RFR: 8322981: Fix 2 locations in JDI that throw IOException without using the "Caused by" exception

[Chris Plummer]

On Thu, 4 Jan 2024 06:56:37 GMT, David Holmes <dholmes at openjdk.org> wrote:

> Setting the cause is good, but do you not also want an informative message?

Not necessary.

public class Test {
    public static void main(String[] args) {
        try {
            try {
                throw new Throwable("hello");
            } catch (Throwable t) {
                throw new Throwable(t);
            }
        } catch (Throwable t) {
            t.printStackTrace(System.out);
        }
    }
}

produces:

java.lang.Throwable: java.lang.Throwable: hello
	at Test.main(Test.java:7)
Caused by: java.lang.Throwable: hello
	at Test.main(Test.java:5)

If I change the second throw to:

                throw new Throwable(t,"goodbye");

You get:

java.lang.Throwable: goodbye
	at Test.main(Test.java:7)
Caused by: java.lang.Throwable: hello
	at Test.main(Test.java:5)

So it appears that for the first line of the prinstStackTrace() output, it prints the exception name and then the message if there is one. If there is no message then it instead prints the cause exception name, and its message if it has one.

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PR Comment: https://git.openjdk.org/jdk/pull/17258#issuecomment-1877474604