package day18;import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Arrays;class Student{private int no;public String name;public Student() {System.out.println("无参构造");}public Student(int no, String name) {this.no = no;this.name = name;System.out.println("带参构造："+no+","+name);}public void f1() {System.out.println("无参无返回值得方法f1");}public String f2(String s,int n) {return "串"+s+":"+n;}
}
public class TestClass1 {public static void main(String[] args) throws Exception {// Class反射//运行 期  获得类中的信息//先获得 字节码文件的对象Class<?> c = Class.forName("day18.Student");
//        Class<Student> c = Student.class;
//        Class<? extends Student> c = new Student().getClass();//属性----------------------------------------------------------System.out.println("-------------------属性 ----------------------");
//        Field [] fs = c.getFields();//public Field [] fs = c.getDeclaredFields();//所有属性for(Field f: fs) {System.out.println(f.getName());System.out.println(f.getType());System.out.println(Modifier.toString(f.getModifiers()));}Field f1 = c.getDeclaredField("name");Object obj = c.newInstance();//调用构造f1.set(obj, "Tom");System.out.println(f1.get(obj));Field f2 = c.getDeclaredField("no");f2.setAccessible(true);//设置允许访问权限f2.set(obj, 11);System.out.println(f2.get(obj));//方法----------------------------------------------------------------System.out.println("------------------方法--------------------------");Method [] ms = c.getDeclaredMethods();for(Method m :ms) {System.out.println(m.getName());System.out.println(m.getReturnType());System.out.println(Arrays.toString(m.getParameterTypes()));}Method m1 = c.getDeclaredMethod("f1");m1.invoke(obj);Method m2 = c.getDeclaredMethod("f2", String.class,int.class);System.out.println(m2.invoke(obj, "hello",123));//构造--------------------------------------------------------------System.out.println("-------------------构造--------------------------------");Constructor<?> [] crs = c.getDeclaredConstructors();for(Constructor cr :crs) {System.out.println(cr.getName());System.out.println(Arrays.toString(cr.getParameterTypes()));}Constructor cr1 = c.getDeclaredConstructor();cr1.newInstance();Constructor cr2 = c.getDeclaredConstructor(int.class,String.class);cr2.newInstance(111,"郭靖");}}