long milliseconds;
int seconds = (milliseconds/1000)%60;
int minutes = (milliseconds/60000)%60;

int hours = (milliseconds/3600000)%24;
int days = milliseconds/(24*60*60*1000);

의외로 많이 써서..

산수는 의외로 귀찮다구..

java 의 enum은 컴파일러가 지원하는 primitive 타입이 아니라 컴파일러가 클래스로 변환시킨다.
Enum 클래스를 상속받은 static final class로서, 내부 요소들은 해당 클래스의 인스턴스를 가진다.

public class EnumType {
    public enum Editor {A1, A2};
    public static void main(String[] args) {
        System.out.println(Editor.A1);
    }
}

jad로 변환시키니, 다음과 같이 나왔다.

// Decompiled by Jad v1.5.8f. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://www.kpdus.com/jad.html
// Decompiler options: packimports(3) fieldsfirst nonlb space
// Source File Name:   EnumType.java

import java.io.PrintStream;

public class EnumType {
    public static final class Editor extends Enum {

        public static final Editor A1;
        public static final Editor A2;
        private static final Editor $VALUES[];

        public static final Editor[] values() {
            return (Editor[])$VALUES.clone();
        }

        public static Editor valueOf(String s) {
            return (Editor)Enum.valueOf(EnumType$Editor, s);
        }

        static  {
            A1 = new Editor("A1", 0);
            A2 = new Editor("A2", 1);
            $VALUES = (new Editor[] {
                A1, A2
            });
        }

        private Editor(String s, int i) {
            super(s, i);
        }
    }

    public EnumType() {
    }

    public static void main(String args[]) {
        System.out.println(Editor.A1);
    }
}

import static java.lang.Math.*;
import static a.StaticImportTest.*;
public class StaticImport {
    public static void main(String[] args) {
        System.out.println(print());
    }
}

주의할 점은 import static이라는 점과, 항상 클래스뒤에 필드, 메소드를 의미한다는 의미로 해석해야한다는 것이다.

import static java.lang.Math.*;

이 문장은 Math 클래스의 static 필드, 메소드를 바로 호출 할 수 있다는 의미이다.

자바 5.0의 Enum, Annotation Test Code이다.

실행결과는 따로 적지 않았다. 대충 만든거라, 약간 어설플 수도 있다.

import java.lang.annotation.*;
import java.lang.reflect.*;

@Retention(java.lang.annotation.RetentionPolicy.RUNTIME) @interface debug {
    boolean devbuild() default false;
    int counter();
}

@Retention(RetentionPolicy.RUNTIME)
@interface Java {
    String value();
}

@Retention(RetentionPolicy.RUNTIME)
@interface  ID {
    String value();
}

@Retention(RetentionPolicy.RUNTIME)
@interface Desc {
    String value();
}

@ID("1")
public class MetaTest {

    @Java("123712831783")
    public String a;

    /*
    public enum Type {
        E1("aa"), E2("bb");
        private final String value;
        Type(String value) { this.value = value; }
        public String value() { return value; }
    }
    public Type xType = Type.E1;
    */
    public enum DescEnum {  X1,  X2 };
    public DescEnum de = DescEnum.X1;

    public void de(DescEnum m) {
        if (DescEnum.X1.equals(m)) {
            System.out.println("changed X1");
        } else {
            System.out.println("changed X2");
        }
    }
    /*final boolean production = true;
    @debug(devbuild = production, counter=1) public void testMethod() {}

    public MetaTest() {
        System.out.println(this);
    }*/

    public static void main(String[] args) {
        MetaTest mt = new MetaTest();
        ///////////////////////////////////////////////////////////////
        // de 필드에 enum element의 특정값 넣기.?
        ///////////////////////////////////////////////////////////////

        try {
            Field field = mt.getClass().getField("de");
            System.out.println(field.getType());
            Class cls = field.getType();
            if (cls.isEnum()) {
                System.out.println("c");
            }
            Method method = cls.getMethod("valueOf", String.class);
            Object o = method.invoke(cls, new Object[] { "X2" });
            System.out.println("name : f.getName() : " + o);
            field.set(mt, o);
            System.out.println("result : " + mt.de);

