Java 模拟器中InfiniteSrollAdapter中的URLImage显示NPE（CodenameOne）
我的应用程序有一个Java 模拟器中InfiniteSrollAdapter中的URLImage显示NPE（CodenameOne）,java,codenameone,Java,Codenameone,我的应用程序有一个InfiniteScrollAdapter，通过URLImage和URLImage.ImageAdapter填充图像 在模拟器（Iphone3GS或Xoom或GoogleNexus7）中，NPE在第一次出现InfiniteSrollAdapter时显示，尽管服务器上确实存在该文件 请注意：在这个测试中，数据库中只有一个条目。因此，在下面的图像上，您应该看到同一行（图像+文本）重复了3次。 请注意，未显示图标中的顺序可能不同 我用来下载图像的代码是： Image tempPl
InfiniteScrollAdapterURLImageURLImage.ImageAdapterInfiniteSrollAdapterImage tempPlaceholder = Image.createImage(
ParametresGeneraux.SIZE_OF_REPORT_PIC_IN_PX,
ParametresGeneraux.SIZE_OF_REPORT_PIC_IN_PX,
ParametresGeneraux.accentColor);
Graphics gr = tempPlaceholder.getGraphics();
gr.setAntiAliased(true);
gr.setColor(ParametresGeneraux.accentColor);
gr.fillArc(0, 0, ParametresGeneraux.SIZE_OF_REPORT_PIC_IN_PX, ParametresGeneraux.SIZE_OF_REPORT_PIC_IN_PX, 0, 360);
EncodedImage roundPlaceholder = EncodedImage.createFromImage(tempPlaceholder, true);
final Image reportImage = URLImage.createToStorage(
roundPlaceholder,
photoFilenameInStorage,
currentReport.getPhotoPath(),
ParametresGeneraux.RESIZE_SCALE_WITH_ROUND_MASK
);
public final static URLImage.ImageAdapter RESIZE_SCALE_WITH_ROUND_MASK = new URLImage.ImageAdapter() {
@Override
public EncodedImage adaptImage(EncodedImage downloadedImage, EncodedImage placeholderImage) {
final Image[] tmp = new Image[1];
if (!Display.getInstance().isEdt()) {
// The image scaling has to be called from EDT
Display.getInstance().callSeriallyAndWait(() -> {
tmp[0] = downloadedImage.scaledLargerRatio(placeholderImage.getWidth(), placeholderImage.getHeight());
if (tmp[0].getWidth() > placeholderImage.getWidth()) {
int diff = tmp[0].getWidth() - placeholderImage.getWidth();
int x = diff / 2;
tmp[0] = tmp[0].subImage(x, 0, placeholderImage.getWidth(), placeholderImage.getHeight(), true);
} else if (tmp[0].getHeight() > placeholderImage.getHeight()) {
int diff = tmp[0].getHeight() - placeholderImage.getHeight();
int y = diff / 2;
tmp[0] = tmp[0].subImage(0, y, Math.min(placeholderImage.getWidth(), tmp[0].getWidth()),
Math.min(placeholderImage.getHeight(), tmp[0].getHeight()), true);
}
});
} else {
tmp[0] = downloadedImage.scaledLargerRatio(placeholderImage.getWidth(), placeholderImage.getHeight());
if (tmp[0].getWidth() > placeholderImage.getWidth()) {
int diff = tmp[0].getWidth() - placeholderImage.getWidth();
int x = diff / 2;
tmp[0] = tmp[0].subImage(x, 0, placeholderImage.getWidth(), placeholderImage.getHeight(), true);
} else if (tmp[0].getHeight() > placeholderImage.getHeight()) {
int diff = tmp[0].getHeight() - placeholderImage.getHeight();
int y = diff / 2;
tmp[0] = tmp[0].subImage(0, y, Math.min(placeholderImage.getWidth(), tmp[0].getWidth()),
Math.min(placeholderImage.getHeight(), tmp[0].getHeight()), true);
}
}
EncodedImage[] image2Return = new EncodedImage[1];
if (!Display.getInstance().isEdt()) {
// The image scaling has to be called from EDT
Display.getInstance().callSeriallyAndWait(() -> {
Image roundMask = Image.createImage(tmp[0].getWidth(), tmp[0].getHeight(), 0xff000000);
Graphics gr = roundMask.getGraphics();
gr.setColor(0xffffff);
gr.fillArc(0, 0, tmp[0].getWidth(), tmp[0].getHeight(), 0, 360);
Object mask = roundMask.createMask();
tmp[0] = tmp[0].applyMask(mask);
image2Return[0] = EncodedImage.createFromImage(tmp[0], false);
});
} else {
