자바(Java) Reflect 예제 동적 Method 호출

자바(Java) Reflect 예제 동적 Method 호출

 

ReflectMethod.java

 

001.package reflect;

002. 

003.public class ReflectMethod {

004.  

005.   //field

006.   public String field;

007.  

008.   //constructor

009.   public ReflectMethod() {}

010. 

011.   public ReflectMethod(String field) {

012.      this.field = field;

013.   }

014.  

015.   //method

016.   public String getField() {

017.      System.out.println("call field : " + this.field);

018.      return this.field;

019.   }

020.   public void methodA() {

021.      System.out.println("call method A");

022.   }

023.   public void methodB(String str) {

024.      System.out.println("call method B : " + str);

025.   }

026.   public String methodC() {

027.      System.out.println("call method C");

028.      return "method C";

029.   }

030.}

031. 

032.ReflectMain.java

033. 

034.package reflect;

035. 

036.import java.lang.reflect.Constructor;

037.import java.lang.reflect.Field;

038.import java.lang.reflect.InvocationTargetException;

039.import java.lang.reflect.Method;

040. 

041.public class ReflectMain {

042.   public static void main(String[] arguments) throws

043.                                         ClassNotFoundException,

044.                                         InstantiationException,

045.                                         IllegalAccessException,

046.                                         SecurityException,

047.                                         NoSuchMethodException,

048.                                         IllegalArgumentException,

049.                                         InvocationTargetException,

050.                                         NoSuchFieldException {

051.   

052.  /*

053.   * 원시형 클래스 타입

054.   * char : Character.TYPE

055.   * byte : Byte.TYPE

056.   * short : Short.TYPE

057.   * int : Integer.TYPE

058.   * long : Long.TYPE

059.   * float : Float.TYPE

060.   * double : Double.TYPE

061.   */

062.   

063.      //클래스 가져오기

064.      Class getClass1 = Class.forName("reflect.ReflectMethod");

065.      Class getClass2 = ReflectMethod.class;

066.      Class getClass3 = new ReflectMethod().getClass();

067.   

068.      //클래스 객체를 이용한 객체 생성

069. 

070.      //생성자에 인자가 없는 경우

071.      Object object1 = getClass1.newInstance();

072.      //생성자에 인자가 있을 경우

073.      Class[] constructorParamClass = new Class[] {String.class};

074.      Object[] constructorParamObject = new Object[] {"Reflect Test!!!"};

075.      Constructor constructor = getClass1.getConstructor(constructorParamClass);

076.      Object object2 = constructor.newInstance(constructorParamObject);

077. 

078.      //필드 값 가져오기

079.      Field field = getClass1.getField("field");

080.      Object fieldObject = field.get(object2);

081.   

082.      System.out.println(fieldObject);

083.   

084.      //메소드 호출

085.   

086.      //메소드에 인자가 없는 경우

087.      Method method1 = getClass1.getMethod("methodA");

088.      method1.invoke(object1);

089.      //메소드에 인자가 있을 경우

090.      Class[] methodParamClass = new Class[] {String.class};

091.      Object[] methodParamObject = new Object[] {"1 parameter"};

092.      Method method2 = getClass1.getMethod("methodB", methodParamClass);

093.      method2.invoke(object1, methodParamObject);

094.      //메소드에 리턴값이 있을 경우

095.      Method method3 = getClass1.getMethod("methodC");

096.      Object returnObject = method3.invoke(object1);

097.   

098.      System.out.println("methodC return value : " + returnObject);

099.   }

100.}

콘솔출력결과
Reflect Test!!!
call method A
call method B : 1 parameter
call method C
methodC return value : method C