import java.io.*;
import java.net.Socket;

public class HTTPUtil {
    private String getReq = "";
    private String postReq = "";
    private String host = "";
    private String port = "80";

    //从请求中解析host和默认端口号
    protected void praseHost(String arg) {
            if (arg.indexOf(":") == arg.lastIndexOf(":")) {
                host = arg.toLowerCase().replace("host:", "")
                        .trim();
            } else {
                host = arg.toLowerCase().replace("host:", "")
                        .trim().split(":")[0];
                port = arg.toLowerCase().replace("host:", "")
                        .trim().split(":")[1];
            }
    }

    public void setRequest(String req) {
        if (req.toLowerCase().startsWith("get")) {
            setGetRequest(req);
        } else {
            setPostRequest(req);
        }
    }


    //设置GET请求原文
    protected void setGetRequest(String req) {
        String[] args = req.split("\n");
        for(String arg: args) {
            getReq += arg + "\r\n";
            if (arg.startsWith("Host")) {
                praseHost(arg);
            }
        }
        getReq += "\r\n";
    }

    //设置POST请求原文
    protected void setPostRequest(String req) {
        String postFlag = "$POST_CRLF$";
        req = req.replace("\n\n",postFlag);
        String[] args = req.split("\n");
        for(String arg: args) {
            postReq += arg + "\r\n";
            if (arg.toLowerCase().startsWith("host")) {
                praseHost(arg);
            }
        }
        postReq = postReq.replace(postFlag,"\r\n\r\n");
        postReq += "\r\n";
    }

    //发送请求并打印结果
    public String getResponse() {
        String res = "";
        try {
            Socket s = new Socket(host,Integer.valueOf(port));
            BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
            BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
            if (getReq.isEmpty()) {
                bw.write(postReq);
                postReq = "";//置空
            } else {
                bw.write(getReq);
                getReq = "";//置空
            }
            bw.flush();
            String line = null;
            while ((line = br.readLine()) != null) {
                res += line + "\n";
            }
            bw.close();
            br.close();
            System.out.println("[+] Done.");
        } catch (IOException e) {
            e.printStackTrace();
        }

        return res;
    }
}