java使用httpclient模拟post请求和get请求示例

import java.io.bufferedreader;
import java.io.ioexception;
import java.io.inputstream;
import java.io.inputstreamreader;

import org.apache.commons.httpclient.defaulthttpmethodretryhandler;
import org.apache.commons.httpclient.header;
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.cookie.cookiepolicy;
import org.apache.commons.httpclient.methods.getmethod;
import org.apache.commons.httpclient.methods.postmethod;
import org.apache.commons.httpclient.params.httpmethodparams;

public class testhttpclient {

 public static void main(string[] args) {
  // todo auto-generated method stub
  //定义httpclient的实例
  httpclient httpclient = new httpclient();

  //创建get方法的实例
  getmethod getmethod = new getmethod("http://jb51.net");
  //使用系统提供的默认恢复策略
//  getmethod.getparams().setparameter(httpmethodparams.retry_handler, new defaulthttpmethodretryhandler());

  

  //创建post方法实例
  postmethod postmethod = new utf8postmethod("http://jb51.net");
//  
//  //填入各个表单域的值
//  namevaluepair[] data = {new namevaluepair("user_name", "user_name"),new namevaluepair("password","password")};
//  
//  //将表单的值放入到post方法中
//  postmethod.setrequestbody(data);
//  
//  postmethod.getparams().setparameter(
//    "http.protocol.cookie-policy",cookiepolicy.browser_compatibility);
//  postmethod.setrequestheader("referer", "http://jb51.net");
  try{
   //执行get方法
//   int statuscode = httpclient.executemethod(getmethod);

   //执行post方法
   int statuscode = httpclient.executemethod(postmethod);
   if(statuscode == httpstatus.sc_moved_temporarily){
    header locationheader = postmethod.getresponseheader("location");
    string location = null;
    if(locationheader != null){
     location = locationheader.getvalue();
    }
    postmethod = new postmethod(location);
    postmethod.setrequestheader("referer", "http://jb51.net/login");
    namevaluepair[] data1 = {new namevaluepair("user_name", "user_name"),new namevaluepair("password","password")};
    postmethod.setrequestbody(data1);
    postmethod.getparams().setparameter(
      "http.protocol.cookie-policy",cookiepolicy.browser_compatibility);
    int statuscode1 = httpclient.executemethod(postmethod);
    if(statuscode1 != httpstatus.sc_ok){
     system.out.println("method is wrong " + postmethod.getstatusline());
    }
   }
   if(statuscode != httpstatus.sc_ok){
    system.out.println("method is wrong " + postmethod.getstatusline());
   }
   inputstream responsebody = postmethod.getresponsebodyasstream();
   bufferedreader reader = new bufferedreader(new inputstreamreader(responsebody,"utf-8"));
   string line = reader.readline();
   while(line != null){
    system.out.println(new string(line.getbytes()));
    line = reader.readline();
   }

  }
  catch (httpexception e) {
   // todo: handle exception
   system.out.println("please check your provided http address!");
   e.printstacktrace();
  }catch (ioexception e) {
   // todo: handle exception
   system.out.println("the line is wrong!");
   e.printstacktrace();
  }finally{
   getmethod.releaseconnection();//释放链接
   postmethod.releaseconnection();
  }
 }
 //inner class for utf-8 support  
 public static class utf8postmethod extends postmethod{  
  public utf8postmethod(string url){  
  super(url);  
  }  
  @override  
  public string getrequestcharset() {  
   //return super.getrequestcharset();  
   return "utf-8";  
  }
 }

}