            //------------------------------------------------------
            Method method2 = mt.getClass().getMethod("de", cls);
            Class cls2 = method2.getParameterTypes()[0];
            System.out.println("oj : " + cls2);
            if (cls2.isEnum()) {
                System.out.println("xx");
                Method mtd = cls2.getMethod("valueOf", String.class);
                Object o2 = mtd.invoke(cls2, new Object[] { "X1" });
                System.out.println("o : " + o2);
                method2.invoke(mt, o2);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
        ///////////////////////////////////////////////////////////////
        // 
        ///////////////////////////////////////////////////////////////

        /*
        ///////////////////////////////////////////////////////////////
        //  de 필드를 통해서 해당 값이 어떤것인지 알아오기.
        ///////////////////////////////////////////////////////////////

        try {
            Field field = mt.getClass().getField("de");
            System.out.println(field.getType());

            Class cls = field.getType();
            Field f = cls.getField("X1");
            Annotation a = f.getAnnotation(Desc.class);
            Method[] methods = a.getClass().getMethods();

            System.out.println(a);

            for (Method method : methods) {
                if (method.getName().equals("value")) {
                    System.out.println("**************find************");
                    try {
                        Object val = method.invoke(a, new Object[0]);
                        System.out.println("value: " + val);
                    } catch (Exception ex) {
                        ex.printStackTrace();
                    }
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }*/
        ///////////////////////////////////////////////////////////////
        //
        ///////////////////////////////////////////////////////////////

        /*try {
            Annotation[] a =
                mt.getClass().getMethod("testMethod").getAnnotations();
            for (int i = 0 ; i < a.length ; i++) {
                System.out.println("a[" + i + "]" + a[i]);
            }

        } catch (NoSuchMethodException e) {
            System.out.println(e);
        }
        String id = "1";
        System.out.println(id == "" ? "" : "2");

        Annotation ab = mt.getClass().getAnnotation(ID.class);
        System.out.println(ab);
        System.out.println("11");
        Field[] f = mt.getClass().getFields();
        System.out.println("22");
        Annotation a = f[0].getAnnotation(Java.class);
        Method[] methods = a.getClass().getMethods();
        System.out.println("num : " + methods.length);

        for (Method i : methods) {Type
            System.out.println("method = " + i.getName());
            //System.out.println("methods : " + i);

            if (i.getName().equals("value")) {
                System.out.println("**************find************");
                try {
                    Object val = i.invoke(a, new Object[0]);
                    System.out.println("value: " + val);
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        }
        System.out.println(a.toString()) ;
        System.out.println(a.value());

        Package p = mt.getClass().getPackage();
        System.out.println("aaa : " + p);
        try {
            Field field = mt.getClass().getField("a");
            System.out.println(field.getType());
            if (field.getType() == String.class) {
                System.out.println("equals to String");
            }

        } catch (Exception e) {
            e.printStackTrace();
        } */

    }
}

자바 5.0의 Annotation에 대한 샘플 예제를 만들어 보았다.

import java.lang.annotation.*;
import java.lang.reflect.*;
import java.util.*;

@Retention(RetentionPolicy.RUNTIME)
@interface Title {
    String value();
}
public class AnnotationTest {

    public enum DescEnum {  @Title("1") X1,  X2 , X3 };
    public static EnumSet<DescEnum> de = EnumSet.of(DescEnum.X1, DescEnum.X2);

    public static void main(String[] args) {
        AnnotationTest mt = new AnnotationTest();
        ///////////////////////////////////////////////////////////////
        // EnumSet
        ///////////////////////////////////////////////////////////////

        try {
            Field field = mt.getClass().getField("de");
            System.out.println(field.getGenericType()) ;
            ParameterizedType tv = (ParameterizedType) field.getGenericType();
            System.out.println(tv);
            System.out.println("rawtype : " + tv.getRawType());
            System.out.println("getOwnerType : " + tv.getOwnerType());
            System.out.println("getReal : " + tv.getActualTypeArguments());

            for (Type t : tv.getActualTypeArguments()) {
                System.out.println("t : " + t);
                //System.out.println("class name: " + c.getName());
                Field[] enumFields = ((Class)t).getFields();
                for (Field f : enumFields) {
                    System.out.println("enum element name : " + f.getName());
                }
            }

            Iterator iter = de.iterator();
            while(iter.hasNext()) {
                System.out.println(iter.next());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

