将url从网址保存到sdcard
我将图片从网址保存到sdcard。但在SD卡中图像大小为0。图像是在SD卡中创建的,但现在从url中检索数据并保存。所以它给我的尺寸。将url从网址保存到sdcard
try
{
URL url = new URL("http://api.androidhive.info/images/sample.jpg");
InputStream input = url.openStream();
try {
//The sdcard directory e.g. '/sdcard' can be used directly, or
//more safely abstracted with getExternalStorageDirectory()
File storagePath = Environment.getExternalStorageDirectory();
OutputStream output = new FileOutputStream (new File(storagePath,username+".png"));
try {
byte[] buffer = new byte[2048];
int bytesRead = 0;
while ((bytesRead = input.read(buffer, 0, buffer.length)) >= 0) {
output.write(buffer, 0, bytesRead);
}
} finally {
output.close();
}
} finally {
input.close();
}
} catch(Exception e)
{
System.out.println("error in sd card "+e.toString());
}
试试这个code.It工程...
你应该有互联网的权限和写入外部存储。
try
{
URL url = new URL("Enter the URL to be downloaded");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
urlConnection.connect();
File SDCardRoot = Environment.getExternalStorageDirectory().getAbsoluteFile();
String filename="downloadedFile.png";
Log.i("Local filename:",""+filename);
File file = new File(SDCardRoot,filename);
if(file.createNewFile())
{
file.createNewFile();
}
FileOutputStream fileOutput = new FileOutputStream(file);
InputStream inputStream = urlConnection.getInputStream();
int totalSize = urlConnection.getContentLength();
int downloadedSize = 0;
byte[] buffer = new byte[1024];
int bufferLength = 0;
while ((bufferLength = inputStream.read(buffer)) > 0)
{
fileOutput.write(buffer, 0, bufferLength);
downloadedSize += bufferLength;
Log.i("Progress:","downloadedSize:"+downloadedSize+"totalSize:"+ totalSize) ;
}
fileOutput.close();
if(downloadedSize==totalSize) filepath=file.getPath();
}
catch (MalformedURLException e)
{
e.printStackTrace();
}
catch (IOException e)
{
filepath=null;
e.printStackTrace();
}
Log.i("filepath:"," "+filepath) ;
return filepath;
我试过并得到totalSize = -1 – user2160008 2013-05-07 08:30:36
我测试模拟器 – user2160008 2013-05-07 08:31:03
检查设备 – 2013-05-07 10:32:41
试试这个,这可能会晚,但它会帮助别人。
private class ImageDownloadAndSave extends AsyncTask<String, Void, Bitmap>
{
@Override
protected Bitmap doInBackground(String... arg0)
{
downloadImagesToSdCard("","");
return null;
}
private void downloadImagesToSdCard(String downloadUrl,String imageName)
{
try
{
URL url = new URL(img_URL);
/* making a directory in sdcard */
String sdCard=Environment.getExternalStorageDirectory().toString();
File myDir = new File(sdCard,"test.jpg");
/* if specified not exist create new */
if(!myDir.exists())
{
myDir.mkdir();
Log.v("", "inside mkdir");
}
/* checks the file and if it already exist delete */
String fname = imageName;
File file = new File (myDir, fname);
if (file.exists())
file.delete();
/* Open a connection */
URLConnection ucon = url.openConnection();
InputStream inputStream = null;
HttpURLConnection httpConn = (HttpURLConnection)ucon;
httpConn.setRequestMethod("GET");
httpConn.connect();
if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK)
{
inputStream = httpConn.getInputStream();
}
FileOutputStream fos = new FileOutputStream(file);
int totalSize = httpConn.getContentLength();
int downloadedSize = 0;
byte[] buffer = new byte[1024];
int bufferLength = 0;
while ((bufferLength = inputStream.read(buffer)) >0)
{
fos.write(buffer, 0, bufferLength);
downloadedSize += bufferLength;
Log.i("Progress:","downloadedSize:"+downloadedSize+"totalSize:"+ totalSize) ;
}
fos.close();
Log.d("test", "Image Saved in sdcard..");
}
catch(IOException io)
{
io.printStackTrace();
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
在AsyncTask中声明您的网络操作,因为它会将其加载为后台任务。不要在主线程上加载网络操作。在这之后无论是在按一下按钮或内容视图调用这个类像
new ImageDownloadAndSave().execute("");
而且不要忘记添加联播网,权限为:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.INTERNET" />
希望这将有助于:-)
你应该有互联网许可和写入外部存储。 – 2013-05-07 08:28:29