排球图像加载器ConcurrentModificationException [英] Volley Image Loader ConcurrentModificationException
本文介绍了排球图像加载器ConcurrentModificationException的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在使用Volley Image loader从服务器将图像加载到我的项目中.但是在某些情况下，我会收到以下错误，并且应用程序崩溃.
I am using volley image loader for loading image on my project from server. But in some cases i am getting the following error and application crashes.
java.util.ConcurrentModificationException
at java.util.LinkedList$LinkIterator.next(LinkedList.java:124)
at com.android.volley.toolbox.ImageLoader$4.run(ImageLoader.java:440)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5343)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)
我找不到错误的原因和解决方案.请帮助我.
I can't find reason for the error and the solution for this. Please help me.
Global.java
Global.java
import android.app.Application;
import android.text.TextUtils;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.Volley;
import com.example.volley.LruBitmapCache;
import java.util.HashMap;
public class Global extends Application{
public static final String TAG = Global.class.getSimpleName();
private RequestQueue mRequestQueue;
private ImageLoader mImageLoader;
private static Global mInstance;
@Override
public void onCreate() {
super.onCreate();
mInstance = this;
}
public static synchronized Global getInstance() {
return mInstance;
}
public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
mRequestQueue = Volley.newRequestQueue(getApplicationContext());
}
return mRequestQueue;
}
public ImageLoader getImageLoader() {
getRequestQueue();
if (mImageLoader == null) {
mImageLoader = new ImageLoader(this.mRequestQueue,new LruBitmapCache());
}
return this.mImageLoader;
}
public <T> void addToRequestQueue(Request<T> req, String tag) {
req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
getRequestQueue().add(req);
}
public void cancelPendingRequests(Object tag) {
if (mRequestQueue != null) {
mRequestQueue.cancelAll(tag);
}
}
}
LruBitmapCache.java
LruBitmapCache.java
import com.android.volley.toolbox.ImageLoader.ImageCache;
import android.graphics.Bitmap;
import android.support.v4.util.LruCache;
public class LruBitmapCache extends LruCache<String, Bitmap> implements ImageCache {
public static int getDefaultLruCacheSize() {
final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
final int cacheSize = maxMemory / 8;
return cacheSize;
}
public LruBitmapCache() {
this(getDefaultLruCacheSize());
}
public LruBitmapCache(int sizeInKiloBytes) {
super(sizeInKiloBytes);
}
@Override
protected int sizeOf(String key, Bitmap value) {
return value.getRowBytes() * value.getHeight() / 1024;
}
@Override
public Bitmap getBitmap(String url) {
return get(url);
}
@Override
public void putBitmap(String url, Bitmap bitmap) {
put(url, bitmap);
}
}
将图片加载到网络视图中的代码
Code to loading image into network view
ImageLoader myLoader = Global.getInstance().getImageLoader();
networkImageView.setImageUrl(thumbnailURL, myLoader);
myLoader.get(thumbnailURL, new ImageLoader.ImageListener() {
@Override
public void onErrorResponse(VolleyError error) {
//Set Error image
}
@Override
public void onResponse(ImageLoader.ImageContainer response, boolean isImmediate) {
if (response.getBitmap() != null) {
//Set BitMap
}
else{
//Set Loading image
}
}
});
我的服装网络视图图像视图侦听器
My Costume network view image view listener
public class NetworkImageViewListener {
private final String TAG_THUMBNAIL_ERROR = "THUMBNAIL_ERROR";
private final String TAG_THUMBNAIL_RECEIVED = "THUMBNAIL_RECEIVED";
private String TAG = getClass().getSimpleName();
private boolean original_image_loaded = false;
public void loadImage(final Context context,final String url,final NetworkImageView networkImageView, final int approx_width, final int approx_height,final boolean thumbnail, final ProgressBar progressBar, final boolean is_Store){
networkImageView.setAdjustViewBounds(true);
final int picture_not_found = R.drawable.ic_profile_picture_not_found;
final int picture_not_loaded = R.drawable.ic_profile_picture_not_loaded;
if (url != null && !url.equals("null")&& !url.equals("NULL")&& !url.equals("")) {
final String originalURL = getImageUrl(url, approx_width, approx_height);
final Bitmap cacheImage = getCacheImage(context, originalURL);
if (cacheImage==null) {
if(progressBar!=null){
progressBar.setVisibility(View.VISIBLE);
}
if (thumbnail) {
final String thumbnailURL = getImageThumbnailUrl(url, approx_width, approx_height);
ImageLoader thumbnailLoader = Global.getInstance().getImageLoader();
networkImageView.setImageUrl(thumbnailURL, thumbnailLoader);
thumbnailLoader.get(thumbnailURL, new ImageLoader.ImageListener() {
@Override
public void onErrorResponse(VolleyError error) {
if(progressBar==null){
networkImageView.setImageResource(picture_not_found);
}
networkImageView.setTag(TAG_THUMBNAIL_ERROR);
load_Original(context, originalURL, networkImageView, progressBar, is_Store, picture_not_loaded);
}
@Override
public void onResponse(ImageLoader.ImageContainer response, boolean isImmediate) {
if (response.getBitmap() != null) {
networkImageView.setImageBitmap(response.getBitmap());
networkImageView.setTag(TAG_THUMBNAIL_RECEIVED);
