Delete file or Directory
In this example we are discussing the deletion of a
file or a directory by using a java program. We pass the file name or the
directory name to which we want to delete. The given program deletes an existing
file if the file is not write protected. this example also deletes an existing
directory if the directory is empty otherwise delete operation fails.
Description of program:
In the given example first of all we check the string
array variable str for its length, if we pass a command line argument
then its value will not be null and rest of the operation is performed. After
that we are creating a delete() method. In this method first we are creating a
file object that contains the file or directory name to be deleted. Then we
check for file whether it exists or not and if it exists checks whether it is
write protected or not and calls the delete() on this file, If it is not a file then we check for the directory and
also checks whether it is empty or not and after that we are calling the
delete() method on this object and takes the result in a Boolean
type variable success. If this variable has the value true then the given
directory is deleted successfully otherwise If
condition gets executed and the message Deletion: deletion failed is
displayed. In our case we are creating a directory named delte that is
not empty and then we are trying to delete it, thats why we got the message Can
not delete as directory is not empty: delte.
Here is the code of this program:
import java.io.*;
public class DeleteOperation {
public static void main(String[] str) {
if (str.length != 1) {
System.err.println("Deleting file or directory");
System.exit(0);
}
try {
delete(str[0]);
}
catch (IllegalArgumentException e) {
System.err.println(e.getMessage());
}
}
public static void delete(String filename) {
File file = new File(filename);
if (!file.exists()) fail("No such file or directory
exist: " + filename);
if (!file.canWrite()) fail("Can not delete as it is write
protected: " + filename);
if (file.isDirectory()) {
String[] files = file.list();
if (files.length > 0) fail("Can not delete as directory
is not empty: " + filename);
}
boolean success = file.delete();
if (!success) fail("Delete: deletion failed");
}
protected static void fail(String msg) throws IllegalArgumentException {
throw new IllegalArgumentException(msg);
}
}
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Here is the output:
C:\Examples>java DeleteOperation delte
Can not delete as directory is not empty: delte |
Download of this
program.
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