1. 代码部分参考

http://blog.csdn.net/github_37603222/article/details/78968887?utm_source=debugrun&utm_medium=referral

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;

public class Main {

    static String post="POST http://172.20.13.100:804/include/auth_action.php HTTP/1.1\n" +
            "Host: 172.20.13.100:804\n" +
            "User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0\n" +
            "Accept: */*\n" +
            "Accept-Language: zh-CN,zh;q=0.8,en-US;q=0.5,en;q=0.3\n" +
            "Accept-Encoding: gzip, deflate\n" +
            "Referer: http://172.20.13.100:804/srun_portal_pc.php?ac_id=18&\n" +
            "Content-Type: application/x-www-form-urlencoded\n" +
            "Content-Length: 99\n" +
            "Cookie: login=bQ0qQMxJvKa38joL2%252FjcHkC%252BmsG82yAvS0XGTkaUAqITzf1C1XjH0LBH3DvAVoqeDXiIyWwHluykns%252FbYtUUak1GPGqqZWFUnrgNFh3G6YRHOC3YK%252FNVgmMajbXNeOR0D%252B4olYy7aZwyNOm25ziIo1d%252BXXOAIuTVMqcPNt6JKFMANvY1f2yLD%252F7RXZuPjQVkeFeCU%252Fsbv0kNiKY%253D; login=bQ0qQMxJvKa38joL2%252FjcHkC%252BmsG82yAvS0XGTkaUAqITzf1C1XjH0LBH3DvAVoqeDXiIyWwHluykns%252FbYtUUak1GPGqqZWFUnrgNFh3G6YRHOC3YK%252FNVgmMajbXNeOR0D%252B4olYy7aZwyNOm25ziIo1d%252BXXOAIuTVMqcPNt6JKFMANvY1f2yLD%252F7RXZuPjQVkeFeCU%252Fsbv0kNiKY%253D\n" +
            "Connection: keep-alive\n" +
            "\n" +
            "action=login&username=10111957@free&password={B}MjM3MjQ5&ac_id=18&user_ip=&nas_ip=&user_mac=&ajax=1";

    public static void main(String[] args) {
        try{
            SocketChannel socketChannel=SocketChannel.open();
            socketChannel.connect(new InetSocketAddress("172.20.3.90",80));
            socketChannel.write(ByteBuffer.wrap(post.getBytes()));
            ByteBuffer buffer=ByteBuffer.allocate(1024);
            while(socketChannel.read(buffer)>0){
                buffer.flip();
                String content= Charset.forName("utf-8").decode(buffer).toString();
                System.out.println(content);
                buffer.clear();
            }
            socketChannel.close();
        }catch (IOException e){
            e.printStackTrace();
        }
    }
}

2. 要获得上述代码中post字符串，首先在windows电脑上安装一个fiddler，真的是非常好用。然后点击tools->options->connections，图中端口号可以自己设置，默认为8888，Allow remote computers to connect勾选上，点击确定就行了。

3. 在linux系统中，我使用的是centos7，点击网络设置，代理设置，在HTTP代理栏目里，IP为安装了fiddler的windows电脑的IP，可以在windows电脑上使用ipconfig查看，端口号就填写fiddler中设置的那个。

4. 在linux中打开浏览器，我使用的是firefox，然后输入账号密码，点击登录，在fiddler中便可以看到相应的请求信息，

左边为请求的URI，右边点击RAW，便可以得到我们第一步中的post字符串，即将此处框框里的所有内容都复制到代码中的post字符串就行了，然后将该java文件编译成class文件，再将该class文件传输到linux服务器中的某个目录下。

5. 假如该class文件名为Main.class，使用

java Main