public class ExamGCJ {
         public static void main(String[] args) {
                  System.out.println("ExamGCJ Class GCJ Test");
         }
}

# gcj --main=ExamGCJ ExamGCJ.java -o ExamGCJ

public class ExamGCJ {
         public static void main(String[] args) {
                  System.out.println("Two Class GCJ Test");
                  new LibExamGCJ();
         }
}

public class LibExamGCJ {
         LibExamGCJ() {
                  System.out.println("Two Class GCJ Test --- this is print in lib");
         }
}

# gcj -c LibExamGCJ.java
# gcj -c ExamGCJ.java
# gcj --main=ExamGCJ ExamGCJ.o LibExamGCJ.o -o ExamGCJ

# gcj -c LibExamGCJ.class

ForeachExam.java:16: error: Invalid declaration.
                for(File f : fileList){
                              ^

# ar -crs libexam.a LibExamGCJ.o

# gcj --main=ExamGCJ ExamGCJ.o -L.\ -lexam

# gcj -C LibExamGCJ.java
# jar cf swt.jar LibExamGCJ.class

./bin
./obj
./lib
./src

./src/org/nahome/hangulee/

package org.nahome.hangulee;
public class LibExamGCJ
{
  LibExamGCJ()
  {
    System.out.println("Two Class GCJ Test --- this is print in lib");
  }
}

package org.nahome.hangulee;
public class LibExamGCJ2
{
  LibExamGCJ2()
  {
    System.out.println("Two Class GCJ Test --- this is print in lib2");
  }
}

CLASSPATH = ./src;

OBJS = \
  obj/org_nahome_hangulee_LibExamGCJ.o \
  obj/org_nahome_hangulee_LibExamGCJ2.o

CLASSES = \
  bin/org/nahome/hangulee/LibExamGCJ.class \
  bin/org/nahome/hangulee/LibExamGCJ2.class

all:$(OBJS) $(CLASSES) exam.jar lib/libexam.a

lib/libexam.a:
        ar -crs ./lib/libexam.a ./obj/*.o

exam.jar:
        jar cf exam.jar -C bin .

bin/org/nahome/hangulee/LibExamGCJ.class:src/org/nahome/hangulee/LibExamGCJ.java
        gcj -C -fCLASSPATH=$(CLASSPATH) -d bin src/org/nahome/hangulee/LibExamGCJ.java

obj/org_nahome_hangulee_LibExamGCJ.o:src/org/nahome/hangulee/LibExamGCJ.java
        gcj --classpath=$(CLASSPATH) -c src/org/nahome/hangulee/LibExamGCJ.java \
        -o obj/org_nahome_hangulee_LibExamGCJ.o

bin/org/nahome/hangulee/LibExamGCJ2.class:src/org/nahome/hangulee/LibExamGCJ2.java
        gcj -C -fCLASSPATH=$(CLASSPATH) -d bin src/org/nahome/hangulee/LibExamGCJ2.java

obj/org_nahome_hangulee_LibExamGCJ2.o:src/org/nahome/hangulee/LibExamGCJ2.java
        gcj --classpath=$(CLASSPATH) -c src/org/nahome/hangulee/LibExamGCJ2.java \
        -o obj/org_nahome_hangulee_LibExamGCJ2.o

import org.nahome.hangulee.*;
public class ExamGCJ
{
  public static void main(String[] args)
  {
    System.out.println("Two Class GCJ Test");
    new LibExamGCJ();
    new LibExamGCJ2();
  }
}

gcj --classpath=(위 예제가 있는 디렉토리 경로)/exam.jar -c ExamGCJ.java -o ExamGCJ.o
gcj --main=ExamGCJ ExamGCJ.o -L(위 예제가 있는 디렉토리 경로) -lexam -o ExamGCJ

Two Class GCJ Test
Two Class GCJ Test --- this is print in lib
Two Class GCJ Test --- this is print in lib2

