Java에서 signal 처리 - JNI -

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Java에서 signal 처리 - JNI -

signal 핸들링은 (제 생각엔) Java 에선 뜨거운 감자 같습니다. 왜냐면, signal 핸들링은 OS 마다 다른데, 어떤 OS에서든 동작해야 하는 Java 입장에선 일반화된 Java API를 제공하기엔 바람직하지 않은 듯 합니다. 예를 들어 kill 명령어는 Unix 에서는 일반적이지만, Windows 에선 (제가 알기로는) kill 명령어가 없듯이 (즉, signal 를 해당 process 에게 줄수 있는 방법이 없듯이) java 에서 signal 핸들링은 결국 OS 종속적인 JNI 를 이용해 필요할 때 알아서 사용토록하고, Java 는 관여치 않는 듯 합니다. C 에서 signal 핸들링을 해 보셨고, 또, Java 의 JNI 를 해 보셨다면, 저처럼 어렵지 않게 다음과 같은 테스트를 해 볼 수 있을 겁니다. 첫번째 예제는 실행된 Java 프로그램에서 가능한 모든 종류의 signal 을 잡아보는 예제입니다. 기본개념은 JNI C 메소드를 호출해 signal 을 등록하고, C native 코드에서 signal 이 오면, Java 의 특정 메소드를 JNI callback 을 이용해 호출시켜 주는 구조입니다. javaservice:/home/guest/source/signal$ ls -alF total 12 drwxr-xr-x 3 java java 4096 Jan 1 23:21 ./ drwxrwxrwx 6 guest users 4096 Jan 1 23:21 ../ drwxr-xr-x 3 java java 4096 Jan 1 23:20 org/ javaservice:/home/guest/source/signal$ ls -alF org/jsn/signal/ total 12 drwxr-xr-x 2 java java 4096 Jan 1 23:36 ./ drwxr-xr-x 3 java java 4096 Jan 1 23:21 ../ -rw-r--r-- 1 java java 651 Jan 1 23:36 SignalTest.java javaservice:/home/guest/source/signal# cat org/jsn/signal/SignalTest.java package org.jsn.signal; public class SignalTest { public SignalTest() { for(int i=1;i<31;i++) signal(i, "handle"); System.out.println("signal listening"); } public void do_something(){ // infinite loop for(int i=0; true ; i++) { System.out.println("waiting..." + i); try{Thread.sleep(1000 * 10);}catch(Exception e){} } } public native synchronized void signal(int signum, String handles); /* This callback method will be called by native code*/ public void handle(int signum) { System.out.println("I have got signal : " + signum); if ( signum == 3 || signum == 9 || signum == 15 ) { System.out.println("gracefully exited, really?"); System.exit(0);// NOTE: this does NOT work; } } static { try{ System.loadLibrary("signalhandle"); }catch(Exception e){ e.printStackTrace(); } } public static void main(String[] args){ SignalTest test = new SignalTest(); test.do_something(); } } javaservice:/home/guest/source/signal$ javaservice:/home/guest/source/signal$ javac org/jsn/signal/SignalTest.java javaservice:/home/guest/source/signal$ ls -alF org/jsn/signal/ total 16 drwxr-xr-x 2 java java 4096 Jan 1 23:37 ./ drwxr-xr-x 3 java java 4096 Jan 1 23:21 ../ -rw-r--r-- 1 java java 1088 Jan 1 23:37 SignalTest.class -rw-r--r-- 1 java java 651 Jan 1 23:36 SignalTest.java javaservice:/home/guest/source/signal$ javah -jni org.jsn.signal.SignalTest javaservice:/home/guest/source/signal$ ls -alF total 16 drwxr-xr-x 3 java java 4096 Jan 1 23:38 ./ drwxrwxrwx 6 guest users 4096 Jan 1 23:21 ../ drwxr-xr-x 3 java java 4096 Jan 1 23:20 org/ -rw-r--r-- 1 java java 488 Jan 1 23:38 org_jsn_signal_SignalTest.h javaservice:/home/guest/source/signal# cat org_jsn_signal_SignalTest.h /* DO NOT EDIT THIS FILE - it is machine generated */ #include <jni.h> /* Header for class org_jsn_signal_SignalTest */ #ifndef _Included_org_jsn_signal_SignalTest #define _Included_org_jsn_signal_SignalTest #ifdef __cplusplus extern "C" { #endif /* * Class: org_jsn_signal_SignalTest * Method: signal * Signature: (ILjava/lang/String;)V */ JNIEXPORT void JNICALL Java_org_jsn_signal_SignalTest_signal (JNIEnv *, jobject, jint, jstring); #ifdef __cplusplus } #endif #endif javaservice:/home/guest/source/signal# (....... vi signalhandle.c ....... ) javaservice:/home/guest/source/signal# ls -alF total 48 4 drwxr-xr-x 3 java java 4096 Jan 2 01:38 ./ 4 drwxrwxrwx 6 guest users 4096 Jan 2 01:33 ../ 8 -rw-r--r-- 1 root root 4625 Jan 2 01:28 NativeStringUtil.c 4 -rw-r--r-- 1 root root 559 Jan 2 01:28 NativeStringUtil.h 4 -rw-r--r-- 1 root root 129 Jan 2 01:38 cc 4 drwxr-xr-x 3 java java 4096 Jan 1 23:20 org/ 4 -rw-r--r-- 1 java java 488 Jan 2 01:35 org_jsn_signal_SignalTest.h 4 -rw-r--r-- 1 java java 829 Jan 2 01:37 signalhandle.c javaservice:/home/guest/source/signal# javaservice:/home/guest/source/signal# cat signalhandle.c #include <signal.h> #include "org_jsn_signal_SignalTest.h" #include "NativeStringUtil.h" /* NOTE: global variable !! */ JNIEnv *g_env; jobject g_obj; jmethodID g_mid; void signal_handle(signum) int signum; { if ( g_mid == 0 ) return; (*g_env)->CallVoidMethod(g_env, g_obj, g_mid, signum); } /* * Class: org_jsn_signal_SignalTest * Method: signal * Signature: (ILjava/lang/String;)V */ JNIEXPORT void JNICALL Java_org_jsn_signal_SignalTest_signal (JNIEnv *env, jobject obj, jint signum, jstring handle_name) { jclass cls = (*env)->GetObjectClass(env, obj); char *method = jbyteArray2cstr( env, javaGetBytes(env, handle_name) ); jmethodID mid = (*env)->GetMethodID(env,cls, method, "(I)V"); if ( mid == 0 ) return; g_env = env; g_obj = obj; g_mid = mid; signal(signum, signal_handle); } javaservice:/home/guest/source/signal# cat cc #!/bin/sh gcc -shared -I/usr/java/include \ -I/usr/java/include/linux \ -o libsignalhandle.so signalhandle.c NativeStringUtil.c javaservice:/home/guest/source/signal# sh cc javaservice:/home/guest/source/signal# javaservice:/home/guest/source/signal# export LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH javaservice:/home/guest/source/signal# export CLASSPATH=.:$CLASSPATH javaservice:/home/guest/source/signal# javaservice:/home/guest/source/signal# java org.jsn.signal.SignalTest signal listening waiting...0 waiting...1 waiting...2 .... 이렇게 수행되고 있을 때, 다른 터미널에서 kill 명령어를 날려 봅니다. [Terminal B] javaservice:/root# ps -ef|grep java|grep root root 17102 15065 2 01:00 pts/4 00:00:00 /usr/java/bin/linux/native_threa root 17110 17102 0 01:00 pts/4 00:00:00 /usr/java/bin/linux/native_threa root 17111 17110 0 01:00 pts/4 00:00:00 /usr/java/bin/linux/native_threa root 17112 17110 0 01:00 pts/4 00:00:00 /usr/java/bin/linux/native_threa root 17115 15768 0 01:00 pts/3 00:00:00 grep java javaservice:/root# kill -2 17102 javaservice:/root# kill -3 17102 javaservice:/root# kill -15 17102 javaservice:/root# kill -10 17102 javaservice:/root# kill -9 17102 javaservice:/root# 결과는 다음과 같습니다. javaservice:/home/guest/source/signal# java org.jsn.signal.SignalTest signal listening waiting...0 waiting...1 waiting...2 I have got signal : 2 I have got signal : 3 gracefully exited, really? waiting...3 I have got signal : 15 gracefully exited, really? waiting...4 I have got signal : 10 waiting...5 Killed javaservice:/home/guest/source/signal# 이 프로그램은 Ctl-C 를 눌려도 종료되지 않습니다. signal 2 : SIGINT 가 잡히기 때문입니다. 