package com.atguigu.java2;
import com.atguigu.java1.Person;
import org.junit.Test;
import java.lang.annotation.Annotation;
import java.lang.reflect.Constructor;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
/**
* @author
* @create 2022-05-05-16:10
*/
public class OtherTest {
/*
获取构造器结构
*/
@Test
public void test1(){
Class<Person> 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.getName());
}
System.out.println();
//getDeclaredConstructors():获取当前运行时类中声明的所有的构造器
Constructor[] declaredConstructors = clazz.getDeclaredConstructors();
for (Constructor c:declaredConstructors){
System.out.println(c.getName());
}
}
/*
获取运行时类的父类
*/
@Test
public void test2(){
Class<Person> clazz = Person.class;
Class<? super Person> superclass = clazz.getSuperclass();
System.out.println(superclass);
}
/*
获取运行时类带泛型的父类
*/
@Test
public void test3(){
Class<Person> clazz = Person.class;
Type genericSuperclass = clazz.getGenericSuperclass();
System.out.println(genericSuperclass);
}
/*
获取运行时类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<Person> clazz = Person.class;
Type genericSuperclass = clazz.getGenericSuperclass();
ParameterizedType paraType= (ParameterizedType) genericSuperclass;
//获取泛型类型
Type[] actualTypeArguments = paraType.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<Person> clazz = Person.class;
Class[] interfaces = clazz.getInterfaces();
for (Class c:interfaces){
System.out.println(c);
}
System.out.println();
//获得运行时类父类实现的接口
Class<? super Person> superclass = clazz.getSuperclass();
Class<?>[] interfaces1 = superclass.getInterfaces();
for (Class c:interfaces1){
System.out.println(c);
}
}
/*
获取运行时类所在的包
*/
@Test
public void test6(){
Class<Person> clazz = Person.class;
Package aPackage = clazz.getPackage();
System.out.println(aPackage);
}
/*
获取运行时类声明的注解
*/
@Test
public void test7(){
Class<Person> clazz = Person.class;
Annotation[] annotations = clazz.getAnnotations();
for (Annotation a:annotations){
System.out.println(a);
}
}
}
Person类构造：
package com.atguigu.java1;
/**
* @author
* @create 2022-05-05-14:36
*/
@MyAnnotation(value = "hi")
public class Person extends Creature<String> implements Comparable<String>, MyInterface {
private String name;
int age;
public int id;
public Person() {
}
@MyAnnotation(value = "abc")
private Person(String name) {
this.name = name;
}
Person(String name, int age) {
this.name = name;
this.age = age;
}
@MyAnnotation
private String show(String nation) {
System.out.println("我的国籍是" + nation);
return nation;
}
public String display(String interests, int age) throws NullPointerException, ClassCastException {
return interests + age;
}
@Override
public void info() {
System.out.println("我是一个人");
}
@Override
public int compareTo(String o) {
return 0;
}
}
package com.atguigu.java1;
/**
* @author
* @create 2022-05-05-14:39
*/
public interface MyInterface {
void info();
}
package com.atguigu.java1;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import static java.lang.annotation.ElementType.*;
/**
* @author
* @create 2022-05-05-14:46
*/
@Target({TYPE, FIELD, METHOD, PARAMETER, CONSTRUCTOR, LOCAL_VARIABLE})
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
String value() default "hello";
}
package com.atguigu.java1;
import java.io.Serializable;
/**
* @author
* @create 2022-05-05-14:37
*/
public class Creature<T> implements Serializable {
private char gender;
public double weight;
private void breath(){
System.out.println("生物呼吸");
}
public void eat(){
System.out.println("生物吃东西");
}
}
