定义Student 类：包含：姓名和年龄等属性，有参和无参构造方法，输出所有信息的方法
1.使用多种方法生成一个Student类的Class对象 2.使用Class类获取Student类的结构信息并输出 3.通过有参(无参)构造方法动态创建Student类的对象 4.使用反射修改和查询Student类的姓名属性 5.使用反射动态执行Student类输出信息的方法
代码：
Student类
package 敲代码; //定义Student 类，包含：姓名和年龄等属性，有参和无参构造方法，输出所有信息的方法 public class Student { private String name; private int age; private String sex; @Override public String toString() { return "Student [name=" + name + ", age=" + age + ", sex=" + sex + "]"; } public Student(){} public Student(String name,int age,String sex){ this.name=name; this.age=age; this.sex=sex; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public void eat(){ System.out.println("eat apple!"); } private void run(){ System.out.println("run and listen to music!"); } public static void play(){ System.out.println("play game"); } }测试类：
package 敲代码; import java.lang.reflect.Constructor; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; public class Test { public static void main(String[] args) { //1.获取类对象 //first Student student=new Student(); Class clazz=student.getClass(); System.out.println(clazz.hashCode()); //second Class clazz2=Student.class; System.out.println(clazz2.hashCode()); //third try { Class clazz3=Class.forName("敲代码.Student"); System.out.println(clazz3.hashCode()); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } //2.使用Class类获取Student类的结构信息并输出 try { //构造方法 Constructor[] constructors=clazz.getDeclaredConstructors(); for (Constructor constructor2 : constructors) { System.out.println(constructor2); } //获取方法对象 Method[] methods=clazz.getDeclaredMethods(); for (Method method : methods) { System.out.println(method); } //获取属性 Field[] fields=clazz.getDeclaredFields(); for (Field field : fields) { System.out.println(field); } } catch (SecurityException e) { // TODO Auto-generated catch block e.printStackTrace(); } //3.通过有参(无参)构造方法动态创建Student类的对象 try { Constructor<Student> constructor=clazz2.getConstructor(String.class,int.class,String.class); Student student2=constructor.newInstance("张三",18,"张三"); System.out.println(student2); //4.使用反射修改和查询Student类的姓名属性 student2.setName("李四"); System.out.println(student2.getName()); //5.使用反射动态执行Student类输出信息的方法 Method method=clazz.getMethod("eat", null); method.invoke(student, null); } catch (NoSuchMethodException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SecurityException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InstantiationException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalAccessException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalArgumentException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InvocationTargetException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }运行结果：