오로지 다른 터미널 창에서 kill -9 를 날려야만 죽습니다. 주의할 점은 JNI의 callback 을 통해 수행되는 Java code 에서 System.exit() 을 날려도 JVM 이 exit 되지는 않습니다. NOTE: signal 번호는 아래의 첨부 A 를 참조하세요. 따라서, 이와 같은 signal 처리는 단지 자바프로그램에서 process 의 signal 을 받아 무언가를 하도록 할 때 사용될 수 있을 뿐이며, "gracefully exiting" 을 이처럼 JNI의 callback 을 이용해 구현할 수는 없는 듯 합니다. 즉, Ctl-C 를 누른다거나, kill -9 를 제외한 kill -3 (SIGQUIT), kill -15(SIGTERM) 를 잡아채어 미진한 종료작업을 수행한 수 JVM이 내려가도록 하려면 뭔가 다른 방법을 강구해야 하는 듯 합니다. JNI callback 을 사용하지 말아야 한다면, JNI 메소드를 부르되 signal 이 올 때까지 blocking 이 걸려있으면 될 듯 한데, 어디 한번 또 해 볼까요.... [두번째 예제] "gracefully exiting" 기본적인 개념은 별도의 자바 Thread 가 C native 코드를 호출하여 특정 signal 이 발생할 때 까지 기다리게 됩니다. javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# ls -alF total 24 4 drwxr-xr-x 3 root root 4096 Jan 2 02:30 ./ 4 drwxrwxrwx 7 guest users 4096 Jan 2 01:43 ../ 4 -rw-r--r-- 1 root root 129 Jan 2 01:43 cc 4 drwxr-xr-x 3 root root 4096 Jan 2 01:43 org/ 4 -rw-r--r-- 1 root root 269 Jan 2 02:26 signalhandle2.c javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# ls -alF org/jsn/signal/ total 24 4 drwxr-xr-x 2 root root 4096 Jan 2 02:03 ./ 4 drwxr-xr-x 3 root root 4096 Jan 2 01:43 ../ 4 -rw-r--r-- 1 root root 488 Jan 2 02:03 SignalMonitor.java 4 -rw-r--r-- 1 root root 505 Jan 2 02:00 SignalTest2.java javaservice:/home/guest/source/signal2# cat org/jsn/signal/SignalMonitor.java package org.jsn.signal; public class SignalMonitor extends Thread { static { try{ System.loadLibrary("signalhandle2"); }catch(Exception e){ e.printStackTrace(); } } public SignalMonitor(){ super(); } public void run(){ signal_wait(15); // SIGTERM System.out.println("I've got SIGTERM signal"); System.out.println("program terminated gracefully"); System.exit(1); } public native synchronized void signal_wait(int signum); } javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# cat org/jsn/signal/SignalTest2.java package org.jsn.signal; public class SignalTest2 { public SignalTest2() { SignalMonitor monitor = new SignalMonitor(); monitor.start(); System.out.println("signal listening"); } public void do_something(){ // infinite loop for(int i=0; true ; i++) { System.out.println("waiting..." + i); try{Thread.sleep(1000 * 10);}catch(Exception e){} } } public static void main(String[] args){ SignalTest2 test = new SignalTest2(); test.do_something(); } } javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# javac org/jsn/signal/*.java javaservice:/home/guest/source/signal2# ls -alF org/jsn/signal/ total 24 4 drwxr-xr-x 2 root root 4096 Jan 2 02:44 ./ 4 drwxr-xr-x 3 root root 4096 Jan 2 01:43 ../ 4 -rw-r--r-- 1 root root 813 Jan 2 02:55 SignalMonitor.class 4 -rw-r--r-- 1 root root 489 Jan 2 02:44 SignalMonitor.java 4 -rw-r--r-- 1 root root 953 Jan 2 02:55 SignalTest2.class 4 -rw-r--r-- 1 root root 505 Jan 2 02:00 SignalTest2.java javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# javah -jni org.jsn.signal.SignalMonitor javaservice:/home/guest/source/signal2# ls -alF total 40 4 drwxr-xr-x 3 root root 4096 Jan 2 02:05 ./ 4 drwxrwxrwx 7 guest users 4096 Jan 2 01:43 ../ 4 -rw-r--r-- 1 root root 129 Jan 2 01:43 cc 4 drwxr-xr-x 3 root root 4096 Jan 2 01:43 org/ 4 -rw-r--r-- 1 root root 487 Jan 2 02:05 org_jsn_signal_SignalMonitor.h 4 -rw-r--r-- 1 root root 269 Jan 2 02:26 signalhandle2.c javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# cat org_jsn_signal_SignalMonitor.h /* DO NOT EDIT THIS FILE - it is machine generated */ #include <jni.h> /* Header for class org_jsn_signal_SignalMonitor */ #ifndef _Included_org_jsn_signal_SignalMonitor #define _Included_org_jsn_signal_SignalMonitor #ifdef __cplusplus extern "C" { #endif /* * Class: org_jsn_signal_SignalMonitor * Method: signal_wait * Signature: (I)V */ JNIEXPORT void JNICALL Java_org_jsn_signal_SignalMonitor_signal_1wait (JNIEnv *, jobject, jint); #ifdef __cplusplus } #endif #endif javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# cat signalhandle2.c #include <signal.h> #include "org_jsn_signal_SignalMonitor.h" int signal_reached = 0; void signal_handle(signum) int signum; { signal_reached = 1; } /* * Class: org_jsn_signal_SignalMonitor * Method: signal_wait * Signature: (I)V */ JNIEXPORT void JNICALL Java_org_jsn_signal_SignalMonitor_signal_1wait (JNIEnv *env, jobject obj, jint signum) { signal_reached = 0; signal(signum, signal_handle); while ( signal_reached == 0 ) ; /* CPU를 다소 점유할텐데, 더 좋은 방법 있나요? */ } javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# cat cc #!/bin/sh gcc -shared -I/usr/java/include \ -I/usr/java/include/linux \ -o libsignalhandle2.so signalhandle2.c javaservice:/home/guest/source/signal2# javaservice:/home/guest/source/signal2# sh cc javaservice:/home/guest/source/signal2# ls -alF total 32 4 drwxr-xr-x 3 root root 4096 Jan 2 02:36 ./ 4 drwxrwxrwx 7 guest users 4096 Jan 2 01:43 ../ 4 -rw-r--r-- 1 root root 112 Jan 2 02:35 cc 8 -rwxr-xr-x 1 root root 5299 Jan 2 02:36 libsignalhandle2.so* 4 drwxr-xr-x 3 root root 4096 Jan 2 01:43 org/ 4 -rw-r--r-- 1 root root 482 Jan 2 02:29 org_jsn_signal_SignalMonitor.h 4 -rw-r--r-- 1 root root 283 Jan 2 02:36 signalhandle2.c 이제 실행시켜 보겠습니다. javaservice:/home/guest/source/signal2# java org.jsn.signal.SignalTest2 signal listening waiting...0 waiting...1 ...... 