封装好的请求网络的接口

package com.example.ggq.xiaomi.activity.net;

import android.os.AsyncTask;
import android.text.TextUtils;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpUtils {
    private static final HttpUtils ourInstance = new HttpUtils();
    private String TAG = HttpUtils.class.getSimpleName();

    public static HttpUtils getInstance() {
        return ourInstance;
    }

    private HttpUtils() {
    }
    public void get(String url,NetCallback callback){
        new loadData(callback).execute(url);
    }

    private class loadData extends AsyncTask<String,Void,String> {
        private NetCallback callback;

        public loadData(NetCallback callback) {
            this.callback = callback;
        }

        @Override
        protected String doInBackground(String... strings) {
            try {
                URL url = new URL(strings[0]);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setReadTimeout(5000);
                connection.setConnectTimeout(5000);
                if(connection.getResponseCode() == HttpURLConnection.HTTP_OK){
                    return inputStream2String(connection.getInputStream());
                }
            } catch (Exception e) {
                e.printStackTrace();
                callback.onError(e.getMessage());
            }
            return null;
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            if(!TextUtils.isEmpty(s)){
                callback.onSuccess(s);
            }else {
                callback.onError("没有请求到数据!");
            }
        }
    }

    private String inputStream2String(InputStream inputStream) throws IOException {
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        int len = -1;
        byte[] bytes = new byte[1024];
        while ((len = inputStream.read(bytes)) != -1){
            outputStream.write(bytes,0,len);
        }
        return new String(outputStream.toByteArray());
    }

    public interface NetCallback {
        void onSuccess(String s);
        void onError(String errorMsg);
    }
}