博客

第一次登录服务器返回的header中包含Set-Cookie，如果是浏览器请求，则浏览器会自动保存cookie，后续请求也会将Cookie放到请求header中

如图



而现在的客户端是java，则可以通过HttpClient实现

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.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class HttpSendUtils {

    public static String post(String url,Map<String,String> params,Map<String,String> headers) {
        CloseableHttpClient client = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost(url);
        UrlEncodedFormEntity entity;
        List<NameValuePair> paramPairs = new ArrayList<NameValuePair>();
        if(params!=null){
            for(Map.Entry<String,String> en:params.entrySet()){
                paramPairs.add(new BasicNameValuePair(en.getKey(), en.getValue()));
            }
        }
        if(headers!=null){
            for(Map.Entry<String,String> en:headers.entrySet()){
                httpPost.setHeader(en.getKey(), en.getValue());
            }
        }
        try {
            entity = new UrlEncodedFormEntity(paramPairs, "UTF-8");
            httpPost.setEntity(entity);
            HttpResponse resp = client.execute(httpPost);
            HttpEntity respEntity = resp.getEntity();
            if (null != respEntity) {
                return EntityUtils.toString(respEntity, "UTF-8");
            }

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                client.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    public static String get(String url,Map<String,String> headers) {
        CloseableHttpClient client = HttpClients.createDefault();
        HttpGet httpGet = new HttpGet(url);
        if(headers!=null){
            for(Map.Entry<String,String> en:headers.entrySet()){
                httpGet.setHeader(en.getKey(), en.getValue());
            }
        }
        try {
            HttpResponse resp = client.execute(httpGet);
            HttpEntity respEntity = resp.getEntity();
            if (null != respEntity) {
                return EntityUtils.toString(respEntity, "UTF-8");
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                client.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    public static void main(String[] args) {
        Map<String,String> params=new HashMap<>();
        params.put("username","admin");
        params.put("passwd","123456");
        System.out.println(HttpSendUtils.post("http://localhost:80/api/v1/login",params,null));
        //通过header拿到 Set-Cookie: JSESSIONID=63A57DF0215501C6CF6558817D664FBF;
        Map<String,String> headers=new HashMap<>();
        headers.put("Cookie","JSESSIONID=63A57DF0215501C6CF6558817D664FBF");
        System.out.println(HttpSendUtils.get("http://localhost:80/api/v1/logout",headers));
    }

}

maven包

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.4</version>
</dependency>