protected synchronized Message receiveMessage() throws IOException { if (messageBuffer.size() > 0) { Message m = (Message) messageBuffer.get(0); messageBuffer.remove(0); return m; } try { InetSocketAddress remoteAddress = (InetSocketAddress) channel.receive(receiveBuffer); if (remoteAddress != null) { int len = receiveBuffer.position(); receiveBuffer.rewind(); receiveBuffer.get(buf, 0, len); try { IP address = IP.fromInetAddress(remoteAddress.getAddress()); int port = remoteAddress.getPort(); extractor.appendData(buf, 0, len, new SocketDescriptor(address, port)); receiveBuffer.clear(); extractor.updateAvailableMessages(); return extractor.nextMessage(); } catch (EOFException exc) { exc.printStackTrace(); System.err.println(buf.length + ", " + len); } catch (InvocationTargetException exc) { exc.printStackTrace(); } catch (IllegalAccessException exc) { exc.printStackTrace(); } catch (InstantiationException exc) { exc.printStackTrace(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (InvalidCompressionMethodException e) { e.printStackTrace(); } } } catch (ClosedChannelException exc) { if (isKeepAlive()) { throw exc; } } return null; }
public static void main(String[] args) { // Obtain the class object if we know the name of the class Class rental = RentCar.class; try { // get the absolute name of the class String rentalClassPackage = rental.getName(); System.out.println("Class Name is: " + rentalClassPackage); // get the simple name of the class (without package info) String rentalClassNoPackage = rental.getSimpleName(); System.out.println("Class Name without package is: " + rentalClassNoPackage); // get the package name of the class Package rentalPackage = rental.getPackage(); System.out.println("Package Name is: " + rentalPackage); // get all the constructors of the class Constructor[] constructors = rental.getConstructors(); System.out.println("Constructors are: " + Arrays.toString(constructors)); // get constructor with specific argument Constructor constructor = rental.getConstructor(Integer.TYPE); // initializing an object of the RentCar class RentCar rent = (RentCar) constructor.newInstance(455); // get all methods of the class including declared methods of // superclasses // in that case, superclass of RentCar is the class java.lang.Object Method[] allmethods = rental.getMethods(); System.out.println("Methods are: " + Arrays.toString(allmethods)); for (Method method : allmethods) { System.out.println("method = " + method.getName()); } // get all methods declared in the class // but excludes inherited methods. Method[] declaredMethods = rental.getDeclaredMethods(); System.out.println("Declared Methods are: " + Arrays.toString(declaredMethods)); for (Method dmethod : declaredMethods) { System.out.println("method = " + dmethod.getName()); } // get method with specific name and parameters Method oneMethod = rental.getMethod("computeRentalCost", new Class[] {Integer.TYPE}); System.out.println("Method is: " + oneMethod); // call computeRentalCost method with parameter int oneMethod.invoke(rent, 4); // get all the parameters of computeRentalCost Class[] parameterTypes = oneMethod.getParameterTypes(); System.out.println( "Parameter types of computeRentalCost() are: " + Arrays.toString(parameterTypes)); // get the return type of computeRentalCost Class returnType = oneMethod.getReturnType(); System.out.println("Return type is: " + returnType); // gets all the public member fields of the class RentCar Field[] fields = rental.getFields(); System.out.println("Public Fields are: "); for (Field oneField : fields) { // get public field name Field field = rental.getField(oneField.getName()); String fieldname = field.getName(); System.out.println("Fieldname is: " + fieldname); // get public field type Object fieldType = field.getType(); System.out.println("Type of field " + fieldname + " is: " + fieldType); // get public field value Object value = field.get(rent); System.out.println("Value of field " + fieldname + " is: " + value); } // How to access private member fields of the class // getDeclaredField() returns the private field Field privateField = RentCar.class.getDeclaredField("type"); String name = privateField.getName(); System.out.println("One private Fieldname is: " + name); // makes this private field instance accessible // for reflection use only, not normal code privateField.setAccessible(true); // get the value of this private field String fieldValue = (String) privateField.get(rent); System.out.println("fieldValue = " + fieldValue); } catch (NoSuchFieldException e) { e.printStackTrace(); } catch (NoSuchMethodException e) { e.printStackTrace(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InstantiationException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } }