Converting String to ArrayList

[john price]

I am writing a Client and Server instant message application. It is well on its way with multiple color support, private messaging, hacker protection, mod privileges (only me for now) that can boot people off permanently or once, etc, etc. Anyway, my point is that it is working fine and well. In my clients, I have a filter. It filters out bad words for both the name and the message. It looks something like this:

public void checkName() {
        if (nameField.getText().toLowerCase().contains("badword1")) { //nameField = JTextField for the name of the sender
	cuss = true;
	}
	else if (nameField.getText().toLowerCase().contains("badword2")) {
	cuss = true;
	}
        else if (nameField.getText().toLowerCase().contains("illegal characters & such") {
illegalcharacter = true;
        }
}

There is about 500 lines of code just doing this. I thought it would be more efficient speed wise, simplicity wise, and OOP wise to do this in an ArrayList.
I have never actually used one so I just wanted to be sure I can do this...
Here is what I think I can change this to...

ArrayList<String> badWords = new ArrayList<String>();
badWords.add("badword1");
badWords.add("badword2");
ArrayList<String> illegalCharacters = new ArrayList<String>();
illegalCharacters.add("illegalcharacter1");
illegalCharacters.add("illegalcharacter2");
public void checkName() {
if (nameField.getText().toLowerCase().contains(badWords)) {
	cuss = true;
	}
        else if (nameField.getText().toLowerCase().contains(illegalCharacters) {
illegalcharacter = true;
        }
}

I was wondering whether this would work and if I am doing it right. Thanks guys!
cc11rocks aka John Price

[Sai Hegde]

Well, Don't you think it is a mantainability issue having all the string constants defined in your code?
Pull them out to a properties file and then check your input against it.
You could also have enums defined for both just in case and check against those.

[Paul Clapham]

I don't even think it will compile. (Didn't you try it?)

Anyway you don't want to see if a String contains an ArrayList of Strings, because that doesn't make any sense. You want to see whether the String contains any of the Strings in the ArrayList. For which you have to loop through the ArrayList and consider each individual String.

[Sai Hegde]

Nice catch, Paul.

[john price]

for (int x = 0, x <= badWords.length(), x++) {
if (nameField.getText().toLowerCase().contains(badWords[x])) {  
    cuss = true;  
    }  
}
for (int y = 0, y <;= illegalCharacters.length(), y++) {
if (nameField.getText().toLowerCase().contains(illegalCharacters[y])) {  
    cuss = true;  
    }  
}

The first example I showed does in fact work. The second example I did not try. I have not used ArrayLists before and was kind of confused how to get this working. Yes, I have read the APIs. Would this work?
Thanks,
John Price aka cc11rocks

[Paul Clapham]

Would it work? You should know by now that the answer to this question, in the programming context, can never be "yes". At best it can be "probably", because there's always some little thing you didn't mention. But yeah, probably it would work. I would use a so-called "new" for loop (been in the language for about 8 years now) and I would break out of the loop as soon as I found a bad word:

for (String badWord: badWords) {
  if nameField.getText().toLowerCase().contains(badWord) {
    cuss = true;
    break;
  }
}

No point in continuing to check the other 859 bad words when you've found one already!

[Sai Hegde]

Why not do it the reverse way

badwords.contains(nameField.getText().toLowerCase())
...

[Rob Camick]

You should probably be using a Set not a List for this. A Set is more efficient when doing the search for a given Object.

[john price]

SO something like this?

Set<String> badWords = new Set<String>;
badWords.add("badword1");
badWords.add("badword2");


//later

for (String badWord: badWords) {  
  if nameField.getText().toLowerCase().contains(badWord) {  
    cuss = true;  
    break;  
  }  
} 

[Rob Camick]

No need for a loop. The contains method searches the Set:

if (badwords.contains( nameField.getText().toLowerCase() )
    cuss = true.

[Sai Hegde]

Yes, like I mentioned before. Do a contains on your collection rather than the other way around.

