package com.lidaochen.test;

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.util.Base64;

import android.view.View;

import android.widget.EditText;

import android.widget.ImageView;

import android.widget.Toast;

import java.io.File;

import java.io.FileOutputStream;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URL;

public class MainActivity extends AppCompatActivity {

    private EditText et_path;

    private ImageView iv_pic;

    // 创建handler对象

    public Handler handler = new Handler()

    {

        @Override

        public void handleMessage(Message msg) {

            super.handleMessage(msg);

            Bitmap bitmap = (Bitmap)msg.obj;

            // 设置图片到ImageView

            iv_pic.setImageBitmap(bitmap);

        }

    };

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        // 找到  ImageView 和 EditText控件

        et_path = (EditText)findViewById(R.id.et_path);

        iv_pic = (ImageView)findViewById(R.id.iv_pic);

    }

    public void click(View v)

    {

        new Thread()

        {

            public void run()

            {

                try

                {

                    // 获取图片路径

                    String path = et_path.getText().toString().trim();

                    File file = new File(getCacheDir(), Base64.encodeToString(path.getBytes(), Base64.DEFAULT));

                    if (file.exists() && file.length() > 0)

                    {

                        // 使用缓存图片

                        System.out.println("使用缓存图片！");

                        final Bitmap cacheBitmap = BitmapFactory.decodeFile(file.getAbsolutePath());

                        // 把cacheBitmap显示到ImageView上

                        Message msg = Message.obtain(); // 使用Message的静态方法，可以减少对象的创建

                        msg.obj = cacheBitmap;

                        handler.sendMessage(msg);

                    }

                    else

                    {

                        // Toast.makeText(getApplicationContext(), "第一次连接网络！", Toast.LENGTH_SHORT).show();

                        System.out.println("第一次连接网络！");

                        // 创建url对象

                        URL url = new URL(path);

                        //  获取HttpURLConnection对象

                        HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();

                        // 设置请求方式

                        httpURLConnection.setRequestMethod("GET");

                        // 设置超时时间

                        httpURLConnection.setReadTimeout(5000);

                        // 获取服务器返回的状态码

                        int code = httpURLConnection.getResponseCode();

                        if (code == 200)

                        {

                            // 获取图片数据，不管什么数据，都是以流的形式返回

                            InputStream in = httpURLConnection.getInputStream();

                            // 缓存图片 谷歌给我们提供了一个缓存目录

                            FileOutputStream fos = new FileOutputStream(file);

                            int len = -1;

                            byte buffer[] = new byte[1024]; // 1kB

                            while((len = in.read(buffer)) != -1)

                            {

                                fos.write(buffer, 0, len);

                            }

                            // 关闭流

                            fos.close();

                            in.close();

                            // 通过位图工厂，获取位图

                            final Bitmap bitmap = BitmapFactory.decodeFile(file.getAbsolutePath());

                            // 创建MSG 对象

                            // Message msg = new Message();

                            Message msg = Message.obtain(); // 使用Message的静态方法，可以减少对象的创建

                            msg.obj = bitmap;

                            handler.sendMessage(msg);

                        }

                    }

                }

                catch (Exception e)

                {

                    e.printStackTrace();

                }

            }

        }.start();

    }

}