httpclient之httpcontext使用(代码片段)

@RestController
public class RequestController 
    @PostMapping("/request")
    public void request(HttpServletRequest request, HttpServletResponse response) 
        HttpSession session = request.getSession();
        //1. 从session中获取username
        String username = (String) session.getAttribute("username");
        String ret;
        if (username == null) 
            // 2. 从请求参数中获取username的值
            username = request.getParameter("username");
            session.setAttribute("username", username);
            ret = "login success!";
         else 
            ret = "Having been logined " + username;
        
        // 将ret 内容写回到response响应体中
        ServletOutputStream outputStream = null;
        PrintWriter pw = null;

        try 
            outputStream = response.getOutputStream();
            pw = new PrintWriter(outputStream);
            pw.write(ret);

         catch (IOException e) 
            e.printStackTrace();
         finally 
            if (pw != null) 
                pw.close();
            
            try 
                if (outputStream != null) 
                    outputStream.close();
                
             catch (IOException e) 
                e.printStackTrace();
            
        
    

import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class HttpContextTest 
    public static void main(String[] args) throws IOException 
        
        HttpContext httpContext = new BasicHttpContext();
        HttpClientContext httpClientContext = HttpClientContext.adapt(httpContext);
        
        CloseableHttpClient httpclient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost("http://localhost:9999/request");
        // 模仿form表单请求，设置请求参数
        List<NameValuePair> nvp = new ArrayList<>();
        nvp.add(new BasicNameValuePair("username", "admin"));
        // 第一次请求时，设置请求参数
        httpPost.setEntity(new UrlEncodedFormEntity(nvp));

        CloseableHttpResponse response = null;
        try 
            response = httpclient.execute(httpPost, httpClientContext);
            HttpEntity entity = response.getEntity();
            if (entity != null) 
                String ret = EntityUtils.toString(entity);
                System.out.println("第一次请求响应："+ ret);
            
        finally 
            response.close();
        

        System.out.println("=================第二次请求====================");
        // 重新创建一个HttpPost对象，但是此次该对象中不设置请求参数
        httpPost = new HttpPost("http://localhost:9999/request");
        try 
            response = httpclient.execute(httpPost, httpClientContext);
            HttpEntity entity = response.getEntity();
            if (entity != null) 
                String ret = EntityUtils.toString(entity);
                System.out.println("第二次请求响应："+ ret);
            
        finally 
            response.close();
        
    

第一次请求响应：login success!
=================第二次请求====================
第二次请求响应：Having been logined admin

Process finished with exit code 0

@Override
public void process(final HttpResponse response, final HttpContext context)
        throws HttpException, IOException 
 
    final HttpClientContext clientContext = HttpClientContext.adapt(context);

    // Obtain actual CookieSpec instance
    final CookieSpec cookieSpec = clientContext.getCookieSpec();
    // Obtain cookie store
    final CookieStore cookieStore = clientContext.getCookieStore();
    
    //.......
    // see if the cookie spec supports cookie versioning.
    if (cookieSpec.getVersion() > 0) 
        // process set-cookie2 headers.
        // Cookie2 will replace equivalent Cookie instances
        // 就是将cookie信息拷到cookieStore中
        it = response.headerIterator(SM.SET_COOKIE2);
        processCookies(it, cookieSpec, cookieOrigin, cookieStore);