How can I throw CHECKED exceptions from inside Java 8 streams?

Question

How can I throw CHECKED exceptions from inside Java 8 streams/lambdas?

In other words, I want to make code like this compile:

public List

        

Answer 1

Here is a different view or solution for the original problem. Here I show that we have an option to write a code that will process only a valid subset of values with an option to detect and handle caseses when the exception was thrown.

    @Test
    public void getClasses() {

        String[] classNames = {"java.lang.Object", "java.lang.Integer", "java.lang.Foo"};
        List classes =
                Stream.of(classNames)
                        .map(className -> {
                            try {
                                return Class.forName(className);
                            } catch (ClassNotFoundException e) {
                                // log the error
                                return null;
                            }
                        })
                        .filter(c -> c != null)
                        .collect(Collectors.toList());

        if (classes.size() != classNames.length) {
            // add your error handling here if needed or process only the resulting list
            System.out.println("Did not process all class names");
        }

        classes.forEach(System.out::println);
    }