class ImageActivity

package com.example.choi.ex05_network;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class ImageActivity extends AppCompatActivity implements Runnable{

    //1. 변수 선언
    Button button1;
    ImageView img1;
    Bitmap bitmap; //비트맵 객체

    final String img_url ="http://192.168.0.2:2424/mainbanner/78ef8348-fbd4-486c-8b95-71a246bad6b3_1.jpg";

    //메인 스레드와 백그라운드 스레드 간의 통신
    Handler handler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            //이미지뷰에 비트맵 리소스 연결
            img1.setImageBitmap(bitmap);
        }
    };



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.image);

        //2. 위젯 연결
        button1=(Button)findViewById(R.id.button1);
        img1=(ImageView)findViewById(R.id.img1);

        //3. 버튼 클릭 이벤트
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //백그라운드 스레드 생성
                Thread th=new Thread(ImageActivity.this);
                th.start(); //run() 이 실행됨.

            }
        });
    }

    //Alt + Insert Implement methods
    @Override
    public void run() {
    //http://192.168.0.2:2424/mainbanner/78ef8348-fbd4-486c-8b95-71a246bad6b3_1.jpg

        URL url=null;
        try{
            //스트링 주소를 url 형식으로 변환
            url=new URL(img_url);
            //url 에 접속 시도
            HttpURLConnection connection=(HttpURLConnection)url.openConnection();

            connection.connect();
            //스트림 생성
            InputStream is=connection.getInputStream();
            //스트림에서 받은 데이터를 비트맵 변환
            bitmap= BitmapFactory.decodeStream(is);

            // 핸들러에게 화면 갱시 요청
            handler.sendEmptyMessage(0);

            //연결 종료
            connection.disconnect();
        }catch (Exception e){
            e.printStackTrace();
        }
    }





}

 

 

image

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/image"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.choi.ex05_network.ImageActivity">

    <Button
        android:text="다운로드"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true"
        android:id="@+id/button1" />

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:srcCompat="@mipmap/ic_launcher"
        android:layout_below="@+id/button1"
        android:layout_marginTop="18dp"
        android:id="@+id/img1"
        android:layout_alignParentEnd="true" />
</RelativeLayout>