Java boolean array with one element

Question

So I've come accross this bit of code while scavaging through org.eclipse.ui.internal.Workbench:

        final boolean[] initOK = new boolean[1];

        if (getSplash() != null) {

            final boolean[] initDone = new boolean[] { false };
            final Throwable[] error = new Throwable[1];
            Thread initThread = new Thread() {
                /*
                 * (non-Javadoc)
                 * 
                 * @see java.lang.Thread#run()
                 */
                public void run() {
                    try {
                        // declare us to be a startup thread so that our
                        // syncs will be executed
                        UISynchronizer.startupThread.set(Boolean.TRUE);
                        initOK[0] = Workbench.this.init();
                    } catch (Throwable e) {
                        error[0] = e;
                    } finally {
                        initDone[0] = true;
                        display.wake();
                    }
                }
            };
            initThread.start();

          ..............
       }

What's the purpose of creating arrays with just one element? Is it faster? I'm definitly missing something here.

Answer 1

The advantage of using this approach is that the arrays cannot be modified (because they are final), however, their content can be changed.

A useful example is that you can use these arrays and modify their first entry in anonymous inner classes without having to make them (static) fields.

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As stated in the comments above, another use-case is that this array can be used to pass it to a method expecting an array type.