FileComparepublic class FileCompare extends Object
| Fields Summary |
|---|
| public static boolean | debug |
| Methods Summary |
|---|
| public static boolean | cmp(java.io.File a, java.io.File b)
if ( !a.isFile() || !b.isFile()){
if ( debug ){
debugPrint(a, b, "not both plain files");
}
return false; // NotAFile compares unequal.
}
if ( a.length() != b.length() ){
if ( debug ){
debugPrint(a, b, "different lengths");
}
return false; // different lengthes cannot be the same.
}
try {
FileInputStream astream = null;
FileInputStream bstream = null;
try {
astream = new FileInputStream( a );
bstream = new FileInputStream( b );
long flength = a.length(); // == b.length(), remember?
int bufsize = (int)Math.min( flength, 1024 );
byte abuf[] = new byte[ bufsize ];
byte bbuf[] = new byte[ bufsize ];
long n = 0;
while ( n < flength ){
int naread = astream.read( abuf );
int nbread = bstream.read( bbuf );
if ( naread != nbread ) return false; // oops.
for ( int i = 0; i < naread; i++ ){
if ( abuf[i] != bbuf[i] ){
if ( debug ){
debugPrint(a, b, "differ at byte "+(n+i) );
}
return false;
}
}
n += naread;
}
} finally {
if ( astream != null ) astream.close();
if ( bstream != null ) bstream.close();
}
} catch ( IOException e ){
e.printStackTrace();
return false;
}
if ( debug ){
debugPrint(a, b, "are the same");
}
return true;
| | public static void | conditionalCopy(java.io.File fromFile, java.io.File toFile)
if ( ! cmp( fromFile, toFile ) )
cpy( fromFile, toFile );
| | public static boolean | cpy(java.io.File a, java.io.File b)
try {
FileInputStream astream = null;
FileOutputStream bstream = null;
try {
astream = new FileInputStream( a );
bstream = new FileOutputStream( b );
long flength = a.length();
int bufsize = (int)Math.min( flength, 1024 );
byte buf[] = new byte[ bufsize ];
long n = 0;
while ( n < flength ){
int naread = astream.read( buf );
bstream.write( buf, 0, naread );
n += naread;
}
} finally {
if ( astream != null ) astream.close();
if ( bstream != null ) bstream.close();
}
} catch ( IOException e ){
e.printStackTrace();
return false;
}
return true;
| | private static void | debugPrint(java.io.File a, java.io.File b, java.lang.String msg)
System.err.print(a.getPath());
System.err.print(", ");
System.err.print(b.getPath());
System.err.print(" ");
System.err.println( msg );
| | public static void | main(java.lang.String[] args)
debug = true;
conditionalCopy( new File( args[0] ), new File( args[1] ) );
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