Sun Java2 SDK 的例子中有 *.jar文件，是什么类型的文件？双击还可以执行它

Question

在win2000下显示的类型是: Executable Jar File
双击它还能直接执行,倒有点象.exe

Answer 1

把你做的所有的java内容包括在一起，方便你的执行跟使用
但你的机器上依然要先安装JDK，并且设置好环境（windows下）

Answer 2

因为你在安装jdk的时候会自动关联程序类型，使用javaw来打开*.jar文件

Answer 3

其实是一种压缩文件,可以用WinRAR打开看到里面的组织结构和解压

Answer 4

奇怪的是在命令行状态下执行:
   jdk\bin\jawaw.exe  javasound.jar
显示错误:  not found main class

Answer 5

在windows中，除了应用程序，每种类型的文件都有它的打开方式，双击.jar文件其实是用javaw打开。
.jar文件是java类文件的打包文件，可以用winzip等解压软件察看其内容。并不是所有的.jar都可以运行，可以运行的.jar文件中应有一个主类，主类中有main()入口；/lib目录下的.jar是不能通过双击它来运行的，里面放了一些我们要引用的类，类似于c中的.h文件。

Answer 6

果然不错,用winzip打开Javasound.jar 驱动器 C 中的卷没有标签。
 卷的序列号是 98B2-E975 C:\jdk\demo\sound0 的目录2001-12-20  09:48       <DIR>          .
2001-12-20  09:48       <DIR>          ..
2001-12-20  09:48                    0 bad.txt
2001-08-08  13:46                    0 CapturePlayback$1.class
2001-08-08  13:46                    0 CapturePlayback$2.class
2001-08-08  13:46                    0 CapturePlayback$Capture.class
2001-08-08  13:46                    0 CapturePlayback$FormatControls.class
2001-08-08  13:46                    0 CapturePlayback$Playback.class
2001-08-08  13:46                    0 CapturePlayback$SamplingGraph.class
2001-08-08  13:46                    0 CapturePlayback.class
2001-08-08  13:46                    0 ControlContext.class
2001-08-08  13:46                    0 Groove$1.class
2001-08-08  13:46                    0 Groove$2.class
2001-08-08  13:46                    0 Groove$3.class
2001-08-08  13:46                    0 Groove$4.class
2001-08-08  13:46                    0 Groove$5.class
2001-08-08  13:46                    0 Groove$Data.class
2001-08-08  13:46                    0 Groove.class
2001-08-08  13:46                    0 JavaSound$1.class
2001-08-08  13:46                    0 JavaSound$2.class
2001-08-08  13:46                    0 JavaSound$3.class
2001-08-08  13:46                    0 JavaSound$4.class
2001-08-08  13:46                    0 JavaSound.class
2001-08-08  13:46                    0 JavaSoundApplet.class
2001-08-08  13:46                    0 Juke$1.class
2001-08-08  13:46                    0 Juke$2.class
2001-08-08  13:46                    0 Juke$Credits.class
2001-08-08  13:46                    0 Juke$JukeControls.class
2001-08-08  13:46                    0 Juke$JukeTable.class
2001-08-08  13:46                    0 Juke$Loading.class
2001-08-08  13:46                    0 Juke$PlaybackMonitor.class
2001-08-08  13:46                    0 Juke.class
2001-12-20  09:47       <DIR>          media
2001-12-20  09:47       <DIR>          META-INF
2001-08-08  13:46                    0 MidiSynth$1.class
2001-08-08  13:46                    0 MidiSynth$2.class
2001-08-08  13:46                    0 MidiSynth$3.class
2001-08-08  13:46                    0 MidiSynth$4.class
2001-08-08  13:46                    0 MidiSynth$5.class
2001-08-08  13:46                    0 MidiSynth$6.class
2001-08-08  13:46                    0 MidiSynth$7.class
2001-08-08  13:46                    0 MidiSynth$8.class
2001-08-08  13:46                    0 MidiSynth$ChannelData.class
2001-08-08  13:46                    0 MidiSynth$Controls.class
2001-08-08  13:46                    0 MidiSynth$InstrumentsTable.class
2001-08-08  13:46                    0 MidiSynth$Key.class
2001-08-08  13:46                    0 MidiSynth$Piano.class
2001-08-08  13:46                    0 MidiSynth$RecordFrame$TrackData.class
2001-08-08  13:46                    0 MidiSynth$RecordFrame.class
2001-08-08  13:46                    0 MidiSynth.class
2001-08-08  13:46                    0 Runner$1.class
2001-08-08  13:46                    0 Runner$2.class
2001-08-08  13:46                    0 Runner$3.class
2001-08-08  13:46                    0 Runner$4.class
2001-08-08  13:46                    0 Runner$CapturePlaybackModule.class
2001-08-08  13:46                    0 Runner$DataProperties.class
2001-08-08  13:46                    0 Runner$GrooveModule.class
2001-08-08  13:46                    0 Runner$JukeModule.class
2001-08-08  13:46                    0 Runner$MethodData.class
2001-08-08  13:46                    0 Runner$MidiSynthModule.class
2001-08-08  13:46                    0 Runner$ModuleData.class
2001-08-08  13:46                    0 Runner$SelectionUI$TreeRenderer.class
2001-08-08  13:46                    0 Runner$SelectionUI.class
2001-08-08  13:46                    0 Runner.class
2001-08-08  13:46                    0 TempoDial$1.class
2001-08-08  13:46                    0 TempoDial$2.class
2001-08-08  13:46                    0 TempoDial$3.class
2001-08-08  13:46                    0 TempoDial$Data.class
2001-08-08  13:46                    0 TempoDial.class
              65 个文件              0 字节
               4 个目录  2,839,803,904 可用字节

Answer 7

但都是0 字节,winzip不能正确识别它,
WinRAR才行

Answer 8

怎样才能将java程序打包成.Jar呢?

Answer 9

jdk中提供了jar工具，具体使用方法可以查jdk文档，也可以直接用压缩软件进行打包，起名字的时候起成.jar就可以了，另外如果要通过命令行来运行.jar文件的话，格式应该是
java -jar filename.jar [ argument ... ] 
javaw -jar filename.jar [ argument ... ]
argument是可选项，是入口参数

Answer 10

*.jar文件是一个包文件,你可以将它的绝对路径添加到系统环境变量CLASSPATH里. 例如有个sb.jar文件. 查看其内容: jar tf sb.jar 解包: jar xf sb.jar 有a.class,b.class文件,打包成sb.jar jar cf sb.jar a.class b.class 可以使用通配符. jar cf sb.jar *.class 
jar cf sb.jar *.*你也可以在编译时JAVA程序时使用[-classpath PATHNAME]来指定目标[JAR]文件的路径。
使用时你可以放到classpath里就可以了！

Answer 11

人气很足,非常满意!!!!!!!!!!
刚开始学Java!
发分!!!!!!!!