在我的应用程序中，我将图像上传到服务器（使用以下代码）我可以成功地将图像上传到服务器。我的问题是，如果我上传一张我用相机拍摄的图像，由于图像的大小（1.5 - 5 MB），上传图片需要很长时间。我在android中看到了很多压缩方法，但是我无法找到我应该在我的代码中使用哪个，因为我是android的新手。我想减少上传所需的时间。任何人都可以告诉我如何压缩图像并上传到服务器？
public int uploadFile(String sourceFileUri) {
String fileName = sourceFileUri;
HttpURLConnection conn = null;
DataOutputStream dos = null;
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1 * 1024 * 1024;
File sourceFile = new File(sourceFileUri);
if (!sourceFile.isFile()) {
//dialog.dismiss();
Log.e("uploadFile", "Source File not exist :"+imagepath);
runOnUiThread(new Runnable() {
public void run() {
messageText.setText("Source File not exist :"+ imagepath);
}
});
return 0;
}
else
{
try {
// open a URL connection to the Servlet
FileInputStream fileInputStream = new FileInputStream(sourceFile);
URL url = new URL(upLoadServerUri);
// Open a HTTP connection to the URL
conn = (HttpURLConnection) url.openConnection();
conn.setDoInput(true); // Allow Inputs
conn.setDoOutput(true); // Allow Outputs
conn.setUseCaches(false); // Don't use a Cached Copy
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("ENCTYPE", "multipart/form-data");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
conn.setRequestProperty("uploaded_file", fileName);
dos = new DataOutputStream(conn.getOutputStream());
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""
+ fileName + "\"" + lineEnd);
dos.writeBytes(lineEnd);
// create a buffer of maximum size
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
// read file and write it into form...
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0) {
//dos.write(buffer, 0, bufferSize);
dos.write(buffer, 0, bytesRead);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
// send multipart form data necesssary after file data...
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
// Responses from the server (code and message)
serverResponseCode = conn.getResponseCode();
String serverResponseMessage = conn.getResponseMessage();
Log.i("uploadFile", "HTTP Response is : "
+ serverResponseMessage + ": " + serverResponseCode);
if(serverResponseCode == 200){
runOnUiThread(new Runnable() {
public void run() {
//String msg = "File Upload Completed.";
//messageText.setText("File Upload Completed.");
// Toast.makeText(Messaging.this, "Image Sent Successfully", Toast.LENGTH_SHORT).show();
dialog.dismiss();
Toast toast = Toast.makeText(Messaging.this, "Image Successfully Shuffled and Sent \n You will be notified once it is solved", Toast.LENGTH_SHORT);
toast.setGravity(Gravity.CENTER|Gravity.CENTER, 0, 60);
toast.setDuration(Toast.LENGTH_LONG);
toast.show();
}
});
}
//close the streams //
fileInputStream.close();
dos.flush();
dos.close();
} catch (MalformedURLException ex) {
//dialog.dismiss();
ex.printStackTrace();
runOnUiThread(new Runnable() {
public void run() {
messageText.setText("MalformedURLException Exception : check script url.");
Toast.makeText(Messaging.this, "MalformedURLException", Toast.LENGTH_SHORT).show();
}
});
Log.e("Upload file to server", "error: " + ex.getMessage(), ex);
} catch (Exception e) {
//dialog.dismiss();
e.printStackTrace();
runOnUiThread(new Runnable() {
public void run() {
messageText.setText("Got Exception : see logcat ");
Toast.makeText(Messaging.this, "Got Exception : see logcat ", Toast.LENGTH_SHORT).show();
}
});
Log.e("Upload file to server Exception", "Exception : " + e.getMessage(), e);
}
return serverResponseCode;
}
}
先谢谢
答案 0 :(得分：0)
为旧图像创建新的图像位图，您需要调整图像像素的大小，以便获得小尺寸图像
此代码可以调整位图大小，以便您可以将位图转换为图像
public Bitmap getBitmapFromFile(File dst) {
if (null != dst && dst.exists()) {
BitmapFactory.Options opts = null;
opts = new BitmapFactory.Options();
opts.inJustDecodeBounds = true;
BitmapFactory.decodeFile(dst.getPath(), opts);
// calculate image size
int width;
int height;
if (opts.outHeight > opts.outWidth) {
height = 80;
width = 50;
}
else {
height = 60;
width = 80;
}
final int minSideLength = Math.min(width, height);
opts.inSampleSize = computeSampleSize(opts, minSideLength,
width * height);
opts.inJustDecodeBounds = false;
opts.inInputShareable = true;
opts.inPurgeable = true;
try {
return BitmapFactory.decodeFile(dst.getPath(), opts);
} catch (OutOfMemoryError e) {
e.printStackTrace();
}
}
return null;
}
public static int computeSampleSize(BitmapFactory.Options options,
int minSideLength, int maxNumOfPixels) {
int initialSize = computeInitialSampleSize(options, minSideLength,
maxNumOfPixels);
int roundedSize;
if (initialSize <= 8) {
roundedSize = 1;
while (roundedSize < initialSize) {
roundedSize <<= 1;
}
} else {
roundedSize = (initialSize + 7) / 8 * 8;
}
return roundedSize;
}
private static int computeInitialSampleSize(BitmapFactory.Options options,
int minSideLength, int maxNumOfPixels) {
double w = options.outWidth;
double h = options.outHeight;
int lowerBound = (maxNumOfPixels == -1) ? 1 :
(int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));
int upperBound = (minSideLength == -1) ? 128 :
(int) Math.min(Math.floor(w / minSideLength),
Math.floor(h / minSideLength));
if (upperBound < lowerBound) {
return lowerBound;
}
if ((maxNumOfPixels == -1) &&
(minSideLength == -1)) {
return 1;
} else if (minSideLength == -1) {
return lowerBound;
} else {
return upperBound;
}
}
将文件转换为位图后，您可以将此tutorial转换位图转换为文件
答案 1 :(得分：0)
尝试此调整大小片段，参数samplingSize是您想要的图像的像素（宽度*高度）。
public static Bitmap getSamplingImage(Bitmap sourceBitmap, int samplingSize) {
Bitmap outputBitmap = null;
int width = sourceBitmap.getWidth();
int height = sourceBitmap.getHeight();
int newWidth = width;
int newHeight = height;
if (newWidth * newHeight > samplingSize) {
while (true) {
if (newWidth * newHeight < samplingSize)
break;
newWidth /= 2;
newHeight /= 2;
}
}
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
outputBitmap = Bitmap.createBitmap(sourceBitmap, 0, 0, width, height, matrix, true);
return outputBitmap;
}