load_Original(context, originalURL, networkImageView, progressBar, is_Store, picture_not_loaded);
} else if (progressBar==null) {
networkImageView.setImageResource(picture_not_found);
}
}
});
}
else{
load_Original(context,originalURL,networkImageView,progressBar,is_Store,picture_not_loaded);
}
} else {
networkImageView.setImageBitmap(cacheImage);
}
} else {
networkImageView.setImageResource(picture_not_found);
}
}
private void load_Original(final Context context,final String originalURL,final NetworkImageView networkImageView, final ProgressBar progressBar, final boolean is_Store,final int picture_not_loaded){
final Drawable temp = networkImageView.getDrawable();
final String imageviewTag = (String) networkImageView.getTag();
ImageLoader imageLoader = Global.getInstance().getImageLoader();
networkImageView.setImageUrl(originalURL, imageLoader);
imageLoader.get(originalURL, new ImageLoader.ImageListener() {
@Override
public void onErrorResponse(VolleyError error) {
if (progressBar != null) {
progressBar.setVisibility(View.GONE);
}
if (temp != null && imageviewTag != null && !imageviewTag.equals(TAG_THUMBNAIL_ERROR)) {
networkImageView.setImageDrawable(temp);
} else if (temp != null && imageviewTag != null && imageviewTag.equals(TAG_THUMBNAIL_RECEIVED)) {
networkImageView.setImageDrawable(temp);
} else {
networkImageView.setImageResource(picture_not_loaded);
}
}
@Override
public void onResponse(ImageLoader.ImageContainer response, boolean shouldAnimate) {
if (response.getBitmap() != null) {
if (progressBar != null) {
progressBar.setVisibility(View.GONE);
}
networkImageView.setImageBitmap(response.getBitmap());
if (is_Store) {
setCacheImage(context, originalURL, response.getBitmap());
}
} else {
networkImageView.setImageDrawable(temp);
}
}
});
}
private static String getImageUrl(String url, int aprox_width, int aprox_height){
int index = url.lastIndexOf('/');
String path = url.substring(0, index);
String file_name = url.substring(index + 1);
String result = path+"/"+aprox_width+"/"+aprox_height+"/"+file_name;
return result;
}
private static String getImageThumbnailUrl(String url, int approx_width, int aprox_height){
int index = url.lastIndexOf('/');
String path = url.substring(0, index);
String file_name = url.substring(index + 1);
String result = path+"/"+approx_width+"/"+aprox_height+"/tbnil"+"/"+file_name;
return result;
}
private String profile_picture_folder_name = "PP";
private void setCacheImage(Context context, String url, Bitmap bitmap){
try {
if (!getCacheDirectory(context).equals("")) {
String filename = getFileName(url);
File folder = new File(getCacheDirectory(context)+"/"+profile_picture_folder_name+"/");
if (!folder.exists()) {
folder.mkdir();
}
if (folder.exists()) {
File dest = new File(folder, filename);
FileOutputStream out = new FileOutputStream(dest);
bitmap.compress(Bitmap.CompressFormat.JPEG, 40, out);
out.flush();
out.close();
}
}
} catch (Exception e) {
Log.developer(TAG,e.getMessage());
}
}
private Bitmap getCacheImage(Context context,String url){
try {
if (!getCacheDirectory(context).equals("")) {
String filename = getFileName(url);
File folder = new File(getCacheDirectory(context)+"/"+profile_picture_folder_name+"/");
if (folder.exists()) {
FileInputStream fis = null;
File imageFile = new File(folder, filename);
if (imageFile.exists()) {
fis = new FileInputStream(imageFile);
return BitmapFactory.decodeStream(fis);
}
}
}
} catch (FileNotFoundException e) {
Log.developer(TAG, e.getMessage());
}
return null;
}
private String getCacheDirectory(Context context){
String cachePath="";
if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()) || !Environment.isExternalStorageRemovable()) {
if (context.getExternalCacheDir() != null && context.getExternalCacheDir().exists()) {
cachePath = context.getExternalCacheDir().getPath(); // most likely your null value
}
else if (context.getCacheDir() != null && context.getCacheDir().exists()) {
cachePath = context.getCacheDir().getPath();
}
} else {
if (context.getCacheDir() != null && context.getCacheDir().exists()) {
cachePath = context.getCacheDir().getPath();
}
}
return cachePath;
}
public String getFileName(String urlStr) {
return urlStr.substring(urlStr.lastIndexOf('/') + 1, urlStr.length());
}
}
推荐答案
您必须实现两个ImageLoader，一个用于缩略图，另一个用于全分辨率图像.
修改您的RequestQueue单例，如下所示:
You have to implement two ImageLoaders, one for the thumbnails and another one for the full-res images.
Modify your RequestQueue singleton as follows:
//..
private ImageLoader mImageLoader;
private ImageLoader mThumbLoader;
//...
// Then in constructor
mThumbLoader = new ImageLoader(mRequestQueue, new ImageLoader.ImageCache() { ... });
mImageLoader = new ImageLoader(mRequestQueue, new ImageLoader.ImageCache() { ... });
// And then you build two getters
protected ImageLoader getImageLoader() {
return mImageLoader;
}
protected ImageLoader getThumbLoader() {
return mThumbLoader;
}
如果为缩略图调用mThumbLoader，为完整分辨率图像调用mImageLoader，它将正常工作.
If you invoke the mThumbLoader for the thumbnails and mImageLoader for the full res images it will work fine.
这篇关于排球图像加载器ConcurrentModificationException的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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