我们可以通过反射,获取对应的运行时类中所有的属性、方法、构造器、父类、接口、父类的泛型、包、注解、异常等。。。。
典型代码:
@Test public void test1(){ Class clazz = Person.class; //获取属性结构 //getFields():获取当前运行时类及其父类中声明为public访问权限的属性 Field[] fields = clazz.getFields(); for(Field f : fields){ System.out.println(f); } System.out.println(); //getDeclaredFields():获取当前运行时类中声明的所属性。(不包含父类中声明的属性 Field[] declaredFields = clazz.getDeclaredFields(); for(Field f : declaredFields){ System.out.println(f); } } @Test public void test1(){ Class clazz = Person.class; //getMethods():获取当前运行时类及其所父类中声明为public权限的方法 Method[] methods = clazz.getMethods(); for(Method m : methods){ System.out.println(m); } System.out.println(); //getDeclaredMethods():获取当前运行时类中声明的所方法。(不包含父类中声明的方法 Method[] declaredMethods = clazz.getDeclaredMethods(); for(Method m : declaredMethods){ System.out.println(m); } } /* 获取构造器结构 */ @Test public void test1(){ Class clazz = Person.class; //getConstructors():获取当前运行时类中声明为public的构造器 Constructor[] constructors = clazz.getConstructors(); for(Constructor c : constructors){ System.out.println(c); } System.out.println(); //getDeclaredConstructors():获取当前运行时类中声明的所的构造器 Constructor[] declaredConstructors = clazz.getDeclaredConstructors(); for(Constructor c : declaredConstructors){ System.out.println(c); } } /* 获取运行时类的父类 */ @Test public void test2(){ Class clazz = Person.class; Class superclass = clazz.getSuperclass(); System.out.println(superclass); } /* 获取运行时类的带泛型的父类 */ @Test public void test3(){ Class clazz = Person.class; Type genericSuperclass = clazz.getGenericSuperclass(); System.out.println(genericSuperclass); } /* 获取运行时类的带泛型的父类的泛型 代码:逻辑性代码 vs 功能性代码 */ @Test public void test4(){ Class clazz = Person.class; Type genericSuperclass = clazz.getGenericSuperclass(); ParameterizedType paramType = (ParameterizedType) genericSuperclass; //获取泛型类型 Type[] actualTypeArguments = paramType.getActualTypeArguments(); // System.out.println(actualTypeArguments[0].getTypeName()); System.out.println(((Class)actualTypeArguments[0]).getName()); } /* 获取运行时类实现的接口 */ @Test public void test5(){ Class clazz = Person.class; Class[] interfaces = clazz.getInterfaces(); for(Class c : interfaces){ System.out.println(c); } System.out.println(); //获取运行时类的父类实现的接口 Class[] interfaces1 = clazz.getSuperclass().getInterfaces(); for(Class c : interfaces1){ System.out.println(c); } } /* 获取运行时类所在的包 */ @Test public void test6(){ Class clazz = Person.class; Package pack = clazz.getPackage(); System.out.println(pack); } /* 获取运行时类声明的注解 */ @Test public void test7(){ Class clazz = Person.class; Annotation[] annotations = clazz.getAnnotations(); for(Annotation annos : annotations){ System.out.println(annos); } }