Mega Code Archive
Utility class for synchronizing filesdirectories
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//$Id: FileHelper.java 15522 2008-11-05 20:06:43Z hardy.ferentschik $
//Revised from hibernate search util
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileChannel;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
/**
* Utility class for synchronizing files/directories.
*
* @author Emmanuel Bernard
* @author Sanne Grinovero
* @author Hardy Ferentschik
*/
public abstract class FileHelper {
private static final int FAT_PRECISION = 2000;
public static final long DEFAULT_COPY_BUFFER_SIZE = 16 * 1024 * 1024; // 16 MB
public static boolean areInSync(File source, File destination) throws IOException {
if ( source.isDirectory() ) {
if ( !destination.exists() ) {
return false;
}
else if ( !destination.isDirectory() ) {
throw new IOException(
"Source and Destination not of the same type:"
+ source.getCanonicalPath() + " , " + destination.getCanonicalPath()
);
}
String[] sources = source.list();
Set<String> srcNames = new HashSet<String>( Arrays.asList( sources ) );
String[] dests = destination.list();
// check for files in destination and not in source
for ( String fileName : dests ) {
if ( !srcNames.contains( fileName ) ) {
return false;
}
}
boolean inSync = true;
for ( String fileName : sources ) {
File srcFile = new File( source, fileName );
File destFile = new File( destination, fileName );
if ( !areInSync( srcFile, destFile ) ) {
inSync = false;
break;
}
}
return inSync;
}
else {
if ( destination.exists() && destination.isFile() ) {
long sts = source.lastModified() / FAT_PRECISION;
long dts = destination.lastModified() / FAT_PRECISION;
return sts == dts;
}
else {
return false;
}
}
}
public static void synchronize(File source, File destination, boolean smart) throws IOException {
synchronize( source, destination, smart, DEFAULT_COPY_BUFFER_SIZE );
}
public static void synchronize(File source, File destination, boolean smart, long chunkSize) throws IOException {
if ( chunkSize <= 0 ) {
System.out.println("Chunk size must be positive: using default value." );
chunkSize = DEFAULT_COPY_BUFFER_SIZE;
}
if ( source.isDirectory() ) {
if ( !destination.exists() ) {
if ( !destination.mkdirs() ) {
throw new IOException( "Could not create path " + destination );
}
}
else if ( !destination.isDirectory() ) {
throw new IOException(
"Source and Destination not of the same type:"
+ source.getCanonicalPath() + " , " + destination.getCanonicalPath()
);
}
String[] sources = source.list();
Set<String> srcNames = new HashSet<String>( Arrays.asList( sources ) );
String[] dests = destination.list();
//delete files not present in source
for ( String fileName : dests ) {
if ( !srcNames.contains( fileName ) ) {
delete( new File( destination, fileName ) );
}
}
//copy each file from source
for ( String fileName : sources ) {
File srcFile = new File( source, fileName );
File destFile = new File( destination, fileName );
synchronize( srcFile, destFile, smart, chunkSize );
}
}
else {
if ( destination.exists() && destination.isDirectory() ) {
delete( destination );
}
if ( destination.exists() ) {
long sts = source.lastModified() / FAT_PRECISION;
long dts = destination.lastModified() / FAT_PRECISION;
//do not copy if smart and same timestamp and same length
if ( !smart || sts == 0 || sts != dts || source.length() != destination.length() ) {
copyFile( source, destination, chunkSize );
}
}
else {
copyFile( source, destination, chunkSize );
}
}
}
private static void copyFile(File srcFile, File destFile, long chunkSize) throws IOException {
FileInputStream is = null;
FileOutputStream os = null;
try {
is = new FileInputStream( srcFile );
FileChannel iChannel = is.getChannel();
os = new FileOutputStream( destFile, false );
FileChannel oChannel = os.getChannel();
long doneBytes = 0L;
long todoBytes = srcFile.length();
while ( todoBytes != 0L ) {
long iterationBytes = Math.min( todoBytes, chunkSize );
long transferredLength = oChannel.transferFrom( iChannel, doneBytes, iterationBytes );
if ( iterationBytes != transferredLength ) {
throw new IOException(
"Error during file transfer: expected "
+ iterationBytes + " bytes, only " + transferredLength + " bytes copied."
);
}
doneBytes += transferredLength;
todoBytes -= transferredLength;
}
}
finally {
if ( is != null ) {
is.close();
}
if ( os != null ) {
os.close();
}
}
boolean successTimestampOp = destFile.setLastModified( srcFile.lastModified() );
if ( !successTimestampOp ) {
System.out.println("Could not change timestamp for {}. Index synchronization may be slow. " + destFile );
}
}
public static void delete(File file) {
if ( file.isDirectory() ) {
for ( File subFile : file.listFiles() ) {
delete( subFile );
}
}
if ( file.exists() ) {
if ( !file.delete() ) {
System.out.println( "Could not delete {}" + file );
}
}
}
}
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