1. 浏览器请求

2. 代码请求 

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.HttpURLConnection;
import java.URL;

public class CookieUtil {

    /**
     *
     * @param vrifyCodeUrl 验证码url
     * @return cookie
     */
    public static String getCookie(String vrifyCodeUrl) {
        String  cookie = "";
        ByteArrayOutputStream data = new ByteArrayOutputStream();
        try {
            // 创建URL
            URL url = new URL(vrifyCodeUrl);
            byte[] by = new byte[1024];
            // 创建链接
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setConnectTimeout(5000);
            InputStream is = conn.getInputStream();

            // 获取cookie 格式: JSESSIONID=A5B2A80BA310A146DCBC606E084E29D1
            cookie = "JSESSIONID="+conn.getHeaderField("set-cookie").split(";")[0].split("=")[1];
            System.out.println("Cookie:"+cookie);
            // 将内容读取内存中
            int len = -1;
            while ((len = is.read(by)) != -1) {
                data.write(by, 0, len);
            }
            // 关闭流
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return cookie;
    }

    public static void main(String[] args) {
        getCookie("http://xxxxx");
    }
}

输出:

Cookie:JSESSIONID=4964544B3CC5968EC3D387BAE31FA461