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我创建了一个用于缓存来自服务器的用户图像的主HASHMAP回购。这个缓存是静态的。该缓存将用户ID保存为键和字节数组作为值。从字节数组创建位图时得到空值
private static HashMap<String, byte[]> sDrawables;
public static HashMap<String, byte[]> getMapInstance(){
if (sDrawables == null)
sDrawables = new HashMap<>();
return sDrawables;
}
我用的AsyncTask的从服务器下载图像,并把这个ID和图像阵列上HashMap和在此之后,我把这个地图我的主静的HashMap:
for (Map.Entry<String, byte[]> entry : drawables.entrySet()) {
ImgFactory.getMapInstance().put(entry.getKey(), entry.getValue());
}
在地方我想将此用户图像设置为我的图像视图,我将用户标识发送给主散列图,找到它后,我得到它的值,并将此值转换为位图。但其位不创建我的位图是空:
public static Drawable getConfigDrawable(Context context, String name) {
if (getMapInstance() != null && getMapInstance().containsKey(name)) {
Log.i("====>", "getConfigDrawable: "+ getMapInstance().containsKey(name));
byte[] arr = getMapInstance().get(name);
Bitmap bitmap = BitmapFactory.decodeByteArray(arr, 0, arr.length);
Log.i("===", "getConfigDrawable: " + bitmap.getHeight());
return new BitmapDrawable(context.getResources(), bitmap);
}
return null;
}
消息
java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getHeight()' on a null object reference
at safarayaneh.com.anotify.util.ImgFactory.getConfigDrawable(ImgFactory.java:72)
at safarayaneh.com.anotify.adapter.NotifyAdapter$1.onComplete(NotifyAdapter.java:201)
at safarayaneh.com.anotify.util.ImgFactory$1.onResult(ImgFactory.java:59)
at safarayaneh.com.anotify.tasks.GetImageTask.onPostExecute(GetImageTask.java:87)
at safarayaneh.com.anotify.tasks.GetImageTask.onPostExecute(GetImageTask.java:21)
at android.os.AsyncTask.finish(AsyncTask.java:651)
at android.os.AsyncTask.-wrap1(AsyncTask.java)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
我的日志:
anotify.debug I/====>: getConfigDrawable: true
Log.i("=====", "getConfigDrawable: length:"+ arr.length);
debug I/=====: getConfigDrawable: length: 12090
编辑
最后,这些代码是好的,我有一个位图。
byte[] tmp=new byte[result.getJSONArray("UserImage").length()];
for(int i=0;i<result.getJSONArray("UserImage").length();i++){
tmp[i]=(byte)(((int)result.getJSONArray("UserImage").get(i)) & 0xFF);
}
我把它转换成这样:http://codepad.org/i4KzzJzl这是我的回复json:http://codepad.org/XVVFM9ia –
因为我的json响应是字节:http://codepad.org/ XVVFM9ia –
好吧然后获取位图与尝试decodeStream()..,而不是decodeByteArray() –