第一步在手機中設置存儲sdcard權限
第二步AndroidManifest.xml
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
第三步:activity-main.xml
<SeekBar
android:id="@+id/seekbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:progress="50"/>
<ImageView
android:id="@+id/image"
android:layout_width="match_parent"
android:layout_height="150dp"
android:scaleType="center"/>
第四步MainActivity.Java
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.os.Bundle;
import android.util.Log;
import android.widget.ImageView;
import android.widget.SeekBar;
import androidx.appcompat.app.AppCompatActivity;
import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
public class MainActivity extends AppCompatActivity {
private SeekBar mSeekBar;
private final String urlString = "http://192.168.0.134:280/AA.jpg";
private ImageView mIV;
private int fileLength;
private Bitmap mBitmap;
public static void saveBitmap(Bitmap bitmap,String path) {
String savePath;
File filePic;
if (Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED)) {
savePath = path;
} else {
Log.e("tag", "saveBitmap failure : sdcard not mounted");
return;
}
try {
filePic = new File(savePath);
if (!filePic.exists()) {
filePic.getParentFile().mkdirs();
filePic.createNewFile();
}
FileOutputStream fos = new FileOutputStream(filePic);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
fos.flush();
fos.close();
} catch (IOException e) {
Log.e("tag", "saveBitmap: " + e.getMessage());
return;
}
Log.i("tag", "saveBitmap success: " + filePic.getAbsolutePath());
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSeekBar = (SeekBar)findViewById(R.id.seekbar);
mIV = (ImageView)findViewById(R.id.image);
new Thread(downloadRunn).start();
}
private Runnable downloadRunn = new Runnable(){
@Override
public void run() {
try {
String filepath="/sdcard/Download/xxxx20200601.jpg";
URL url = new URL(urlString);
URLConnection connection = url.openConnection();
connection.connect();
fileLength = connection.getContentLength();
InputStream in = new BufferedInputStream(connection.getInputStream());
byte[] arr = readStream(in);
mBitmap = BitmapFactory.decodeByteArray(arr,0,arr.length);
//測試保護文件函數代碼
saveBitmap(mBitmap,filepath);
//
connectHanlder.sendEmptyMessage(0);
} catch (Exception e) {
e.printStackTrace();
}
}
};
public byte[] readStream(InputStream in) throws Exception{
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte data[] = new byte[1024];
long total = 0;
int count;
while((count = in.read(data))!=-1){
total+=count;
mSeekBar.setProgress((int)(total*100)/fileLength);
bos.write(data,0,count);
}
bos.close();
in.close();
return bos.toByteArray();
}
private Handler connectHanlder = new Handler() {
@Override
public void handleMessage(Message msg) {
// 更新UI,顯示圖片
if (mBitmap != null) {
mIV.setImageBitmap(mBitmap);// display image
}
}
};
}
Android studio 網絡下載圖片並保存sdcard download 文件夾下
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