실행결과

$ java AnnotationTest
java.util.EnumSet<AnnotationTest$DescEnum>
java.util.EnumSet<AnnotationTest$DescEnum>
rawtype : class java.util.EnumSet
getOwnerType : null
getReal : [Ljava.lang.reflect.Type;@66848c
t : class AnnotationTest$DescEnum
enum element name : X1
enum element name : X2
enum element name : X3
X1
X2

▣ RMI(Remote Method Invocation)
   - 분산 시스템 구축시 Socket 방식을 이용하는 것보다 간결하고 신속함
   - RPC(Remote Procedure Call) : 원격지의 함수 호출, C 언어에서 사용
   - CORBA의 분산 객체 시스템과 비슷(이기종 간의 분산 처리 구축, 코바서버를 2중으로 구축시 모든 서버에서 트랜잭션이 안정적으로 진행이 안됨)
   - 원리
                       Client Area ↓                ↓Server Area 
     -----------------------------------------------------------------------------------------
     Local System --> Class --> Stub --> NETWORK --> Stub --> Skeleton --> Class Remote System
                   결과전송 <-- Stub <-- NETWORK <----------- Skeleton <-- 비지니스 로직 처리                

1. RMI 프로그래밍 순서도
   ① 원격 인터페이스 정의
   ② 원격 객체 구현
   ③ javac 컴파일 - 원격 객체 클래스
   ④ rmic - Stub, Skeleton class 생성
   ⑤ 로컬 객체 클래스 제작  
   ⑤ RMI 등록 서버 실행
   ⑥ 클라이언트 접속

2. UnicastRemoteObject 의 상속 구조

     public abstract class RemoteObject extends Object implements Remote, Serializable
     --> java.lang.Object 클래스의 hashCode(), equals(), toString() 메소드를 구현해서 갖고 있는 클래스
     ↑
     public abstract class RemoteServer extends RemoteObject
     --> 원격지 메소드 참조에 대한 구현에 대한 FrameWork을 갖고 있는 최상위 클래스
     ↑
     public class UnicastRemoteObject extends RemoteServer
     -->  tcp 상에서 object reference를 참조할 수 있도록 지원해 주는 클래스

3. Echo 예제 실습
--------------------------------------------------------------------------
구분  CLIENT SIDE SERVER SIDE
--------------------------------------------------------------------------
Interface            Echo.class  Echo.class

Remote Object   EchoImpl.class

Proxy  EchoImpl_Stub.class EchoImpl_Stub/Skel.class

Run Class            EchoClient.class EchoServer.class
--------------------------------------------------------------------------
실행 순서
1. rmic EchoImp
2. start rmiregistry   <-- C:\Program Files\Oracle\jre\1.1.7\bin; 경로가 PATH에 있으면 제거하고 시스템 재 시작합니다.
3. java EchoServer
4. java EchoClient nulunggi

------------------------ e.bat ------------------------
rmic EchoImpl
start rmiregistry
rem ---------
rem 서버 작동
rem ---------
java EchoServer

1/4-------------------------- Echo.java --------------------------
import java.rmi.RemoteException;

import java.rmi.Remote;

public interface Echo extends Remote{
  public String sayEcho(String name) throws RemoteException;
}

2/4-------------------------- EchoImpl.java --------------------------
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class EchoImpl extends UnicastRemoteObject implements Echo{
 String message;

 public EchoImpl() throws RemoteException{}

 public EchoImpl(String message) throws RemoteException{
  this.message = message;
 }

 public String sayEcho(String name){
  return "\n 엄기흥 강사 PC 로 부터 전송된 문자열 : " + message + " " + name + "님 \n";
 }
}
 

3/4-------------------------- EchoServer.java --------------------------
import java.rmi.Naming;

public class EchoServer{
  public static void main(String args[]){
    try{
      EchoImpl echoRef = new EchoImpl();
      Naming.bind("Echo",echoRef);
    }catch( java.rmi.AlreadyBoundException e){
      e.printStackTrace();  
    }catch(java.net.MalformedURLException e ){
      e.printStackTrace();
    }catch( java.rmi.RemoteException e){
      e.printStackTrace();   
    }
    System.out.println("--------------------------------");
    System.out.println("Echo RMI 서버가 작동 되었습니다.");
    System.out.println("--------------------------------");
  }
}

