在Windows下使用GCJ+SWT的实例

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在Windows下使用GCJ+SWT的实例

GCJ可以把JAVA程序编译成本地代码，编译成功后的exe文件不再需要JRE就可直接运行，编译成本地后的程序运行速度有所提高。缺点是生成后的文件较大，我试了一个hello world都要两兆多，用WinRAR压缩后为600多K。

 

安装及配置

1.       下载MinGW。(http://sourceforge.net/projects/mingw )

网址：http://sourceforge.net/project/showfiles.php?group_id=2435

需要下载下列文件：

MinGW-2.0.0-3.exe (在Windows下的GNU环境)

MSYS-1.0.8.exe （一个模拟的*nix 支持shell等）

gcj-3.2-20021210-1.tar.gz （主角GCJ编译java为本地代码）

2.       安装文件

依次安装MinGW-2.0.0-3.exe、MSYS-1.0.8.exe

安装MSYS时会有提示要你输入MinGW的路径。

解压缩gcj-3.2-20021210-1.tar.gz将里面的文件复制到MinGW下，注意对应文件夹，比如gcj\bin下文件要放到对应的MinGW\bin下面。

 

3.       设置Windows的PATH把MinGW\bin加到系统的PATH里，方便以后运行gcj

 

然后在命令行里输入gcj –v 看看吧：）

HelloGCJ.exe

为了方便描述，让我们先建立一个gcjwork文件夹，

在gcjwork中建立一个普通的java源文件，HelloGCJ.java

public class HelloGCJ {

    public static void main(String[] args) {

        System.out.println("Hello GCJ!");

    }

}

同目录下新建一个文本文件Makefile注意不要带扩展名。

TARGET=HelloGCJ

GCJ=gcj

 

all: $(TARGET)

 

$(TARGET): $(TARGET).o

       $(GCJ) --main=$(TARGET) -o $(TARGET) $(TARGET).o

 

$(TARGET).o: $(TARGET).java

       $(GCJ) -c $(TARGET).java -o $(TARGET).o

 

.PHONY: clean

 

clean:

       rm -rf *.o $(TARGET)

 

然后让我们打开MSYS使用cd进入到我们建立的gcjwork下，输入make

之后即可生成一个HelloGCJ.exe，运行他，这可是一个没有用虚拟机的用java写的程序哦。：）

 

对比一下

为什么要把java便以成本地代码呢？

执行速度加快是一个很主要的特点，让我们做一个最最简单的对比。

还是上例的HelloGCJ，我们编译成java的bytecode

注意gcj也可以编译bytecode,

使用gcj –C HelloGCJ.java 命令即可。

然后对比运行两个程序，在我的机器上可以明显感觉到HelloGCJ.class在执行时顿了一下。

而HelloGCJ.exe则直接相应输出了文字。

 

 

再来搞搞SWT

      

用过Eclipse就知道SWT，SWT是IBM的图形界面开发包，因为它的实现也是与本地化有关，所以引来不少的争议，公说公有理婆说婆有理，我们就不说什么了，直接说怎么使用它，毕竟是好是坏，用了才知道！

 

       准备

       1．swt.jat (SWT的java包，编译java要用)

       2．SWT的windows版本对应的dll(我的的文件名是swt-win32-2133.dll)

       上面这两个文件可以在eclipse下载最新的SWT工具包

       http://download2.eclipse.org/downloads/drops/R-2.1-200303272130/swt-2.1-win32.zip

 

       3．用于编译exe的libswt.a文件（我生成了一个，在这里下载）

       http://www.elvala.com/download/java/libswt.rar

 

       开始

       我们使用的是eclipse的例子程序，源代码如下：

 

import org.eclipse.swt.*;

import org.eclipse.swt.widgets.*;

import org.eclipse.swt.layout.*;

import org.eclipse.swt.events.*;

import org.eclipse.swt.graphics.*;

 

public class ComplexGridLayoutExample {

   static Display display;

   static Shell shell;

   static Text dogName;

   static Combo dogBreed;

   static Canvas dogPhoto;

   static Image dogImage;

   static List categories;

   static Text ownerName;

   static Text ownerPhone;

 

   public static void main(String[] args) {

       display = new Display();

       shell = new Shell(display);

       shell.setText("Dog Show Entry");

       GridLayout gridLayout = new GridLayout();

       gridLayout.numColumns = 3;

       shell.setLayout(gridLayout);

    

       new Label(shell, SWT.NONE).setText("Dog's Name:");

       dogName = new Text(shell, SWT.SINGLE | SWT.BORDER);

       GridData gridData = new GridData(GridData.HORIZONTAL_ALIGN_FILL);

       gridData.horizontalSpan = 2;

       dogName.setLayoutData(gridData);

 

       new Label(shell, SWT.NONE).setText("Breed:");

       dogBreed = new Combo(shell, SWT.NONE);

       dogBreed.setItems(new String [] {"Collie", "Pitbull", "Poodle", "Scottie"});

       dogBreed.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL));

 

       Label label = new Label(shell, SWT.NONE);

       label.setText("Categories");

       label.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_CENTER));

     

       new Label(shell, SWT.NONE).setText("Photo:");

       dogPhoto = new Canvas(shell, SWT.BORDER);

       gridData = new GridData(GridData.FILL_BOTH);

       gridData.widthHint = 80;

       gridData.heightHint = 80;

       gridData.verticalSpan = 3;

       dogPhoto.setLayoutData(gridData);

       dogPhoto.addPaintListener(new PaintListener() {

          public void paintControl(final PaintEvent event) {

              if (dogImage != null) {

                 event.gc.drawImage(dogImage, 0, 0);

