about the implementation of SimpleIoProcessorPool

[Peng Lee]

      In my opinion,the line 176 [if (processorConstructor == null) ]
is redundant, because if processorConstructor is null, a
NullPointerException should be trowed previously. So, I think we
should remove the redundant code here.
 Of course, maybe there are any other things that i haven't knew
about, and who knows?

the version I talked about is Mina 2, and follow is the version infomation:

ste...@stefan:~/Mina/trunk$ svn info
Path: .
URL: http://svn.apache.org/repos/asf/mina/trunk
Repository Root: http://svn.apache.org/repos/asf
Repository UUID: 13f79535-47bb-0310-9956-ffa450edef68
Revision: 885194
Node Kind: directory
Schedule: normal
Last Changed Author: elecharny
Last Changed Rev: 884479
Last Changed Date: 2009-11-26 17:41:32 +0800 (四, 26 11月 2009)


@SuppressWarnings("unchecked")
    public SimpleIoProcessorPool(Class<? extends IoProcessor<T>> processorType,
            Executor executor, int size) {
        if (processorType == null) {
            throw new NullPointerException("processorType");
        }
        if (size <= 0) {
            throw new IllegalArgumentException("size: " + size
                    + " (expected: positive integer)");
        }

        if (executor == null) {
            this.executor = executor = Executors.newCachedThreadPool();
            this.createdExecutor = true;
        } else {
            this.executor = executor;
            this.createdExecutor = false;
        }

        pool = new IoProcessor[size];

        boolean success = false;
        Constructor<? extends IoProcessor<T>> processorConstructor = null;
        boolean usesExecutorArg = true;

        try {
            // We create at least one processor
            try {
                try {
                    processorConstructor = processorType
                            .getConstructor(ExecutorService.class);
                    pool[0] = processorConstructor.newInstance(executor);
                } catch (NoSuchMethodException e) {
                    // To the next step...
                }

                try {
                    processorConstructor = processorType
                            .getConstructor(Executor.class);
                    pool[0] = processorConstructor.newInstance(executor);
                } catch (NoSuchMethodException e) {
                    // To the next step...
                }

                try {
                    processorConstructor = processorType.getConstructor();
                    usesExecutorArg = false;
                    pool[0] = processorConstructor.newInstance();
                } catch (NoSuchMethodException e) {
                    // To the next step...
                }
            } catch (RuntimeException e) {
                throw e;
            } catch (Exception e) {
                throw new RuntimeIoException(
                        "Failed to create a new instance of "
                                + processorType.getName(), e);
            }

         // here ,  maybe itis redundant
            if (processorConstructor == null) {
                // Raise an exception if no proper constructor is found.
                throw new IllegalArgumentException(String
                        .valueOf(processorType)
                        + " must have a public constructor "
                        + "with one "
                        + ExecutorService.class.getSimpleName()
                        + " parameter, "
                        + "a public constructor with one "
                        + Executor.class.getSimpleName()
                        + " parameter or a public default constructor.");
            }

            // Constructor found now use it for all subsequent instantiations
            for (int i = 1; i < pool.length; i++) {
                try {
                    if (usesExecutorArg) {
                        pool[i] = processorConstructor.newInstance(executor);
                    } else {
                        pool[i] = processorConstructor.newInstance();
                    }
                } catch (Exception e) {
                    // Won't happen because it has been done previously
                }
            }
            success = true;
        } finally {
            if (!success) {
                dispose();
            }
        }
    }


Stefan Lee(李鹏)
Huazhong University of Science and Technology