Android 使用URL下载图片到本地并显示

秒速五厘米 2022-07-15 19:45 403阅读 0赞

package com.example.kirito.myapplication.testhttp;
    
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.os.Environment;
    import android.os.Handler;
    import android.util.Log;
    import android.widget.ImageView;
    
    import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStreamWriter;
    import java.net.HttpURLConnection;
    import java.net.MalformedURLException;
    import java.net.URL;
    import java.util.Calendar;
    
    /**
     * Created by kirito on 2016.10.24.
     */
    
    public class HttpImgThread extends Thread {
        private Handler handler;
        private ImageView iv;
        private String strurl;
    
        private static final String TAG = "HttpImgThread";
    
        public HttpImgThread (Handler handler,ImageView iv,String strurl){
            this.handler = handler;
            this.iv = iv;
            this.strurl = strurl;
        }
    
        @Override
        public void run() {
            URL url = null;
            HttpURLConnection con = null;
            try {
                url = new URL(strurl);
                con = (HttpURLConnection) url.openConnection();
                con.setRequestMethod("GET");
                con.setReadTimeout(5000);
                con.setDoInput(true);
                //InputStream in = con.getInputStream();
                File parent = Environment.getExternalStorageDirectory();
                File file = new File(parent,String.valueOf(System.currentTimeMillis()));
                FileOutputStream fos = new FileOutputStream(file);
                InputStream in = con.getInputStream();
                Log.e(TAG, "run: path---"+file.getAbsolutePath() );
    
                byte ch[] = new byte[2 * 1024];
                int len;
                if (fos != null){
                    while ((len = in.read(ch)) != -1){
                        fos.write(ch,0,len);
                    }
                    in.close();
                    fos.close();
                }
                /*BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));
                BufferedWriter bw = null;
                String s;
                while ((s = br.readLine()) != null){
                    bw = new BufferedWriter(new OutputStreamWriter(fos));
                    //以字符串的形式写入数据，无法读取图片
                    bw.write(s);
                }
                br.close();
                bw.close();*/
                final Bitmap bitmap = BitmapFactory.decodeFile(file.getAbsolutePath());
                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        if (bitmap != null){
                            iv.setImageBitmap(bitmap);
                        }
                    }
                });
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }