array confusion

[torrinment]

Question about two peices of code
1.

{
		int i=0;
		int j=0;
		int total=0;
		while(Character.isWhitespace(lines[i].charAt(j)))
		{
			total++;
			i++;
			j++;
		}
		return total;

this should show the number of characters in an already loadaded file but it doesnt

2How do you take a file with blank lines in it and crunch it up for example
this is

a file

now
should turn into

this
is
a file
now

[Uladzimir]

I)

int total=0;
for (int lineIndex=0; lineIndex < lines.length; lineIndex++) {
	String str = lines[lineIndex];	
	if ( int j = 0; j < str.length; j++ ) {
		if (!Character.isWhitespace(str.charAt(j))) { // if you do not want to calculate whitespaces 
			total++;
		}
	}
}

II)

BufferedReader br = new BufferedReader(XXX); // XXX - your input stream e.g. FileInputStream
 String line;
 while ((line = br.readLine()) != null) {
      if (line.trim().size()str == 0) {
      	continue; // skip empty string
      }
      ....      
 }

[torrinment]

Can you show it without continue and also your the first one doesnt work

[Uladzimir]

for (int lineIndex=0; lineIndex < lines.length; lineIndex++) {
	 String line = lines[lineIndex];	
	 if (!line.trim().size() == 0) {
        	System.out.println(line);
...

   }
}

[torrinment]

the character count one doesnt work either

{
		int i=0;
		int j=0;
		int total=0;
		while(Character.isWhitespace(lines[i].charAt(j)))
		{
			total++;
			i++;
			j++;
		}
		return total;

[Uladzimir]

The character count:

 int total = 0;
        String[] lines = new String[] {
                "abcdef", "123", "qwer ty" // 15 chars + 1 space
        };
        for (int lineIndex=0; lineIndex < lines.length; lineIndex++) {
            String str = lines[lineIndex];
            for (int j = 0; j < str.length(); j++ ) {
                if (!Character.isWhitespace(str.charAt(j))) { // if you do not want to calculate whitespaces
                    total++;
                }
            }
        }
        System.out.println(total);

[torrinment]

do you know what a nullpointer exception is

[Uladzimir]

Second example:

String[] lines = new String[] {
                "this", "   ", "is", "a" , " ",  "test" };
        for (int lineIndex=0; lineIndex < lines.length; lineIndex++) {
	    String line = lines[lineIndex];
	    if (!(line.trim().length() == 0)) {
        	System.out.println(line);
            }
        }

PS: I often post a programs which I don't check. I think small errors like misprints you can correct yourself.

[Uladzimir]

do you know what a nullpointer exception is

Yes I know. It happens when you try to do with something that don't exsists.

For example:
String s = null;
s.trim(); // throws NullPointerException

[torrinment]

that works but gives me a nullpointerexception how do i fix this like it does what it supposed to but then i get that exceptio n

[Uladzimir]

that works but gives me a nullpointerexception how do i fix this like it does what it supposed to but then i get that exceptio n

It's difficult to answer because I don't know your code. Please attach a whole your application or am exception stack trace.

BTW: check that you nowhere set empty values to variables.

[torrinment]

no im just talkin about both the character count you showed me and the eliminate vspace

public static int charCount(String[]lines)
	{
		 int total = 0;
	       for (int i=0; i < lines.length; i++) 
	       {
	    	   for (int j = 0; j < lines[i].length(); j++ ) 
	       {
	    	   if (!Character.isWhitespace(lines[i].charAt(j))) {
	    		   total++;
	                }
	            }
	        }
	        System.out.println(total);
		return total;
	}

and

public static void EliminateVSpace(String[]lines)
	{
        for (int lineIndex=0; lineIndex < lines.length; lineIndex++) {
	    String line = lines[lineIndex];
	    if (!(line.trim().length() == 0)) {
        	System.out.println(line);
            }
        }

}

[Uladzimir]

I understand. The exception happens because you pass lines with empty values.
For example
if you pass such array:
String[] lines = new String[] {"this", " ", "is", null, "a", "test" };
it will produce an exception.

[torrinment]

so i fix it by...