[john price]

I tried it and it only works if the JTextField is EXACTLY the badword. Example code:

import java.util.*;
import javax.swing.*;
public class fakeServer {
public static void main(String[] args) {
ArrayList<String> badWords = new ArrayList<String>();  
badWords.add("badword1");  
badWords.add("badword2");  
JTextField hi = new JTextField("badword1j");
  
for (String badWord: badWords) {    
  if (badWords.contains(hi.getText())) {
  System.out.println(hi.getText());
    hi.setText("hi1");
    break;
  }
}
System.out.println(hi.getText()); 
}
}

C:\Users\cc11rocks\Desktop>java fakeServer
badword1j

if I change line eight to

JTextField hi = new JTextField("badword1");

or

JTextField hi = new JTextField("badword2");

The output is:

C:\Users\cc11rocks\Desktop>java fakeServer
badword1
hi1

or

C:\Users\cc11rocks\Desktop>java fakeServer
badword2
hi1

How do I fix this?
If I try to do the string.contains(stringarray), which would work, it return an error that that cannot happen.
Thanks,
John Price aka cc11rocks

[john price]

This works though:

import java.util.*;
import javax.swing.*;
public class fakeServer {
public static void main(String[] args) {
//ArrayList<String> badWords = new ArrayList<String>();  
//badWords.add("badword1");  
//badWords.add("badword2");  
String []  badWords = new String [] {"badword1", "badword2"};
JTextField hi = new JTextField("badword1j");
  
for (String badWord: badWords) {    
  if (hi.getText().contains(badWord)) {
  System.out.println(hi.getText());
    hi.setText("hi1");
    break;
  }
}
System.out.println(hi.getText()); 
}
}

[john price]

Found the solution to second to last post (from this post):
it should be
badWord not badWords as badWord is a String and badWords is an ArrayList.
Which of the above solutions should I use?
Thanks,
cc11rocks aka John Price

[Sai Hegde]

import java.util.*;
import javax.swing.*;
public class fakeServer {
public static void main(String[] args) {
ArrayList<String> badWords = new ArrayList<String>();  
badWords.add("badword1");  
badWords.add("badword2");  
JTextField hi = new JTextField("badword1j");
  
if (badwords.contains(hi.getText().trim())) {
hi.setText(""); 
System.out.println("Please mind your words!")
}
}

[john price]

Sai Hedge, your code does not work. It doesn't return any errors, but it doesn't work. Here is your compilable code (had to modify 2 things):

import java.util.*;  
import javax.swing.*;  
public class fakeServer {  
public static void main(String[] args) {  
ArrayList<String> badWords = new ArrayList<String>();    
badWords.add("badword1");    
badWords.add("badword2");    
JTextField hi = new JTextField("badword1j");  
    
if (badWords.contains(hi.getText().trim())) {  
hi.setText("");   
System.out.println("Please mind your words!");
}  
}
}

C:\Users\cc11rocks\Desktop>java fakeServer

C:\Users\cc11rocks\Desktop>

,
cc11rocks aka John Price

[Sai Hegde]

Sure, it wouldn't like the way you are running it.
How do you even get the Swing Frame to show up. The JTextField that you are using is a Swing component and should be used within a Panel/Form(some Swing) container.

For what you are looking at, here is the code. Now you'd need to dig into more on the Swing parts.

import java.util.ArrayList;

public class fakeserver {
	public static void main(String[] args) {
ArrayList<String> badWords = new ArrayList<String>();  
badWords.add("badword1");  
badWords.add("badword2");  
  
if (badWords.contains("badword1")) {
//hi.setText(""); 
System.out.println("Please mind your words!");
}
}

}

[john price]

This is an example. My real code is over 600 and 800 lines (two versions of the program, one for mods and users). Currently, I am using this way:

for (String badWord : badWords) {
		if (hi.getText().toLowerCase().contains(badWord)) { //in my real code it is outgoing and nameField for the JTextFields
		cuss = true;
		break;
	}
	}

[Rob Camick]

It was wrong before and its still wrong now.

[john price]

Rob, are you talking to me?
If so, I do not understand how I am.

[Rob Camick]

Well, I'm tired of repeating myslelf.

[Luigi Plinge]

You need to split the text input up into words so that you can check each one against your Set.

import java.util.Arrays;
import java.util.HashSet;

        String[] swear = {"swear1", "swear2", "swear3"}; // Read this in from a file
        HashSet<String> illegal = new HashSet<String>();
        illegal.addAll(Arrays.asList(swear));
        
        String s = "This is. A swear1, test-sentence. swear2"; // Read this from text field
        String[] words = s.split("\\W");
        for (String w : words) {
            if (illegal.contains(w)) s = s.replace(w, "!@*%#");
        }
        System.out.println(s);

Outputs
This is. A !@*%#, test-sentence. !@*%#