从ListView的URL的Android加载图像 [英] Android Loading Image from URL in ListView
本文介绍了从ListView的URL的Android加载图像的处理方法，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
我读IMAGEURL的从RSS XML文件，并在列表视图显示，我能够显示图像，但得到例外的一些图片的URL
I am Reading imageURL's From Rss Xml file and displaying in List View,I'm able to display the images ,but getting Exception For Some Image URL's
java.io.FileNotFoundException
下面我的code：
public class ImageLoader {
MemoryCache memoryCache=new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
String type;
public ImageLoader(Context context,String type){
fileCache=new FileCache(context);
executorService=Executors.newFixedThreadPool(5);
this.type=type;
}
public ImageLoader(Context context){
fileCache=new FileCache(context);
executorService=Executors.newFixedThreadPool(5);
}
final int stub_id = R.drawable.toriimg;
public void DisplayImage(String url, ImageView imageView)
{
//Log.d("ImageLoader","Iam in DisplayImage");
imageViews.put(imageView, url);
Bitmap bitmap=memoryCache.get(url);
if(bitmap!=null)
imageView.setImageBitmap(bitmap);
else
{
queuePhoto(url, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, ImageView imageView)
{
PhotoToLoad p=new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
private Bitmap getBitmap(String url)
{
File f=fileCache.getFile(url);
//from SD cache
Bitmap b = decodeFile(f);
if(b!=null)
return b;
//from web
try {
Bitmap bitmap=null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
InputStream is=conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
} catch (Exception ex){
ex.printStackTrace();
return null;
}
}
//decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f){
try {
//decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(f),null,o);
//Find the correct scale value. It should be the power of 2.
int REQUIRED_SIZE=70;
int width_tmp=o.outWidth, height_tmp=o.outHeight;
int scale=1;
if(this.type=="SongPlayActivity")
{
scale=1;
}
else if(this.type=="AlbumPlayListActivity")
{
scale=1;
}
else
{
while(true){
if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
break;
width_tmp/=2;
height_tmp/=2;
scale*=2;
}
}
//decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {}
return null;
}
//Task for the queue
private class PhotoToLoad
{
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i){
url=u;
imageView=i;
}
}
class PhotosLoader implements Runnable {
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad){
this.photoToLoad=photoToLoad;
}
public void run() {
if(imageViewReused(photoToLoad))
return;
Bitmap bmp=getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if(imageViewReused(photoToLoad))
return;
BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad);
Activity a=(Activity)photoToLoad.imageView.getContext();
a.runOnUiThread(bd);
}
}
boolean imageViewReused(PhotoToLoad photoToLoad){
String tag=imageViews.get(photoToLoad.imageView);
if(tag==null || !tag.equals(photoToLoad.url))
return true;
return false;
}
//Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable
{
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p){bitmap=b;photoToLoad=p;}
public void run()
{
if(imageViewReused(photoToLoad))
return;
if(bitmap!=null)
photoToLoad.imageView.setImageBitmap(bitmap);
else
photoToLoad.imageView.setImageResource(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}
LogCat中：
LogCat:
05-14 13:00:09.640: W/System.err(11295): java.io.FileNotFoundException: http://www.toucheradio.com/hostphotos/kiran Abbaraju.jpg
05-14 13:00:09.640: W/System.err(11295): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:521)
05-14 13:00:09.640: W/System.err(11295): at com.teluguone.torilt.model.ImageLoader.getBitmap(ImageLoader.java:89)
05-14 13:00:09.640: W/System.err(11295): at com.teluguone.torilt.model.ImageLoader.access$0(ImageLoader.java:72)
05-14 13:00:09.640: W/System.err(11295): at com.teluguone.torilt.model.ImageLoader$PhotosLoader.run(ImageLoader.java:163)
05-14 13:00:09.640: W/System.err(11295): at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:444)
05-14 13:00:09.640: W/System.err(11295): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
05-14 13:00:09.640: W/System.err(11295): at java.util.concurrent.FutureTask.run(FutureTask.java:138)
05-14 13:00:09.640: W/System.err(11295): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
05-14 13:00:09.640: W/System.err(11295): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
05-14 13:00:09.640: W/System.err(11295): at java.lang.Thread.run(Thread.java:1019)
难道任何一个建议？
Could any one Suggest?
推荐答案
正如我说在我的意见之一，如果你带codeHTTP：//，您将获得的http％3A％2F％2F 。该URLEn coder.en code方法是为编码查询字符串值，而不是整个的URL。
As I say in one of my comments, if you encode "http://" you will get "http%3A%2F%2F". The URLEncoder.encode method is for encoding query string values rather than whole URLs.
因此，一种解决方案可以是：
So, one solution can be:
String query = URLEncoder.encode("kiran Abbaraju.jpg", "utf-8");
String url = "http://www.toucheradio.com/hostphotos/" + query;
但是，一个更清洁的解决方案是：
But a cleaner solution is:
String wrongUrl = "http://www.toucheradio.com/hostphotos/kiran Abbaraju.jpg";
URL url = new URL(wrongUrl);
URI uri = new URI(url.getProtocol(), url.getUserInfo(), url.getHost(), url.getPort(), url.getPath(), url.getQuery(), url.getRef());
url = uri.toURL();
更新：
在您getBitmap（字符串URL）尝试：
In your getBitmap(String url) try:
...
//from web
try {
Bitmap bitmap=null;
URL imageUrl = new URL(url);
URI uri = new URI(imageUrl.getProtocol(), imageUrl.getUserInfo(), imageUrl.getHost(), imageUrl.getPort(), imageUrl.getPath(), imageUrl.getQuery(), imageUrl.getRef());
imageUrl = uri.toURL();
...
这篇关于从ListView的URL的Android加载图像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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