(위 예제가 있는 디렉토리 경로)/src

public class ExamClassforName
{
  public static void main(String[] args)
  {
    System.out.println("Class.forName Example");
    try
    {
      Class ex = Class.forName("TextClass");
    }
    catch(Exception e)
    {
      System.out.println("error = "+e.toString());
    }
  }
}

public interface forNameExamInterface
{
  void test();
}

public class forNameExam implements forNameExamInterface
{
  forNameExam()
  {
    System.out.println("forNameExample - initial");
  }
  public void test()
  {
    System.out.println("forNameExample - test");
  }
}

public class ExamClassforName
{
  public static void main(String[] args)
  {
    System.out.println("Class.forName Example");
    try
    {
      Class ex = Class.forName("forNameExam");
      forNameExamInterface obj = (forNameExamInterface)ex.newInstance();
      obj.test();
    }
    catch(Exception e)
    {
      System.out.println("error = "+e.toString());
    }
  }
}

OBJS = forNameExamInterface.o \
  ExamClassforName.o
CLASSES = forNameExam.class
MAINCLASS = ExamClassforName

all: $(CLASSES) $(OBJS)
  gcj --main=$(MAINCLASS) $(OBJS) -o $(MAINCLASS)

forNameExamInterface.o : forNameExamInterface.java
  gcj -c forNameExamInterface.java -o forNameExamInterface.o

ExamClassforName.o : ExamClassforName.java
  gcj -c ExamClassforName.java -o ExamClassforName.o

forNameExam.class : forNameExam.java
  gcj -C forNameExam.java

org.eclipse.swt.custom.TableCursor

void traverse... →boolean traverse...

org.eclipse.swt.custom.StyledText

javac -classpath .\src src/org/eclipse/swt/custom/StyledText.java

import org.eclipse.swt.widgets.*;
public class ExamSWT
{
  public static void main(String[] args)
  {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.open ();
    while (!shell.isDisposed ())
    {
      if (!display.readAndDispatch ()) display.sleep ();
    }
    display.dispose ();
  }
}

gcj -fjni -o sample sample.java

gcjh -jni sample

gcc -c sampNat.c
gcc -shared -o sampNat.dll sampNat.o

public class sample
{
  public native void myNative(String s);

  public void myJava(String s)
  {
    s = s + ", Java";
    System.out.println(s);
  }

  public static void main(String args[])
  {
    sample x = new sample();
    x.myJava("Hello");
    x.myNative("Hello, Java (from C)");
    x.myJava("Goodbye");
  }

  static
  {
    System.loadLibrary("sampNat");
  }
}

#include <jni.h>
#include "sample.h"
#include <stdio.h>

JNIEXPORT void JNICALL Java_sample_myNative (JNIEnv *env, jobject this, jstring s)
{
  jclass cls;
  jfieldID fid;
  jobject obj;
  jmethodID mid;

  printf("From C\n");

  cls = (*env)->FindClass(env, "java/lang/System");
  if (cls == 0) {
    printf("java/lang/System lookup failed\n");
    return;
  }
  fid = (*env)->GetStaticFieldID(env, cls, "out", "Ljava/io/PrintStream;");
  if (fid == 0) {
    printf("java/lang/System::out lookup failed\n");
    return;
  }
  obj = (*env)->GetStaticObjectField(env, cls, fid);
  if (obj == 0) {
    printf("GetStaticObjectField call failed\n");
    return;
  }
  cls = (*env)->GetObjectClass(env, obj);
  if (cls == 0) {
    printf("GetObjectClass(out) failed\n");
    return;
  }
  mid = (*env)->GetMethodID(env, cls, "println", "(Ljava/lang/String;)V");
  if (mid == 0) {
    printf("println method lookup failed\n");
    return;
  }
  (*env)->CallVoidMethod(env, obj, mid, s);
}

gcj -C sample.java
gcjh -jni sample
gcc -c sampNat.c -o sampNat.o
gcc -shared -o sampNat.dll sampNat.o
gcj -fjni -o sample sample.class --main=sample

# gcj -Os -s -march=pentium2 --main=Hello Hello.o

# strip Foo.exe

# gcj -s --main=bar.Foo *.o Foo

# gcj -s Bar.java //-s 효과없음
# gcj -s --main=Foo *.o Foo
# strip Bar.o
# gcj -s --main=Foo *.o Foo //Bar.o 안의 패키지를 찾을 수 없다는 에러

# upx -1 -o CompressedFoo.exe FatFoo.exe