              }

          }

       });

 

       categories = new List(shell, SWT.MULTI | SWT.BORDER | SWT.V_SCROLL);

       categories.setItems(new String [] {

          "Best of Breed", "Prettiest Female", "Handsomest Male",

          "Best Dressed", "Fluffiest Ears", "Most Colors",

          "Best Performer", "Loudest Bark", "Best Behaved",

          "Prettiest Eyes", "Most Hair", "Longest Tail",

          "Cutest Trick"});

       gridData = new GridData(GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL);

       gridData.verticalSpan = 4;

       int listHeight = categories.getItemHeight() * 12;

       Rectangle trim = categories.computeTrim(0, 0, 0, listHeight);

       gridData.heightHint = trim.height;

       categories.setLayoutData(gridData);

     

       Button browse = new Button(shell, SWT.PUSH);

       browse.setText("Browse...");

       gridData = new GridData(GridData.HORIZONTAL_ALIGN_FILL);

       gridData.horizontalIndent = 5;

       browse.setLayoutData(gridData);

       browse.addSelectionListener(new SelectionAdapter() {

          public void widgetSelected(SelectionEvent event) {

              String fileName = new FileDialog(shell).open();

              if (fileName != null) {

                 dogImage = new Image(display, fileName);

              }

          }

       });

     

       Button delete = new Button(shell, SWT.PUSH);

       delete.setText("Delete");

       gridData = new GridData(GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_BEGINNING);

       gridData.horizontalIndent = 5;

       delete.setLayoutData(gridData);

       delete.addSelectionListener(new SelectionAdapter() {

          public void widgetSelected(SelectionEvent event) {

              if (dogImage != null) {

                 dogImage.dispose();

                 dogImage = null;

                 dogPhoto.redraw();

              }

          }

       });

     

       Group ownerInfo = new Group(shell, SWT.NONE);

       ownerInfo.setText("Owner Info");

       gridLayout = new GridLayout();

       gridLayout.numColumns = 2;

       ownerInfo.setLayout(gridLayout);

       gridData = new GridData(GridData.HORIZONTAL_ALIGN_FILL);

       gridData.horizontalSpan = 2;

       ownerInfo.setLayoutData(gridData);

     

       new Label(ownerInfo, SWT.NONE).setText("Name:");

       ownerName = new Text(ownerInfo, SWT.SINGLE | SWT.BORDER);

       ownerName.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

     

       new Label(ownerInfo, SWT.NONE).setText("Phone:");

       ownerPhone = new Text(ownerInfo, SWT.SINGLE | SWT.BORDER);

       ownerPhone.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

     

       Button enter = new Button(shell, SWT.PUSH);

       enter.setText("Enter");

       gridData = new GridData(GridData.HORIZONTAL_ALIGN_END);

       gridData.horizontalSpan = 3;

       enter.setLayoutData(gridData);

       enter.addSelectionListener(new SelectionAdapter() {

          public void widgetSelected(SelectionEvent event) {

              System.out.println("\nDog Name: " + dogName.getText());

              System.out.println("Dog Breed: " + dogBreed.getText());

              System.out.println("Owner Name: " + ownerName.getText());

              System.out.println("Owner Phone: " + ownerPhone.getText());

              System.out.println("Categories:");

              String cats[] = categories.getSelection();

              for (int i = 0; i < cats.length; i++) {

                 System.out.println("\t" + cats[i]);

              }

          }

       });

     

       shell.pack();

       shell.open();

       while (!shell.isDisposed()) {

          if (!display.readAndDispatch()) display.sleep();

       }

       if (dogImage != null) {

          dogImage.dispose();

       }

   }

}

      

 

       文件存为ComplexGridLayoutExample.java

       对应的Makefile 文件

 

TARGET=ComplexGridLayoutExample

GCJ=gcj

JFLAGS=--classpath=./swt.jar

LFLAGS=-L. -lswt

 

all: $(TARGET)

 

$(TARGET): $(TARGET).o

       $(GCJ) --main=$(TARGET) -o $(TARGET) $(TARGET).o $(LFLAGS)

 

$(TARGET).o: $(TARGET).java

       $(GCJ) $(JFLAGS) -c $(TARGET).java -o $(TARGET).o

.PHONY: clean

 

clean:

       rm -rf *.o $(TARGET)

 

       上面两个文件和swt.jar,libswt.a,swt-win32-2133.dll 放在一起，

       关于路径问题注意

       JFLAGS=--classpath=./swt.jar

LFLAGS=-L. –lswt

其中JFLAGS要对应swt.jar

LFLAGS要对应libswt.a

 

然后make!

运行生成的ComplexGridLayoutExample.exe

看到了吗？以后运行此程序只要和swt-win32-2133.dll在一起。

整个exe大概5兆多，似乎有些让人沮丧，太大啦，但是这东西的确很奇妙，

据说C# editor:SharpStudio将使用SWT来制作！SWT封装了很多功能，你会发现写应用程序会比使用Swing等要方便很多。

 

直接下载编译好的例子 ComplexGridLayoutExample.exe

http://www.elvala.com/download/java/gcj.rar