从布尔方法捕获并重新抛出异常的确会返回false，但是不执行任何操作会导致该方法不返回

Question

I have a general query regarding the java programming language and how it deals with exceptions and methods returning boolean.

Please not that although the example below deals with Spring/Ldap/ActiveDirectory, my question is only about java and exceptions .

public boolean doAuthenticate(String userAndDomain, String password) {
        UsernamePasswordAuthenticationToken userToken = new UsernamePasswordAuthenticationToken(replaceBackSlashWithAtSign(userAndDomain), password);
        try {
            Authentication authentication = adAuthenticationProvider.authenticate(userToken);
            return authentication.isAuthenticated();
        } catch (BadCredentialsException e) {
            log.error("Authentication failed - wrong username\\password", e);
            throw new BadCredentialsException("Authentication failed - wrong username\\password", e);
        } catch (AuthenticationException e) {
            log.error("Authentication failed - AuthenticationException", e);
            throw new AuthenticationException("Authentication failed - AuthenticationException", e) { };
        }
    }

If any of BadCredentialsException or AuthenticationException is rethrown by the authenticate method, then the doAuthenticate method returns false .

However if for some reason another runtime exception is thrown by adAuthenticationProvider.authenticate() , then the method does not return false and does not return at all ...

I am just curious to know why that is...

edit :

 LdapAuthentifier authentifier = new LdapAuthentifierImpl();
 boolean didAuthenticate = authentifier.doAuthenticate(VALID_USER, INVALID_PASSWORD);

A System.out.println of didAuthenticate does show false if one of the two specified exceptions are thrown whereas another exception halts execution of the program and the System.out.println is never reached...

edit 2 :

public static void main(String[] args) {
 LdapAuthentifier authentifier = new LdapAuthentifierImpl();
 boolean didAuthenticate = authentifier.doAuthenticate(VALID_USER, INVALID_PASSWORD);
}

Answer 1

I understand what happened. Here is the explanation.

The exception I actually saw in the logs was BadCredentialsException but this exception is never thrown by adAuthenticationProvider.authenticate and therefore never rethrown by the below method .

What actually happened was that the authentication.isAuthenticated() was just returning false and I was passing this boolean value to the client code.

I am including the method again for clarity's sake:

 @Override
    public boolean doAuthenticate(String userAndDomain, String password) {
        UsernamePasswordAuthenticationToken userToken = new UsernamePasswordAuthenticationToken(replaceBackSlashWithAtSign(userAndDomain), password);
        try {
            Authentication authentication = adAuthenticationProvider.authenticate(userToken);
            return authentication.isAuthenticated();
        } catch (BadCredentialsException e) {
            log.error("Authentication failed - wrong username\\password", e);
            throw new BadCredentialsException("Authentication failed - wrong username\\password", e);
        } catch (AuthenticationException e) {
            log.error("Authentication failed - AuthenticationException", e);
            throw new AuthenticationException("Authentication failed - AuthenticationException", e) { };
        }
    }