java反射之invoke详解（java反射之invoke详解）.docVIP

java反射之invoke详解（java反射之invoke详解） * * what is the main difference between the newInstance () method and the new keyword, except that one is the method and the other is the keyword? * they differ in the way objects are created, the former uses class loading mechanisms, and the latter creates a new class. * then why are there two ways to create objects? This is mainly concerned with software design ideas such as scalability, extensibility, and reusability. * when we create a class using the keyword new, this class can not be loaded. But when using the newInstance () method, * you must guarantee: 1, this class has been loaded; 2, this class is already connected. * newInstance () actually decomposes new into two steps, that is, first call the Class loading method, load a class, and then instantiate. * the benefits of such step-by-step measures are obvious. We can get better flexibility when we call classs static loading method, forName, * provides a means of decoupling (reducing coupling). * finally, the simplest description is used to distinguish between the new keyword and the newInstance () method: * newInstance: weak type. Poor efficiency。 Can only call the no argument structure. * new: strongly typed. Relatively efficient. Any public constructs can be called. Package * invoke; Import java.lang.reflect.InvocationTargetException; Import java.lang.reflect.Method; Import java.lang.reflect.Field; Public, class, testInvoke { Public, void, work () { System.out.println (-); } Public, testInvoke, work (String, a, Integer, b) { System.out.println (a + B); Return this; } Public, void, work (Integer, B, int, c) { System.out.println (B + C); } Public, static, void, main (String[], args), throws, SecurityException, NoSuchMethodException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException{ Class clazz = testInvoke.class; //Class clazz = Class.forName (invoke.testInvoke); //testInvoke, tinvoke = new, testInvoke (), Class, clazz =