AsyncTask结合HttpUriconnection异步请求

package com.example.abnerming.httputil.net;

import android.os.AsyncTask;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

/**
 * 使用AyncTask来实现异步
 * */
public class HelperAsnc {
    public HelperAsnc(){}

    //get请求
    public HelperAsnc get(String url){
        doHttp(url,"GET","");
        return this;
    }

    //联网请求
    private void doHttp(String url,String method,String string){
        myAsyncTask=new MyAsyncTask(url,method,string);
        myAsyncTask.execute();
    }

    //post请求
    public HelperAsnc post(String url,String string){
        doHttp(url,"POST",string);
        return this;
    }

    private MyAsyncTask myAsyncTask;

    private class MyAsyncTask extends AsyncTask{
        private String url,method,string;
        public MyAsyncTask(String url,String method,String string){
            this.url=url;
            this.method=method;
            this.string=string;
        }
        //在子线程里运行
        @Override
        protected String doInBackground(String... strings) {
            String message="";
            try {
               URL mUrl=new URL(url);
               HttpURLConnection connection= (HttpURLConnection) mUrl.openConnection();
               connection.setRequestMethod(method);
               connection.setConnectTimeout(5000);

               if("POST".equals(method)){
                   PrintWriter printWriter=new PrintWriter(connection.getOutputStream());
                   printWriter.write(string);
                   printWriter.flush();
                   printWriter.close();
               }
               connection.connect();

               int code=connection.getResponseCode();
               if(code==HttpURLConnection.HTTP_OK){
                   InputStream inputStream=connection.getInputStream();
                   String data=convertStream2String(inputStream);
                   message=data;
               }else{
                   message="0";
               }
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return message;
        }

        //在主线程里设置方法
        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            if("0".equals(s)){//失败
                listener.fail();
            }else{
                listener.success(s);
            }

        }
    }

    //流转字符串
    private   String convertStream2String(InputStream input){
        ByteArrayOutputStream baos = new ByteArrayOutputStream();// 自带缓存的输出流
        int len=-1;
        byte [] buffer = new byte[512];
        try {
            while((len = input.read(buffer))!=-1){
                baos.write(buffer, 0, len); // 将读到的字节，写入baos
            }
            return new String(baos.toByteArray());
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    private HttpListener listener;

    //传递接口
    public void result(HttpListener listener){
        this.listener=listener;
    }

    public interface HttpListener{
        void success(String data);
        void fail();
    }
}