Input and Output - Java - page 385

Discussion

This operation is fairly common, so I've packaged it as a set of methods in a class called
FileIO in my utilities package com.darwinsys.util . Here's a simple test program that uses
it to copy a source file to a backup file:

src/demo/java/io/FileIoDemo.java

package package com . darwinsys . io ;

import import java.io.IOException java.io.IOException ;

public public class class FileIoDemo FileIoDemo {

public public static static void void main ( String [] av ) {

try try {

FileIO . copyFile ( "FileIO.java" , "FileIO.bak" );
FileIO . copyFile ( "FileIO.class" , "FileIO-class.bak" );
} catch

catch ( IOException e ) {
System . err . println ( e );

}

}

}

How does FileIO work? Its copyFile method takes several forms, depending on whether
you have two filenames, a filename and a PrintWriter , and so on. The code for FileIO it-
self is shown in Example 10-6 .

Example 10-6. src/main/java/com/darwinsys/io/FileIO.java
package package com . darwinsys . io ;

import import java.io.* java.io.* ;

import import java.util.Enumeration java.util.Enumeration ;

import import java.util.jar.JarEntry java.util.jar.JarEntry ;

import import java.util.jar.JarFile java.util.jar.JarFile ;

import import com.darwinsys.lang.StringUtil com.darwinsys.lang.StringUtil ;

import import com.darwinsys.util.Debug com.darwinsys.util.Debug ;

/**
* Some file I-O primitives reimplemented in Java.
* All methods are static, since there is no state.
*/
public public class class FileIO FileIO {