How do I handle exceptions in Java Streams API?

How do I handle exceptions in Java Streams API?

In Java Streams API, you can handle exceptions by using a try-catch block within a lambda expression. However, since lambda expressions cannot throw checked exceptions directly, you might need to create a utility method to wrap your code.

Can you show me an example of that?

Sure! Here's a simple example:

List<String> list = Arrays.asList("1", "2", "a", "3");

List<Integer> result = list.stream()
    .map(s -> {
        try {
            return Integer.parseInt(s);
        } catch (NumberFormatException e) {
            return null; // Handle the exception
        }
    })
    .filter(Objects::nonNull)
    .collect(Collectors.toList());

What if I want to log the exception instead of returning null?

You can log the exception using a logging framework like SLF4J or simply print the stack trace. Here's how you can modify the example:

.map(s -> {
    try {
        return Integer.parseInt(s);
    } catch (NumberFormatException e) {
        e.printStackTrace(); // Log the exception
        return null;
    }
})