采用apache 的httpclient工具进行http请求(保持session会话)
23小时前/**
* 采用apache httpclient工具，依赖jar包 common-codec common-log和 common-httpclient 都是apache的jar包
* cookice 原理，默认情况下，服务器会把session写在cookie里，所以禁用cookie会导致session丢失，若果吧session记录下来，
* 会保持session，当发现session过期时候，更新session，就能保证继续访问
* @author 于堃
*
*/
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.httpclient.Cookie;
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.methods.GetMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;
public class HttpUtil {
private static String DEFAULT_ENCODE="UTF-8";
private HttpClient httpClient = new HttpClient();
private Map<String,Cookie[]>history=new HashMap<String,Cookie[]>();
private Map<String,Cookie>sessions=new HashMap<String,Cookie>();
public String doGet(String url) throws HttpException, IOException
{
return doGet(url,DEFAULT_ENCODE);
}
public synchronized String doGet(String url,String encode)throws HttpException,IOException
{
String host=url.replaceFirst("\\w+://","");//正则表达式
int offset=host.indexOf("/");
if(offset!=-1)
{
host=host.substring(0,offset);
}
Cookie session=sessions.get(host);
GetMethod doGET =new GetMethod(url);
doGET.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
new DefaultHttpMethodRetryHandler());
if(session!=null)//保持会话
{
httpClient.getState().addCookie(session);
}
int statusCode = httpClient.executeMethod(doGET);
if (statusCode !=HttpStatus.SC_OK)
{
return null;
}
byte[] response = doGET.getResponseBody();
String response_str=new String(response,encode);
Cookie[] cookies =httpClient.getState().getCookies();
for(Cookie cookie:cookies)
{
String name=cookie.getName();
if(name.endsWith("SESSIONID"))
{
if(session==null||!session.getValue().equals(cookie.getValue()))
{
sessions.put(host, cookie); //会话过期，续期
}
}
}
doGET.releaseConnection();
return response_str;
}
}
原文地址:http://user.qzone.qq.com/253620527/blog/1303655583
