我正在创建一个应用程序，我可以将图像上传到服务器，但我在这些代码行中遇到问题。它会产生 OutOfMemmoryError ，如下所示。
package com.technow.pereo;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.io.IOUtils;
import android.content.Context;
import android.graphics.Bitmap;
import android.net.Uri;
import android.util.Log;
public class FileHelper {
public static final String TAG = FileHelper.class.getSimpleName();
public static final int SHORT_SIDE_TARGET = 1280;
public static byte[] getByteArrayFromFile(Context context, Uri uri) {
byte[] fileBytes = null;
InputStream inStream = null;
ByteArrayOutputStream outStream = null;
if (uri.getScheme().equals("content")) {
try {
inStream = context.getContentResolver().openInputStream(uri);
outStream = new ByteArrayOutputStream();
byte[] bytesFromFile = new byte[1024 * 1024]; // buffer size (1
// MB)
int bytesRead = inStream.read(bytesFromFile);
while (bytesRead != -1) {
outStream.write(bytesFromFile, 0, bytesRead);
bytesRead = inStream.read(bytesFromFile);
}
fileBytes = outStream.toByteArray();
} catch (IOException e) {
Log.e(TAG, e.getMessage());
} finally {
try {
inStream.close();
outStream.close();
} catch (IOException e) { /* ( Intentionally blank */
}
}
} else {
try {
File file = new File(uri.getPath());
FileInputStream fileInput = new FileInputStream(file);
fileBytes = IOUtils.toByteArray(fileInput);
} catch (IOException e) {
Log.e(TAG, e.getMessage());
}
}
return fileBytes;
}
public static byte[] reduceImageForUpload(byte[] imageData) {
Bitmap bitmap = null ;
bitmap = ImageResizer.resizeImageMaintainAspectRatio(imageData,
SHORT_SIDE_TARGET);
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 50, outputStream);
bitmap.recycle();
bitmap = null;
byte[] reducedData = outputStream.toByteArray();
try {
outputStream.close();
} catch (IOException e) {
// Intentionally blank
}
return reducedData;
}
public static String getFileName(Context context, Uri uri, String fileType) {
String fileName = "uploaded_file.";
if (fileType.equals(ParseConstants.TYPE_IMAGE)) {
fileName += "png";
} else {
// For video, we want to get the actual file extension
if (uri.getScheme().equals("content")) {
// do it using the mime type
String mimeType = context.getContentResolver().getType(uri);
int slashIndex = mimeType.indexOf("/");
String fileExtension = mimeType.substring(slashIndex + 1);
fileName += fileExtension;
} else {
fileName = uri.getLastPathSegment();
}
}
return fileName;
}
和ImageResizer.class
package com.technow.pereo;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Pair;
public class ImageResizer {
/*
* Call this static method to resize an image to a specified width and height.
*
* @param targetWidth The width to resize to.
* @param targetHeight The height to resize to.
* @returns The resized image as a Bitmap.
*/
public static Bitmap resizeImage(byte[] imageData, int targetWidth, int targetHeight) {
// Use BitmapFactory to decode the image
BitmapFactory.Options options = new BitmapFactory.Options();
// inSampleSize is used to sample smaller versions of the image
options.inSampleSize = calculateInSampleSize(options, targetWidth, targetHeight);
// Decode bitmap with inSampleSize and target dimensions set
options.inJustDecodeBounds = false;
Bitmap reducedBitmap = BitmapFactory.decodeByteArray(imageData, 0, imageData.length, options);
Bitmap resizedBitmap = Bitmap.createScaledBitmap(reducedBitmap, targetWidth, targetHeight, false);
return resizedBitmap;
}
public static Bitmap resizeImageMaintainAspectRatio(byte[] imageData, int shorterSideTarget) {
Pair<Integer, Integer> dimensions = getDimensions(imageData);
// Determine the aspect ratio (width/height) of the image
int imageWidth = dimensions.first;
int imageHeight = dimensions.second;
float ratio = (float) dimensions.first / dimensions.second;
int targetWidth;
int targetHeight;
// Determine portrait or landscape
if (imageWidth > imageHeight) {
// Landscape image. ratio (width/height) is > 1
targetHeight = shorterSideTarget;
targetWidth = Math.round(shorterSideTarget * ratio);
}
else {
// Portrait image. ratio (width/height) is < 1
targetWidth = shorterSideTarget;
targetHeight = Math.round(shorterSideTarget / ratio);
}
return resizeImage(imageData, targetWidth, targetHeight);
}
public static Pair<Integer, Integer> getDimensions(byte[] imageData) {
// Use BitmapFactory to decode the image
BitmapFactory.Options options = new BitmapFactory.Options();
// Only decode the bounds of the image, not the whole image, to get the dimensions
options.inJustDecodeBounds = true;
BitmapFactory.decodeByteArray(imageData, 0, imageData.length, options);
return new Pair<Integer, Integer>(options.outWidth, options.outHeight);
}
public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) > reqHeight
&& (halfWidth / inSampleSize) > reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
}
代码运行时没有错误，但随后抛出OutOfMemmoryException。 我捕获此异常，它最终发送图像，但为什么我收到此错误。这会减慢上传时间。 以下是我在LogCat中获得的详细信息：
06-30 15:59:11.293: W/System.err(9114): java.lang.OutOfMemoryError
06-30 15:59:11.293: W/System.err(9114): at android.graphics.Bitmap.nativeCreate(Native Method)
06-30 15:59:11.293: W/System.err(9114): at android.graphics.Bitmap.createBitmap(Bitmap.java:809)
06-30 15:59:11.294: W/System.err(9114): at android.graphics.Bitmap.createBitmap(Bitmap.java:786)
06-30 15:59:11.294: W/System.err(9114): at android.graphics.Bitmap.createBitmap(Bitmap.java:718)
06-30 15:59:11.294: W/System.err(9114): at android.graphics.Bitmap.createScaledBitmap(Bitmap.java:594)
06-30 15:59:11.294: W/System.err(9114): at com.technow.pereo.ImageResizer.resizeImage(ImageResizer.java:27)
06-30 15:59:11.294: W/System.err(9114): at com.technow.pereo.ImageResizer.resizeImageMaintainAspectRatio(ImageResizer.java:55)
06-30 15:59:11.294: W/System.err(9114): at com.technow.pereo.FileHelper.reduceImageForUpload(FileHelper.java:65)
06-30 15:59:11.294: W/System.err(9114): at com.technow.pereo.RecipientsActivity.createMessage(RecipientsActivity.java:240)
06-30 15:59:11.300: W/System.err(9114): at com.technow.pereo.RecipientsActivity$2$1.run(RecipientsActivity.java:96)
06-30 15:59:11.303: W/System.err(9114): at java.lang.Thread.run(Thread.java:841)
请嗨我！
答案 0 :(得分：1)
设置要上传到服务器的目标大小或分辨率，并仅使用inSampleSize属性加载基于该目标的图像。
我还建议您以连续方式进行上传而不是并行，这样一次只有一张图像可以在内存中上传。
注意：在您的reduceImageForUpload()中，您应该使用inSampleSize而不是解码图像，然后再回收它。