Question:
Is there a simple way of copying a file from one directory to another?
Answer:
There is no predefined convenient method for copying a file from oneplace to another. You have to do it the old fashioned way.
Open thesource file, open the destination file, read the source file a chunkat a time into a buffer, and write the buffer to the destination file.Here is some sample code for doing that, with minimal error checking:
import java.io.*;public class copy { public static final int BUFFER_SIZE = 4096; public static final void copyStream(InputStream input, OutputStream output, byte[] buffer) throws IOException { int bytesRead; while((bytesRead = input.read(buffer)) != -1) output.write(buffer, 0, bytesRead); } public static final void main(String[] args) { byte[] buffer = new byte[BUFFER_SIZE]; BufferedInputStream input; BufferedOutputStream output; File destination; if(args.length < 2) { System.err.println("Usage: copy file1 file2 ... dest"); return; } try { destination = new File(args[args.length - 1]); buffer = new byte[BUFFER_SIZE]; if(args.length > 2 || destination.isDirectory()) { if(!destination.isDirectory()) { System.err.println( "When copying multiple files, last argument must be a directory."); return; } for(int i=0; i < (args.length - 1); ++i) { File inFile; inFile = new File(args[i]); input = new BufferedInputStream(new FileInputStream(inFile)); output = new BufferedOutputStream(new FileOutputStream( new File(destination, inFile.getName()))); copyStream(input, output, buffer); input.close(); output.close(); } } else { input = new BufferedInputStream(new FileInputStream(args[0])); output = new BufferedOutputStream(new FileOutputStream(destination)); copyStream(input, output, buffer); input.close(); output.close(); } } catch(IOException ioe) { ioe.printStackTrace(); return; } }}
