuePair("userid", "zywang"));
qparams.add(new BasicNameValuePair("userpassword", "111111"));
//填充表单
post.setEntity(new UrlEncodedFormEntity(qparams,"UTF-8"));
HttpResponse response2 = client.execute(post);
int statusCode = response2.getStatusLine().getStatusCode();
System.out.println("statusCode:"+statusCode);
if(statusCode==200){
HttpEntity entity2 = response2.getEntity();
BufferedReader reader2 = new BufferedReader(
new InputStreamReader(entity2.getContent()));
String buffer2;
while((buffer2=reader2.readLine())!=null){
System.out.println(buffer2);
}
}else if(statusCode == 302){//302表示重定向
Header[] hs = response2.getHeaders("Location");
if(hs.length>0){
String url = hs[0].getValue();
post.abort();
get(client,url);
}
}
}
/**
* 模拟GET请求
* @param client
* @param url
* @throws IOException
* @throws ClientProtocolException
*/
private static void get(HttpClient client,String url) throws IOException,
ClientProtocolException {
System.out.println("======GET:"+url+"===========================");
HttpGet get = new HttpGet(url);
HttpResponse response = client.execute(get);
HttpEntity entity = response.getEntity();
BufferedReader reader = new BufferedReader(
new InputStreamReader(entity.getContent(),"UTF-8"));
String buffer = null;
while((buffer=reader.readLine())!=null){
System.out.println(buffer);
}
get.abort();
}
}