Image roundMask = Image.createImage(tmp[0].getWidth(), tmp[0].getHeight(), 0xff000000);
Graphics gr = roundMask.getGraphics();
gr.setColor(0xffffff);
gr.fillArc(0, 0, tmp[0].getWidth(), tmp[0].getHeight(), 0, 360);
Object mask = roundMask.createMask();
tmp[0] = tmp[0].applyMask(mask);
image2Return[0] = EncodedImage.createFromImage(tmp[0], false);
}
return image2Return[0];
}
URLImage.ImageAdapterimageAdapter在适配器中检查
下载的image.getData（）null这是第二次，因为系统看到tmp文件，并假设下载正在进行，所以不会再次调用下载代码。tmp文件稍后将重命名为最终可下载文件。将ImageAdapter更改为以下内容：
public static final URLImage.ImageAdapter RESIZE_SCALE_WITH_ROUND_MASK = new URLImage.ImageAdapter() {
@Override
public EncodedImage adaptImage(EncodedImage downloadedImage, EncodedImage placeholderImage) {
Image tmp = downloadedImage.scaledLargerRatio(placeholderImage.getWidth(), placeholderImage.getHeight());
if (tmp.getWidth() > placeholderImage.getWidth()) {
int diff = tmp.getWidth() - placeholderImage.getWidth();
int x = diff / 2;
tmp = tmp.subImage(x, 0, placeholderImage.getWidth(), placeholderImage.getHeight(), true);
} else if (tmp.getHeight() > placeholderImage.getHeight()) {
int diff = tmp.getHeight() - placeholderImage.getHeight();
int y = diff / 2;
tmp = tmp.subImage(0, y, Math.min(placeholderImage.getWidth(), tmp.getWidth()),
Math.min(placeholderImage.getHeight(), tmp.getHeight()), true);
}
Image roundMask = Image.createImage(tmp.getWidth(), tmp.getHeight(), 0xff000000);
Graphics gr = roundMask.getGraphics();
gr.setColor(0xffffff);
gr.fillArc(0, 0, tmp.getWidth(), tmp.getHeight(), 0, 360);
Object mask = roundMask.createMask();
tmp = tmp.applyMask(mask);
return EncodedImage.createFromImage(tmp, false);
}
@Override
public boolean isAsyncAdapter() {
return true;
}
};
EDTtempPlaceholdercallSerially（）方法中调用URLImage
：
Image tempPlaceholder = Image.createImage(
ParametresGeneraux.SIZE_OF_REPORT_PIC_IN_PX,
ParametresGeneraux.SIZE_OF_REPORT_PIC_IN_PX,
ParametresGeneraux.accentColor);
Graphics gr = tempPlaceholder.getGraphics();
gr.setAntiAliased(true);
gr.setColor(ParametresGeneraux.accentColor);
gr.fillArc(0, 0, ParametresGeneraux.SIZE_OF_REPORT_PIC_IN_PX, ParametresGeneraux.SIZE_OF_REPORT_PIC_IN_PX, 0, 360);
myComponent.setIcon(tempPlaceholder);
...
//Then call this at the end of everything
Display.getInstance().callSerially(() -> {
EncodedImage roundPlaceholder = EncodedImage.createFromImage(tempPlaceholder, true);
final Image reportImage = URLImage.createToStorage(
roundPlaceholder,
photoFilenameInStorage,
currentReport.getPhotoPath(),
ParametresGeneraux.RESIZE_SCALE_WITH_ROUND_MASK
);
myComponent.setIcon(reportImage);
myComponent.getComponentForm().repaint();
});
编辑：
根据@Shai的回答，您可以检查您当前是否处于停机状态
//Declare this at the top of your class
final static private Map<String, Image> LOADED_URLS = new HashMap<>();
//Then change the URLImage image method to this
Display.getInstance().callSerially(() -> {
EncodedImage roundPlaceholder = EncodedImage.createFromImage(tempPlaceholder, true);
final Image reportImage = LOADED_URLS.containsKey(photoFilenameInStorage) ? LOADED_URLS.get(photoFilenameInStorage)
: URLImage.createToStorage(
roundPlaceholder,
photoFilenameInStorage,
currentReport.getPhotoPath(),
ParametresGeneraux.RESIZE_SCALE_WITH_ROUND_MASK
);
LOADED_URLS.put(photoFilenameInStorage, reportImage);
myComponent.setIcon(reportImage);
myComponent.getComponentForm().repaint();
});