难道我学了Http请求？（多图）

什么是Http请求？嗯？快说

使用HttpURLConnection发送网络请求

答非所问

我知道，我还知道你要问我什么是HttpurlConnection呢

你说

使用HttpURLConnection下载网络资源。下载网络资源用到的知识点，除了网络资源访问，还需要用到文件操作的知识，比如判断文件是否存在、创建目录、创建文件等等。
怎么使用？？

package com.example.lenovo.handlerdemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class Main2Activity extends AppCompatActivity {
    private Button getwebBtn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        bindID();
        getwebBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        getWebInfo();
                    }
                });
            }
        });

    }

    private void getWebInfo() {
        try {
                URL url = new URL("http://csdn.com/");
                HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                InputStream inputStream = httpURLConnection.getInputStream();
                InputStreamReader reader = new InputStreamReader(inputStream,"UTF-8");
                BufferedReader bufferedReader = new StringBuffer(reader);
                StringBuffer stringBuffer = new StringBuffer();
                String temp=null;

                while ((temp=bufferedReader.readLine())!=null){
                    stringBuffer.append(temp);

                }
                bufferedReader.close();
                reader.close();
                inputStream.close();
            Log.e("MAIN",stringBuffer.toString());



        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void bindID() {
        getwebBtn = findViewById(R.id.getweb_btn);
    }
}