실행되고 있는 중에 다른 Terminal 창에서 다음과 같이 SIGTERM(15) 을 날립니다. [Terminal B] javaservice:/root# ps -ef|grep java|grep root root 19104 15065 4 02:50 pts/4 00:00:00 /usr/java/bin/linux/native_threa root 19112 19104 0 02:50 pts/4 00:00:00 /usr/java/bin/linux/native_threa root 19113 19112 0 02:50 pts/4 00:00:00 /usr/java/bin/linux/native_threa root 19114 19112 0 02:50 pts/4 00:00:00 /usr/java/bin/linux/native_threa root 19115 19112 99 02:50 pts/4 00:00:05 /usr/java/bin/linux/native_threa root 19117 15768 0 02:50 pts/3 00:00:00 grep java javaservice:/root# kill -15 19104 javaservice:/root# 결과는 다음과 같습니다. javaservice:/home/guest/source/signal2# java org.jsn.signal.SignalTest2 signal listening waiting...0 waiting...1 I've got SIGTERM signal program terminated gracefully javaservice:/home/guest/source/signal2# 원하시는 답변이 되었기를 바랍니다. ---------------------------------------------------------------------------------- 2000.1.4 CPU 점거현상 보완 추가 CPU를 점거하는 문제를 해결하였습니다. 아래 문서를 참조하세요. "CPU 점거현상 보완 추가" http://www.javaservice.net/~java/bbs/read.cgi?m=devtip&b=javatip&c=r_p&n=978538886 [첨부A signal.h : Linux] /* Signals. */ #define SIGHUP 1 /* Hangup (POSIX). */ #define SIGINT 2 /* Interrupt (ANSI). */ #define SIGQUIT 3 /* Quit (POSIX). */ #define SIGILL 4 /* Illegal instruction (ANSI). */ #define SIGTRAP 5 /* Trace trap (POSIX). */ #define SIGABRT 6 /* Abort (ANSI). */ #define SIGIOT 6 /* IOT trap (4.2 BSD). */ #define SIGBUS 7 /* BUS error (4.2 BSD). */ #define SIGFPE 8 /* Floating-point exception (ANSI). */ #define SIGKILL 9 /* Kill, unblockable (POSIX). */ #define SIGUSR1 10 /* User-defined signal 1 (POSIX). */ #define SIGSEGV 11 /* Segmentation violation (ANSI). */ #define SIGUSR2 12 /* User-defined signal 2 (POSIX). */ #define SIGPIPE 13 /* Broken pipe (POSIX). */ #define SIGALRM 14 /* Alarm clock (POSIX). */ #define SIGTERM 15 /* Termination (ANSI). */ #define SIGSTKFLT 16 /* Stack fault. */ #define SIGCLD SIGCHLD /* Same as SIGCHLD (System V). */ #define SIGCHLD 17 /* Child status has changed (POSIX). */ #define SIGCONT 18 /* Continue (POSIX). */ #define SIGSTOP 19 /* Stop, unblockable (POSIX). */ #define SIGTSTP 20 /* Keyboard stop (POSIX). */ #define SIGTTIN 21 /* Background read from tty (POSIX). */ #define SIGTTOU 22 /* Background write to tty (POSIX). */ #define SIGURG 23 /* Urgent condition on socket (4.2 BSD). */ #define SIGXCPU 24 /* CPU limit exceeded (4.2 BSD). */ #define SIGXFSZ 25 /* File size limit exceeded (4.2 BSD). */ #define SIGVTALRM 26 /* Virtual alarm clock (4.2 BSD). */ #define SIGPROF 27 /* Profiling alarm clock (4.2 BSD). */ #define SIGWINCH 28 /* Window size change (4.3 BSD, Sun). */ #define SIGPOLL SIGIO /* Pollable event occurred (System V). */ #define SIGIO 29 /* I/O now possible (4.2 BSD). */ #define SIGPWR 30 /* Power failure restart (System V). */ #define SIGUNUSED 31 ------------------------------------------------------- 본 문서는 자유롭게 배포/복사 할 수 있으나 반드시 이 문서의 저자에 대한 언급을 삭제하시면 안됩니다 ================================================ 자바서비스넷 이원영 E-mail: javaservice@hanmail.net PCS:019-310-7324 ================================================

제목 : Re: CPU 점거 보완 글쓴이: 까막(guest) 2001/01/02 09:56:52 조회수:1756 줄수:10

안녕하세요 첨뵙겠습니다 ^^ Splenit의 까막이라고 합니다. while문에 의한 부하문제는 sleep()으로 재운다음에 raise(SIGARLM)으로 깨우면 될 듯 합니다. 즉 signal_reached = 1; 대신에 raise(SIGALRM) while(signal_reached == 0) 이 아니라 sleep(0) 가 되겠죠 ^^ 이러면 while문에의한 CPU점거문제는 해결될듯 합니다. Java는 아니고 C로 데몬짤때 썼던 코드입니당~~

