this.getClass().getName() //当前Class名字 Thread.currentThread().getStackTrace()[1].getMethodName()); //当前方法名
Field[] fields = objClass.getFields();
for (Field field : fields) {
System.out.println(field.getName());
}
注意：只能去除 public变量
JAVA反射调用方法的步骤有三步
得到要调用类的class 得到要调用的类中的方法(Method) 方法调用(invoke)
Class<?> objClass = a.getClass();
Method[] methods = objClass.getDeclaredMethods();
for (Method method : methods) {
System.out.println(method);
}
package cn.netkiller.reflect;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
public class Member {
public 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;
}
@Override
public String toString() {
return "ClassA [name=" + name + ", age=" + age + "]";
}
public Member() {
// TODO Auto-generated constructor stub
}
public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, NoSuchMethodException, SecurityException, IllegalArgumentException, InvocationTargetException {
Class<?> cls = Class.forName("cn.netkiller.reflect.Member");
Object member = cls.newInstance();
Method setMethod = cls.getDeclaredMethod("setAge", int.class);
setMethod.invoke(member, 15);
Method getMethod = cls.getDeclaredMethod("getAge");
System.out.println(getMethod.invoke(member));
}
}
下面做一个稍微复杂点的例子，ClassB继承ClassA，取出ClassA的成员变量赋值到ClassA。
package cn.netkiller.reflect;
public class ClassA {
public 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;
}
public ClassA() {
// TODO Auto-generated constructor stub
}
@Override
public String toString() {
return "ClassA [name=" + name + ", age=" + age + "]";
}
}
package cn.netkiller.reflect;
public class ClassB extends ClassA{
public ClassB() {
// TODO Auto-generated constructor stub
}
private String address;
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "ClassB [address=" + address + "]";
}
}
package cn.netkiller.reflect;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
public class ReflectionTest {
public ReflectionTest() {
// TODO Auto-generated constructor stub
}
public void testSetMethod() throws NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, InstantiationException {
// ClassA a = new ClassA();
ClassB b = new ClassB();
b.setAddress("Shenzhen");
Class<ClassA> classA = ClassA.class;
ClassA a = classA.newInstance();
a.setName("Neo");
a.setAge(30);
System.out.println(classA.getDeclaredMethod("getAge").invoke(a));
Method m = classA.getDeclaredMethod("setAge", int.class);
m.setAccessible(true); // 因为写成private 所以这里必须设置
m.invoke(b, 26);
System.out.println(a.toString());
System.out.println(b.toString());
System.out.println(b.getName());
System.out.println(b.getAge());
}
public static void main(String[] args) throws InvocationTargetException {
ReflectionTest rt = new ReflectionTest();
try {
rt.testSetMethod();
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SecurityException 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 (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
set 方法
System.out.println(classA.getDeclaredMethod("getAge").invoke(a));
get 方法
Method m = classA.getDeclaredMethod("setAge", int.class);
m.setAccessible(true); //因为写成private 所以这里必须设置
m.invoke(b, 26);
Class cls = Class.forName("cn.netkiller.reflect.Student");
Method setMethod = cls.getDeclaredMethod("setAge",int.class);
setMethod.invoke(cls.newInstance(), 15);
static 方法调用时，不必得实例化对象
Class cls = Class.forName("cn.netkiller.reflect.Student");
Method staticMethod = cls.getDeclaredMethod("setAge",int.class);
staticMethod.invoke(cls,20); //这里不需要newInstance
原文出处：Netkiller 系列 手札
本文作者：陈景峯
转载请与作者联系，同时请务必标明文章原始出处和作者信息及本声明。
