java反射+多线程+异常处理（Java reflection + multithreading + exception handling）.docVIP

java反射+多线程+异常处理（Java reflection + multithreading + exception handling） 1.Java reflection mechanism: accessing, detecting, and modifying functions describing the Java object itself through the Java object that has been loaded into the JVM (the Java object is already loaded and running). This information includes construction methods, methods, member variables, and so on. For example, you can get the return type of the method, the number and type of arguments of the method, or change the member variable values in the object, and so on. Ex: BJTU bjtu=new BJTU (); //Java is case sensitive, and BJTU is the instance of BJTU (instantiating a class to obtain an object) Class bjtuC=bjtu.getClass (); the getClass () method defined in the //object class returns an object Class of type bjtuC; uses the bjtuC object to access the BJTU object itself, and implements the reflection mechanism. Constructor[] (declaredConstructors=bjtuC.getDeclaredConstructors); / / get all the construction method of BJTU object class through the bjtuC object in an array of storage. Field[] (declareFields=bjtuC.getDeclaredFields); / / get the object of all member variables For (int i=0; ideclaredFields.length; i++) { Field field=declaredFields[i]; If (fieldType.equals (int.class)) / / if the type of the member variables for type int { Field.setInt (BJTU, 520); / / the member variable value to 520, implementation process of reverse control program (such as program variables initialized again) } The following is an example of Annotation. If (field.isAnnotationPresent (Schools_Annotation.class)) / / if the field annotation type is Schools_Annotation { Schools_Annotation sa=field.getAnnotation (Schools_Annotation.class); / / get the field corresponding to the instance of Schools_Annotation SA System.out.println (college is: +sa.describe ()); / / get the describe parameter value corresponding to the notes System.out.println (the data type is: +sa.type ()); } } Note: the method of construction is not necessa