你看:C:\>java Usage: java [-options] class [args...] (to execute a class) or java -jar [-options] jarfile [args...] (to execute a jar file)where options include: -client to select the "client" VM -server to select the "server" VM -hotspot is a synonym for the "client" VM [deprecated] The default VM is client. -cp -classpath <directories and zip/jar files separated by ;> set search path for application classes and resources -D<name>=<value> set a system property -verbose[:class|gc|jni] enable verbose output -version print product version and exit -showversion print product version and continue -? -help print this help message -X print help on non-standard options -ea[:<packagename>...|:<classname>] -enableassertions[:<packagename>...|:<classname>] enable assertions -da[:<packagename>...|:<classname>] -disableassertions[:<packagename>...|:<classname>] disable assertions -esa | -enablesystemassertions enable system assertions -dsa | -disablesystemassertions disable system assertions
C:\java练习>java Temp
1000000000
4306C:\java练习>java -client Temp
1000000000
4407C:\java练习>java -server Temp
Error: no `server' JVM at `C:\Program Files\Java\j2re1.4.0\bin\server\jvm.dll'.
如果先运行Java -server呢?是不是跟cache命中有关呢?
Usage: java [-options] class [args...]
(to execute a class)
or java -jar [-options] jarfile [args...]
(to execute a jar file)where options include:
-client to select the "client" VM
-server to select the "server" VM
-hotspot is a synonym for the "client" VM [deprecated]
The default VM is client. -cp -classpath <directories and zip/jar files separated by ;>
set search path for application classes and resources
-D<name>=<value>
set a system property
-verbose[:class|gc|jni]
enable verbose output
-version print product version and exit
-showversion print product version and continue
-? -help print this help message
-X print help on non-standard options
-ea[:<packagename>...|:<classname>]
-enableassertions[:<packagename>...|:<classname>]
enable assertions
-da[:<packagename>...|:<classname>]
-disableassertions[:<packagename>...|:<classname>]
disable assertions
-esa | -enablesystemassertions
enable system assertions
-dsa | -disablesystemassertions
disable system assertions
能把这个的结果贴出来么?
1000000000
10C:\Program Files\Java2SDK\bin>java testapp.Temp
1000000000
11076
java version "1.4.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-b92)
Java HotSpot(TM) Client VM (build 1.4.0-b92, mixed mode)
java version "1.4.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-b92)
Java HotSpot(TM) Server VM (build 1.4.0-b92, mixed mode)
www.javagaming.org
不知道为什么。
java version "1.4.0_01"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0_01-b03)
Java HotSpot(TM) Client VM (build 1.4.0_01-b03, mixed mode)好象和版本有关系。
import javax.swing.*;public class ShowButton extends JFrame
{
JButton f1 = new JButton();
JButton f2 = new JButton();
JButton f3 = new JButton();
JButton f4 = new JButton();
JButton f5 = new JButton();
JButton f6 = new JButton();
JButton f7 = new JButton();
JButton f8 = new JButton();
JButton f9 = new JButton(); private JButton[] buttonArray={f1,f2,f3,f4,f5,f6,f7,f8,f9};
JPanel pane = new JPanel(); public static void main(String args[]){
long start = System.currentTimeMillis(); new ShowButton(); long time = System.currentTimeMillis() - start;
System.out.println(time);
} public ShowButton(){
try{
jbInit();
}catch(Exception e) {
e.printStackTrace();
}
} private void jbInit() throws Exception {
pane.setLayout(null);
for(int i=0;i<9;i++) {
buttonArray[i].setBounds(50,80*i+50,80,40);
buttonArray[i].setText("Button"+i);
pane.add(buttonArray[i]);
}
pane.setPreferredSize(new Dimension(200,750)); JScrollPane scrollPane=new JScrollPane(pane);// scrollPane.setPreferredSize(new Dimension(200,300));
this.getContentPane().add(scrollPane, BorderLayout.CENTER); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setBounds(50,50,300,200);
this.show();
}
}结果啊:
C:\Program Files\Java2SDK\bin>java ShowButton
1162C:\Program Files\Java2SDK\bin>java -server ShowButton
1332C:\Program Files\Java2SDK\bin>java ShowButton
1152C:\Program Files\Java2SDK\bin>java -server ShowButton
1312