Is "C:\cai\cs151"
a relative or an absolute path name?
Absolute. (It is the absolute path name of a directory).
The exists()
method tests if a file exists.
Do this when a program is about to create
a file, and you don't want to destroy a previous file of the same name.
Here is a start on a program:
import java.io.*; class CopyBytes { public static void main ( String[] args ) { DataInputStream instr; DataOutputStream outstr; if ( args.length != 3 || !args[1].toUpperCase().equals("TO") ) { System.out.println("java CopyBytes source to destination"); return; } File inFile = new File( args[0] ); File outFile = new File( _____________ ); if ( outFile._____________ ) { System.out.println( args[2] + " already exists"); return; } if ( ____inFile._____________ ) { System.out.println( args[0] + " does not exist"); return; } . . . . } }
Now the program tests that: (1) the destination file does not already exist, and that (2) the source file does exist.