httpclient重新導向之後擷取網址資訊樣本_java

複製代碼 代碼如下:

import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.entity.ContentType;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.EntityUtils;

public class HttpClientDemo {

 /**
  * 擷取重新導向之後的網址資訊
  * @see HttpClient預設會自動處理用戶端重新導向
  * @see 即訪問網頁A後,假設被重新導向到了B網頁,那麼HttpClient將自動返回B網頁的內容
  * @see 若想取得B網頁的地址,就需要藉助HttpContext對象,HttpContext實際上是用戶端用來在多次請求響應的互動中,保持狀態資訊的
  * @see 我們自己也可以利用HttpContext來存放一些我們需要的資訊,以便下次請求的時候能夠取出這些資訊來使用
  */
 public static void getRedirectInfo(){
  HttpClient httpClient = new DefaultHttpClient();
  HttpContext httpContext = new BasicHttpContext();
  HttpGet httpGet = new HttpGet("http://127.0.0.1:8088/blog/main.jsp");
  try {
   //將HttpContext對象作為參數傳給execute()方法,則HttpClient會把請求響應互動過程中的狀態資訊儲存在HttpContext中
   HttpResponse response = httpClient.execute(httpGet, httpContext);
   //擷取重新導向之後的主機地址資訊,即"http://127.0.0.1:8088"
   HttpHost targetHost = (HttpHost)httpContext.getAttribute(ExecutionContext.HTTP_TARGET_HOST);
   //擷取實際的請求對象的URI,即重新導向之後的"/blog/admin/login.jsp"
   HttpUriRequest realRequest = (HttpUriRequest)httpContext.getAttribute(ExecutionContext.HTTP_REQUEST);
   System.out.println("主機地址:" + targetHost);
   System.out.println("URI資訊:" + realRequest.getURI());
   HttpEntity entity = response.getEntity();
   if(null != entity){
    System.out.println("響應內容:" + EntityUtils.toString(entity, ContentType.getOrDefault(entity).getCharset()));
    EntityUtils.consume(entity);
   }
  } catch (Exception e) {
   e.printStackTrace();
  }finally{
   httpClient.getConnectionManager().shutdown();
  }
 }
}