4/4-------------------------- EchoClient.java --------------------------
import java.rmi.Naming;
import java.rmi.*;
import java.net.*;

public class EchoClient{
 public static void main(String args[]){
  String url = "rmi://127.0.0.1/Echo";
                     //String url = "rmi://" + args[0] + "/Echo";

  Echo echoRef = null;
  try{
   echoRef = (Echo)Naming.lookup(url);

   System.out.println(echoRef.sayEcho(args[0]));
  }catch(RemoteException e){
   e.printStackTrace();
  }catch(MalformedURLException e){
   e.printStackTrace();
  }catch(NotBoundException e){
   e.printStackTrace();
  }
  
 }
}

4. RMI 서버 모듈의 분리 예제
--------------------------------------------------------------------------
구분  CLIENT SIDE        SERVER SIDE
--------------------------------------------------------------------------
Interface            Echo.class         Echo.class
                      EchoFactory.class           EchoFactory.class

Remote Object          EchoImpl.class
                                                  EchoFactoryImpl.class 

Proxy  EchoImpl_Stub.class        EchoImpl_Stub/Skel.class
                     EchoFactoryImpl_Stub.class   EchoFactoryImpl_Stub/Skel.class

Run Class            EchoFactoryClient.class      EchoFactoryServer.class
Start File           s.bat                        r.bat
--------------------------------------------------------------------------

실행 방법 : r.bat
rem ---------------------------------------
rem 파일 내용 : Echo 예제 배치파일 입니다.
rem 작성일 : 2002-01-01
rem 작성자 : 엄기흥
rem ---------------------------------------
rmic EchoImpl
rmic EchoFactoryImpl
start rmiregistry.exe
java EchoFactoryServer

1/6------------------------ Echo.java ------------------------
import java.rmi.RemoteException;

import java.rmi.Remote;

public interface Echo extends Remote{
  public String sayEcho(String name) throws RemoteException;
}

2/6------------------------ EchoImpl.java ------------------------
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class EchoImpl extends UnicastRemoteObject implements Echo{
 String message;

 public EchoImpl() throws RemoteException{}

 public EchoImpl(String message) throws RemoteException{
  this.message = message;
 }

 public String sayEcho(String name){
  return "\n " + message + " " + name + "님 \n";
 }
}

3/6------------------------ EchoFactory.java ------------------------
import java.rmi.RemoteException;
import java.rmi.Remote;

public interface EchoFactory extends Remote{
  public Echo getEcho(String greeting) throws RemoteException;
}

4/6------------------------ EchoFactoryImpl.java ------------------------
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class EchoFactoryImpl extends UnicastRemoteObject implements EchoFactory{
 
  public EchoFactoryImpl() throws RemoteException{}

  public Echo getEcho(String message) throws RemoteException{
    EchoImpl echoRef = new EchoImpl(message);
    return (Echo)echoRef;
  }

}

5/6------------------------ EchoFactoryServer.java ------------------------
import java.rmi.Naming;

public class EchoFactoryServer {
 public static void main(String args[]) throws Exception{
  EchoFactoryImpl factoryRef = new EchoFactoryImpl();

  Naming.rebind("EchoFactory",factoryRef);
  
  System.out.println("서버가 시작되었습니다.");
 }
}

6/6------------------------ EchoFactoryClient.java ------------------------
import java.rmi.Naming;
import java.rmi.*;
import java.net.*;

public class EchoFactoryClient{
  public static void main(String args[]){
   
 //String url = "rmi://127.0.0.1/EchoFactory";

 EchoFactory ref = null;

 try{
  if (args.length != 2){
                        System.out.println("파라미터가 잘못되었습니다.");
   System.out.println("사용법 : java EchoFactoryClient nulunggi 211.108.242.114");
   System.exit(1);
  }

  ref = (EchoFactory)Naming.lookup("rmi://" + args[1] + "/EchoFactory");

  Echo echoHello = ref.getEcho("수고하셨습니다.");
  Echo echoGood = ref.getEcho("2개월간 고생하셨습니다.");

  System.out.println(echoHello.sayEcho(args[0])); 
  System.out.println(echoGood.sayEcho(args[0])); 

 }catch(RemoteException e){
  e.printStackTrace();  
 }catch(MalformedURLException e){
  e.printStackTrace(); 
 }catch(NotBoundException e){
  e.printStackTrace(); 
 }

