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@fnk0
Last active March 21, 2016 18:06
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A simple cache manager for Android
package okstate.edu.canopeo.helpers;
import android.content.Context;
import android.graphics.Bitmap;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* Created by <a href="mailto:marcusandreog@gmail.com">Marcus Gabilheri</a>
*
* @author Marcus Gabilheri
* @version 1.0
* @since 7/4/15.
*/
public final class CacheManager {
private static final long MAX_SIZE = 104857600L; // 100MB
public static final long FIVE_MB = 5242880L; // 5 MB
private CacheManager() {
}
public static String cacheData(Context context, byte[] data, String name) throws IOException {
File cacheDir = context.getCacheDir();
long size = getDirSize(cacheDir);
long newSize = data.length + size;
cleanIfNecessary(context, size);
File file = new File(cacheDir, name);
FileOutputStream os = new FileOutputStream(file);
try {
os.write(data);
}
finally {
os.flush();
os.close();
}
return file.getPath();
}
public static String cacheImage(Context context, Bitmap data, String name) throws IOException {
File cacheDir = context.getCacheDir();
long size = getDirSize(cacheDir);
long newSize = data.getByteCount() + size;
cleanIfNecessary(context, newSize);
File file = new File(cacheDir, name);
OutputStream os = new FileOutputStream(file);
try {
data.compress(Bitmap.CompressFormat.JPEG, 90, os);
}
finally {
os.flush();
os.close();
}
return file.getPath();
}
public static void cleanIfNecessary(Context context, long dataSize) {
File cacheDir = context.getCacheDir();
long size = getDirSize(cacheDir);
long newSize = dataSize + size;
if (newSize > MAX_SIZE) {
cleanDir(cacheDir, newSize - MAX_SIZE);
}
}
public static byte[] retrieveData(Context context, String name) throws IOException {
File cacheDir = context.getCacheDir();
File file = new File(cacheDir, name);
if (!file.exists()) {
// Data doesn't exist
return null;
}
byte[] data = new byte[(int) file.length()];
FileInputStream is = new FileInputStream(file);
try {
is.read(data);
}
finally {
is.close();
}
return data;
}
private static void cleanDir(File dir, long bytes) {
long bytesDeleted = 0;
File[] files = dir.listFiles();
for (File file : files) {
bytesDeleted += file.length();
file.delete();
if (bytesDeleted >= bytes) {
break;
}
}
}
private static long getDirSize(File dir) {
long size = 0;
File[] files = dir.listFiles();
for (File file : files) {
if (file.isFile()) {
size += file.length();
}
}
return size;
}
}
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