제목 : CPU 점거현상 보완 추가 글쓴이: 이원영(javaservice) 2001/01/04 01:21:26 조회수:3744 줄수:119

2000.1.4 CPU 점거현상 보완 추가 까막님(whitecrw@orgio.net)이 raise(SIGALRM)과 sleep() 을 이용해 보라고 하셨는데, 막상 해 보니 sleep() 이 완전한 blocking 에 빠지지 않고 대략 8초 후에 그냥 빠져나와 버리더군요... 테스트한 소스는 다음과 같습니다. --------------------------------------- void signal_handle(signum) int signum; { raise(SIGALRM); } NIEXPORT void JNICALL Java_org_jsn_signal_SignalMonitor_signal_1wait (JNIEnv *env, jobject obj, jint signum) { signal(signum, signal_handle); sleep(0); } --------------------------------------- GNU의 signal 처리기법에 관련한 문서에 보면 그와 같은 문제가 있다고 지적되어 있으며, 다음과 같이 하라고 명시되어 있습니다. Sample 1: --------------------------------------- int signal_reached = 0; void signal_handle(signum) int signum; { signal_reached = 1; } JNIEXPORT void JNICALL Java_org_jsn_signal_SignalMonitor_signal_1wait (JNIEnv *env, jobject obj, jint signum) { signal_reached = 0; signal(signum, signal_handle); while( ! signal_reached ) sleep(1); } --------------------------------------- 이 예제는 제대로 잘 동작합니다. 그러나, 그 문서에는 이러한 프로그래밍 보다는 아래와 같은 방법을 사용하도록 권하고 있습니다. Sample 2: --------------------------------------- .... int signal_reached = 0; void signal_handle(signum) int signum; { signal_reached = 1; } JNIEXPORT void JNICALL Java_org_jsn_signal_SignalMonitor_signal_1wait (JNIEnv *env, jobject obj, jint signum) { sigset_t mask, oldmask; signal_reached = 0; signal(signum, signal_handle); sigemptyset (&mask); sigaddset (&mask, SIGUSR1); sigprocmask (SIG_BLOCK, &mask, &oldmask); while(!signal_reached) sigsuspend (&oldmask); sigprocmask (SIG_UNBLOCK, &mask, NULL); } --------------------------------------- 이 방법이 답일 듯 합니다. GNU 관련 문서는 아래에 있습니다. http://www.gnu.org/manual/glibc-2.0.6/html_chapter/libc_toc.html http://www.gnu.org/manual/glibc-2.0.6/html_chapter/libc_21.html#SEC381 NOTE: 이 경우, JDK THREADS_FLAG 가 native 로 되어 있을 경우는 kill 명령어를 날릴 때 잘 찾아서 날려야 합니다. native thread 모드에서는 여러개의 프로세스들이 나타납니다. 예를 들면, javaservice:/root# ps -ef|grep java|grep root root 24430 23282 0 00:50 pts/3 00:00:00 /usr/java/bin/linux/native_threa root 24438 24430 0 00:50 pts/3 00:00:00 /usr/java/bin/linux/native_threa root 24439 24438 0 00:50 pts/3 00:00:00 /usr/java/bin/linux/native_threa root 24440 24438 0 00:50 pts/3 00:00:00 /usr/java/bin/linux/native_threa root 24441 24438 0 00:50 pts/3 00:00:00 /usr/java/bin/linux/native_threa root 24467 23416 0 00:51 pts/4 00:00:00 grep java javaservice:/root# kill -15 24441 처럼, 제일 마지막 프로세스가 JNI 관련한 thread 처럼 보이며, 해당 프로세스 ID 에 signal 을 날려야 되더군요... 반면 THREADS_FLAG=green 일 경우는 아래 처럼 프로세스가 하나이니 별 혼선이 없네요. javaservice:/root# ps -ef|grep java|grep root root 24565 23282 5 00:53 pts/3 00:00:00 /usr/java/bin/i686/green_threads root 24582 23416 0 00:53 pts/4 00:00:00 grep java javaservice:/root# kill -15 24565 ------------------------------------------------------- 본 문서는 자유롭게 배포/복사 할 수 있으나 반드시 이 문서의 저자에 대한 언급을 삭제하시면 안됩니다 ================================================ 자바서비스넷 이원영 E-mail: javaservice@hanmail.net PCS:019-310-7324 ================================================