The following code is giving a null pointer exception at line no 11:java.util.Arrays.sort(dir).
CODE:
import java.io.File;

public class Ls {
public static void main(String args[])
{
String[] dir = new java.io.File("test").list();
java.util.Arrays.sort(dir);
File f[] = new File("test").listFiles();
int len1 = dir.length;
for (int i=0;i<len1; i++)
{
System.out.println(dir[i]);
String name = f[i].getName();
System.out.println(name);
int j=name.indexOf('.');
System.out.println(j);
String newname = name.substring(0,j) + "_BS" + name.substring(j,name.length());
System.out.println(newname);
File newFileName=new File(f[i].getParentFile(), newname);
System.out.println("newFileName="+newFileName);
f[i].renameTo(newFileName);
}
}
}

Can somebody sort it out.