  }
}

▣ RMI + Thread를 이용하여 여러 컴퓨터에서 계산하기

------------------------ e.bat ------------------------
rmic EchoImpl
start rmiregistry
rem ---------
rem 서버 작동
rem ---------
java EchoServer

1. 서버쪽 수정 EchoImpl.java

1/4-------------------------- Echo.java --------------------------
import java.rmi.RemoteException;

import java.rmi.Remote;

public interface Echo extends Remote{
  public String sayEcho(String name) throws RemoteException;
}

2/4-------------------------- EchoImpl.java --------------------------
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class EchoImpl extends UnicastRemoteObject implements Echo{
 String message;

 public EchoImpl() throws RemoteException{}

 public EchoImpl(String message) throws RemoteException{
  this.message = message;
 }

 public String sayEcho(String name){

             int i=1;
             long hap=0;

             for(long q=1; q<=500000000; q++){
                       hap = hap + q;
             }
    return i + "번째 1부터 500,000,000까지의 합 : " + hap + "\n";

 }
}
 

3/4-------------------------- EchoServer.java --------------------------
import java.rmi.Naming;

public class EchoServer{
  public static void main(String args[]){
    try{
      EchoImpl echoRef = new EchoImpl();
      Naming.bind("Echo",echoRef);
    }catch( java.rmi.AlreadyBoundException e){
      e.printStackTrace();  
    }catch(java.net.MalformedURLException e ){
      e.printStackTrace();
    }catch( java.rmi.RemoteException e){
      e.printStackTrace();   
    }
    System.out.println("--------------------------------");
    System.out.println("Thread용 Echo RMI 서버가 작동 되었습니다.");
    System.out.println("--------------------------------");
  }
}

4/4-------------------------- EchoClient.java --------------------------
import java.rmi.Naming;
import java.rmi.*;
import java.net.*;

public class EchoClient{
 public static void main(String args[]){
  String url = "rmi://127.0.0.1/Echo";
                     //String url = "rmi://" + args[0] + "/Echo";

  Echo echoRef = null;
  try{
   echoRef = (Echo)Naming.lookup(url);

   System.out.println(echoRef.sayEcho(args[0]));
  }catch(RemoteException e){
   e.printStackTrace();
  }catch(MalformedURLException e){
   e.printStackTrace();
  }catch(NotBoundException e){
   e.printStackTrace();
  }
  
 }
}

2. 클라이언트쪽
------------------------ EchoClientThread.java -------------------
/***********************************
파일명:
작성자: 엄기흥
최종 수정일: 20020308-2102
파일 내용: 자바 수업 중에 테스트 한 파일
************************************/
import java.rmi.Naming;
import java.rmi.*;
import java.net.*;

public class EchoClientThread extends Thread{
 String ip=null;
 Echo echoRef = null;

 EchoClientThread(String ip){
     this.ip = ip;
 }

 public void run(){
  try{
   String url = "rmi://" + ip + "/Echo";
   echoRef = (Echo)Naming.lookup(url);
   System.out.println(echoRef.sayEcho("누룽지"));

  }catch(RemoteException e){
   e.printStackTrace();
  }catch(MalformedURLException e){
   e.printStackTrace();
  }catch(NotBoundException e){
   e.printStackTrace();
  }

 }

 public static void main(String args[]){
  EchoClientThread e67, e74, e76, e78, e98, e72, e69;
  

  e67 = new EchoClientThread("211.108.242.106");
  e74 = new EchoClientThread("211.108.242.107");
  e76 = new EchoClientThread("211.108.242.109");
  e78 = new EchoClientThread("211.108.242.110");
  e98 = new EchoClientThread("211.108.242.108");
  e72 = new EchoClientThread("211.108.242.112");
  e69 = new EchoClientThread("211.108.242.114");

  e67.start();
  e74.start();
  e76.start();
  e78.start();
  e98.start();
  e72.start();
  e69.start();
 }
}

------------------------ EchoClientThread1.java -------------------
/***********************************
파일명:
작성자: 엄기흥
최종 수정일: 20020308-2102
파일 내용: 자바 수업 중에 테스트 한 파일
************************************/
import java.rmi.Naming;
import java.rmi.*;
import java.net.*;

public class EchoClientThread1 extends Thread{
 String ip=null;
 Echo echoRef = null;
 
