package reflect;
public class Person {
private String name;
private int age;
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;
}
Person() {
}
private void Person(String name, int age) {
this.name = name;
this.age = age;
}
private String getInfo(String name, int age) {
return name+":"+String.valueOf(age)+"岁";
}
}
package reflect;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
//https://www.cnblogs.com/bbbing/p/11011424.html
//https://blog.csdn.net/ljphhj/article/details/12858767
//https://www.jianshu.com/p/9be58ee20dee
//https://www.cnblogs.com/jiangyi-uestc/p/5689771.html
public class App {
public static void main(String[] args) throws Exception {
//获取类的所有属性
reflect_callField();
//赋值类的属性
reflect_setField();
//获取类的构造方法
reflect_callConstructor();
//获取类的方法
reflect_callMethod();
//调用类的私有方法
reflect_setMethod() ;
}
/***
* 获取类的所有属性,包括私有属性
*
*/
public static void reflect_callField() throws Exception {
System.out.println("获取类的属性...");
Class<?> clz=Class.forName("reflect.Person");
Field[] fields = clz.getDeclaredFields();
for (Field field : fields) {
System.out.println(field.getName());
}
}
/***
* 设置类的属性值
*
*/
public static void reflect_setField() throws Exception {
System.out.println("设置类的属性值...");
Class<?> clz=Class.forName("reflect.Person");
Object obj = clz.newInstance();
Field field = clz.getDeclaredField("age");
field.setAccessible(true);
field.set(obj, 16);
System.out.println(field.getName()+","+field.get(obj));
}
/***
* 获取类的构造器
*
*/
public static void reflect_callConstructor() throws Exception {
System.out.println("获取类的构造器...");
Class<?> clz=Class.forName("reflect.Person");
Constructor[] constructors = clz.getDeclaredConstructors();
for (Constructor constructor : constructors) {
System.out.println(constructor);
}
}
/***
* 获取类的方法
*
*/
public static void reflect_callMethod() throws Exception {
System.out.println("获取类的方法...");
Class<?> clz=Class.forName("reflect.Person");
Method[] methods = clz.getDeclaredMethods();
for(Method method:methods) {
System.out.println(method);
}
}
/***
* 调用类的私有方法
*
*/
public static void reflect_setMethod() throws Exception {
System.out.println("调用类的方法...");
Class<?> clz=Class.forName("reflect.Person");
Object object = clz.newInstance();
// Constructor constructor=clz.getDeclaredConstructor(String.class, int.class);
// Object object=constructor.newInstance("Mike",20);
Method method=clz.getDeclaredMethod("getInfo", String.class,int.class);
method.setAccessible(true);
Object obj = method.invoke(object,new Object[]{"小明",30});
System.out.println(obj);
}
}
打印结果
获取类的属性...
name
age
设置类的属性值...
age,16
获取类的构造器...
reflect.Person()
获取类的方法...
public java.lang.String reflect.Person.getName()
public void reflect.Person.setName(java.lang.String)
private java.lang.String reflect.Person.getInfo(java.lang.String,int)
public int reflect.Person.getAge()
public void reflect.Person.setAge(int)
private void reflect.Person.Person(java.lang.String,int)
调用类的方法...
小明:30岁
