I'm working on a utility class for my school homework and I've encountered a runtime exception that I can't make sense of. The code compiles without any issues, but when I run it, it throws an exception that has me scratching my head. If anyone can figure out what's going wrong, I'd really appreciate it! Here's the code snippet for reference:
```java
import java.util.*;
public class ConfigParser {
private static final Map defaults = new HashMap();
static {
defaults.put("maxUsers", 10);
defaults.put("timeout", 5000);
defaults.put("retries", 3);
}
public static void main(String[] args) {
Map config = new HashMap(defaults);
for (String key : config.keySet()) {
// Update values based on some dynamic logic
config.put(key, config.get(key) + key.length());
}
System.out.println("Final config: " + config);
}
}
```
5 Answers
It looks like you are modifying the values of the map while going through its keys, which is typically alright. The exception might be stemming from something else entirely, so double-check your logic or any other running programs that might be causing confusion!
First things first, what's the exact exception you're getting? Knowing the error message is crucial for figuring this out. Without it, it's tough to help you out!
Just so you know, using 'final' on the map doesn't prevent you from modifying its contents with methods like .put(). It just means you can’t reassign the variable itself. So removing 'final' won't solve the issue.
This might sound simple, but did you check what exception is being thrown? Understanding the type of exception could really help narrow down the problem. And what's with adding the key's length to the value? Are both values integers?
From what I see, you're trying to modify the map while iterating through it. This can often lead to exceptions. Try going through the exception message and see if that helps clarify things!
Thanks for the tip! I'll check the exception message and get back to you.
Exactly, just changing values should be fine, so look for other issues!