 EchoClientThread1(String ip){
     this.ip = ip;
 }

 public void run(){
  try{
   if(ip.equals("67")){
    String url = "rmi://211.108.242.114/Echo";
    echoRef = (Echo)Naming.lookup(url);
    System.out.println(echoRef.sayEcho("누룽지"));
   }else if(ip.equals("74")){
    String url = "rmi://211.108.242.106/Echo";
    echoRef = (Echo)Naming.lookup(url);
    System.out.println(echoRef.sayEcho("누룽지"));
   }else if(ip.equals("76")){
    String url = "rmi://211.108.242.107/Echo";
    echoRef = (Echo)Naming.lookup(url);
    System.out.println(echoRef.sayEcho("누룽지"));
   }else if(ip.equals("78")){
    String url = "rmi://211.108.242.109/Echo";
    echoRef = (Echo)Naming.lookup(url);
    System.out.println(echoRef.sayEcho("누룽지"));
   }else if(ip.equals("98")){
    String url = "rmi://211.108.242.110/Echo";
    echoRef = (Echo)Naming.lookup(url);
    System.out.println(echoRef.sayEcho("누룽지"));
   }else if(ip.equals("72")){
    String url = "rmi://211.108.242.111/Echo";
    echoRef = (Echo)Naming.lookup(url);
    System.out.println(echoRef.sayEcho("누룽지"));
   }else if(ip.equals("69")){
    String url = "rmi://211.108.242.112/Echo";
    echoRef = (Echo)Naming.lookup(url);
    System.out.println(echoRef.sayEcho("누룽지"));
   }

  }catch(RemoteException e){
   e.printStackTrace();
  }catch(MalformedURLException e){
   e.printStackTrace();
  }catch(NotBoundException e){
   e.printStackTrace();
  }

 }

 public static void main(String args[]){
  EchoClientThread1 e67, e74, e76, e78, e98, e72, e69;
  

  e67 = new EchoClientThread1("67");
  e74 = new EchoClientThread1("74");
  e76 = new EchoClientThread1("76");
  e78 = new EchoClientThread1("78");
  e98 = new EchoClientThread1("98");
  e72 = new EchoClientThread1("72");
  e69 = new EchoClientThread1("69");

  e67.start();
  e74.start();
  e76.start();
  e78.start();
  e98.start();
  e72.start();
  e69.start();
 }
}

인터냇에서 찾은 미국사람의 싸이트에서 수정을 하고, 올린 글임..

제대로 컴파일되게 했다..

시간을 이용하여, 파일을 만들고. 그 파일을 실시간으로 컴파일하는 샘플 예제이다.

import java.io.*;
import java.util.*;
import java.lang.reflect.*;
import com.sun.tools.javac.Main;

/**

 * author @knight

 */

public class MakeTodayClass {
  Date today = new Date();
  String todayMillis = Long.toString(today.getTime());
  String todayClass = "z_" + todayMillis;
  String todaySource = todayClass + ".java";

  public static void main (String args[]){
    MakeTodayClass mtc = new MakeTodayClass();
    mtc.createIt();
    if (mtc.compileIt()) {
       System.out.println("Running " + mtc.todayClass + ":\n\n");
       mtc.runIt();
       }
    else
       System.out.println(mtc.todaySource + " is bad.");
    }

  public void createIt() {
    try {
      FileWriter aWriter = new FileWriter(todaySource, true);
      aWriter.write("public class "+ todayClass + "{");
      aWriter.write(" public void print() {");
      aWriter.write(" System.out.println(\""+todayMillis+"\");");
      aWriter.write(" }}\n");
      aWriter.flush();
      aWriter.close();
      }
    catch(Exception e){
      e.printStackTrace();
      }
    }

  public boolean compileIt() {
      try {
        String [] source = { new String(todaySource)};
        com.sun.tools.javac.Main main = new com.sun.tools.javac.Main();
        main.compile(source);
      }  catch (Exception e) {
          e.printStackTrace();
          return false;
      }
    return true;
    }

  public void runIt() {
    try {
      Class params[] = {};
      Object paramsObj[] = {};
      Class thisClass = Class.forName(todayClass);
      Object iClass = thisClass.newInstance();
      Method thisMethod = thisClass.getDeclaredMethod("print", params);
      thisMethod.invoke(iClass, paramsObj);
      }
    catch (Exception e) {
      e.printStackTrace();
      }
    }
 }