How to handle FileNotFoundException?
In my app i am storing images in the cache memory. But i got the following error using the following code. How to handle it, can anybody help me?
Exception
09-16 16:56:06.001: DEBUG/WifiService(98): enable and start wifi due to updateWifiState
09-16 17:07:36.581: WARN/System.err(21480): java.io.FileNotFoundException: /mnt/sdcard/Android/data/com.ibkr.elgifto/cache/bitmap_dc9a5b371e3c3915d12d0f32a56075022a505119.tmp (No such file or directory)
09-16 17:07:36.611: WARN/System.err(21480): at org.apache.harmony.luni.platform.OSFileSystem.openImpl(Native Method)
09-16 17:07:36.611: WARN/System.err(21480): at org.apache.harmony.luni.platform.OSFileSystem.open(OSFileSystem.java:152)
09-16 17:07:36.621: WARN/System.err(21480): at java.io.FileOutputStream.<init>(FileOutputStream.java:97)
09-16 17:07:36.621: WARN/System.err(21480): at java.io.FileOutputStream.<init>(FileOutputStream.java:69)
09-16 17:07:36.631: WARN/System.err(21480): at com.ibkr.elgifto.GiftSuggestions$itemlistadapter$4$1.run(GiftSuggestions.java:606)
Code
{
......
final File file = getCacheFile(imageUrl);
file.getParentFile().mkdirs();
file.createNewFile();
......
}
public File getCacheFile(String url)
{
// First compute the cach开发者_StackOverflowe key and cache file path for this URL
File cacheFile = null;
try
{
MessageDigest mDigest = MessageDigest.getInstance("SHA-1");
mDigest.update(url.getBytes());
final String cacheKey = bytesToHexString(mDigest.digest());
if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()))
{
cacheFile = new File(Environment.getExternalStorageDirectory()
+ File.separator + "Android"
+ File.separator + "data"
+ File.separator + GiftSuggestions.this.getPackageName()
+ File.separator + "cache"
+ File.separator + "bitmap_" + cacheKey + ".tmp");
}
}
catch (NoSuchAlgorithmException e)
{
// Oh well, SHA-1 not available (weird), don't cache bitmaps.
}
return cacheFile;
}
private String bytesToHexString(byte[] bytes)
{
// http://stackoverflow.com/questions/332079
StringBuffer sb = new StringBuffer();
for (int i = 0; i < bytes.length; i++)
{
String hex = Integer.toHexString(0xFF & bytes[i]);
if (hex.length() == 1) {
sb.append('0');
}
sb.append(hex);
}
return sb.toString();
}
Since its a cache , there is always a chance that it is deleted before you fetch.
Therefore you check for file existence and if file exists, use it otherwise fetch it from the original source.
e.g.
File f = new File(path);
if(f.exists()) {
//Use the file
} else {
//Fetch from the original source
}
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