Problem running a program practicing with Arrays and Classes

Hello all. I am having a problem running my program. It produces no output and goes on infinitely. I can't figure out what the problem is. Any help spotting anything unusual with my code would be appreciated. Thanks.

public class LetterInventory {
	public static void main(String[] args) {
		LetterInventory inventory1 = new LetterInventory("Brandon Peeples");
	}

private String data;
	int[] inventory = new int[26];
	
	public LetterInventory(String data) {
		String lower = data.toLowerCase();
		data = "";
		for (int i = 0; i < lower.length(); i++) {
			char ch = lower.charAt(i);
			if (Character.isLetter(ch)) {
				data += ch;
			}
		}
	}
	
	public int get(char letter) {
		int count = 0;
		for (int i = 0; i < data.length(); i++){
			if (Character.isLetter(letter)) {
				count++;
			}
		}
		return count;
	}
	
	public void set(char letter, int value) {
		for(int i = 0; i < inventory.length; i++){
			char ch = data.charAt(i);
			if (letter == ch) {
				inventory[letter - 'a'] += value;
				break;
			}
		}
	}
	
	public int size() {
		int sum = data.length();
		return sum;
	}
	
	public boolean isEmpty() {
		if(inventory == null){
			return true;
		}
		return false;
	}
	
	public String toString() {
		for (int i = 0; i < inventory.length; i++) {
			data += inventory[(char) 'a' + i];
		}
		return "[" + data + "]";
	}
	
	public LetterInventory add(LetterInventory other) {
		LetterInventory inventoryAdded = new LetterInventory(other.data + data);
		return inventoryAdded;
	}
	
	public LetterInventory subtract(LetterInventory other) {
		String data = "";
		for (int i = 0; i < inventory.length; i++) {
			this.inventory[i] -= inventory[i];
			data += inventory[(char) 'a' + i];
			if (this.inventory[i] < 0) {
				inventory = null;
				break;
			}
		}
		LetterInventory inventorySubtracted = new LetterInventory(data);
		return inventorySubtracted;
	}
}

EDIT: Added a main method

Hello Brandon,
Are you using a debugger? If so have you set breakpoints in your code?
Let us know/thanks

It definitely compiles, however I am getting the following error message when I attempt to execute it:

Exception in thread "main" java.lang.NoSuchMethodError: main

A Google of that error message indicates:
"The Java VM requires that the class you execute with it have a main method at which to begin execution of your application. discusses the main method in detail."

Joe Boman wrote:It definitely compiles, however I am getting the following error message when I attempt to execute it:

Exception in thread "main" java.lang.NoSuchMethodError: main

So which line causes the exception?

Dear, your class is public...

public class LetterInventory{}

Where is your main method ?

public static void main(String args[]) ?

Thanks for the replies. I should have mentioned the fact that main is in a different class called "LetterInventoryMain.java" . I tried to execute the program from a different class using the object from "LetterInventory.java" . I think I will just make a main method in the class I posted instead. I'll see if I get some output that way. I'll post an update once I try.

I think it is looping in the for loop in the class constructor.

Hope it's ok that I dummied up a "main" module and instantiated the class passing it the string "ABCDE". As a result, the for loop is repeatedly building in lower case "abcdeabcde...etc...etc".

I don't know what this class is supposed to do, but ,but I have a feeling that class behavior may not be intended?

Here is the "main" I added at the bottom of the class:

I appreciate the feedback Joe. The class is supposed to accept a String and report the amount of letters (in brackets) in the String ignoring the case and all non alphabetic characters. For example:

LetterInventory inventory1 = new LetterInventory("Pizza123");

should produce: "[aipzz]"

Sure, NP Brandon,

When I modify main to pass the string "Pizza123" (which does include numbers), the constructor is carrying out the same unfortunate looping behavior. No change in behavior with numbers.

I don't want to provide suggestions on how to fix this, but the problem became more clear to me when I executed it line by line in a debugger. I like to cheat that way

I use BlueJ, but that's only because it is familiar to me.
thanks/Joe

Ahhh thanks Joe. I think I'll give the debugger a try. I am currently using Eclipse for the first time. I know there is a debugger and I'll try to use it. I previously used something without a debugger.