Nadeem Awad

I suggest that you take a look at the Swing Timer. It's really easy to use and has many features.

Any help guys?

Hi all,
We have an application deployed on JBoss 4.0.4. Some parts of the application depend on accessing some web services. We are using Apache Axis 1.4 for that.
We had a need to deploy another version of a running application on the same server. After doing so, I noticed that the EJB classes are loaded in a shared class loader, which caused the web application to call the wrong EJBs. Consequently, we�ve changed the JBoss configuration to isolate EAR deployments as follows:
ear-deployer.xml: <attribute name=�Isolated�>true</attribute>
Then the two applications were successfully deployed on the same server. However, since then we�ve started receiving some unexpected exceptions from the server, when the application is trying to access any of the web services using the Axis client. The problem is that the exception message is not descriptive at all, and there�s no specific scenario to trigger them. When we first start up the JBoss, everything works fine. After a certain period of time, this exception happens and we have to restart the JBoss again to resolve it.
The exception stack trace is as follows:

Caused by: javax.ejb.EJBException: Unexpected Error java.lang.NoClassDefFoundError at org.apache.axis.configuration.FileProvider.configureEngine(FileProvider.java:179) at org.apache.axis.AxisEngine.init(AxisEngine.java:172) at org.apache.axis.AxisEngine.(AxisEngine.java:156) at org.apache.axis.client.AxisClient.(AxisClient.java:52) at org.apache.axis.client.Service.getAxisClient(Service.java:104) at org.apache.axis.client.Service.(Service.java:113) at com.elm.ais.services.erissuance.client.ExitEntryVisaLocator.(ExitEntryVisaLocator.java:14) at com.elm.ais.services.erissuance.ExitEntryVisaClient.getServiceProxy(ExitEntryVisaClient.java:229) at com.elm.ais.services.erissuance.ExitEntryVisaClient.validateAlienInformation(ExitEntryVisaClient.java:69) at com.elm.ais.ejb.blbeans.FunctionsBean.validateAlienInformation(FunctionsBean.java:2951) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.invocation.Invocation.performCall(Invocation.java:359) at org.jboss.ejb.StatelessSessionContainer$ContainerInterceptor.invoke(StatelessSessionContainer.java:237) at org.jboss.resource.connectionmanager.CachedConnectionInterceptor.invoke(CachedConnectionInterceptor.java:158) at org.jboss.ejb.plugins.StatelessSessionInstanceInterceptor.invoke(StatelessSessionInstanceInterceptor.java:169) at org.jboss.ws.server.ServiceEndpointInterceptor.invoke(ServiceEndpointInterceptor.java:64) at org.jboss.ejb.plugins.CallValidationInterceptor.invoke(CallValidationInterceptor.java:63) at org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInterceptor.java:121) at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInterceptorCMT.java:350) at org.jboss.ejb.plugins.TxInterceptorCMT.invoke(TxInterceptorCMT.java:181) at org.jboss.ejb.plugins.SecurityInterceptor.invoke(SecurityInterceptor.java:168) at org.jboss.ejb.plugins.LogInterceptor.invoke(LogInterceptor.java:205) at org.jboss.ejb.plugins.CleanShutdownInterceptor.invoke(CleanShutdownInterceptor.java:278) at org.jboss.ejb.plugins.ProxyFactoryFinderInterceptor.invoke(ProxyFactoryFinderInterceptor.java:136) at org.jboss.ejb.SessionContainer.internalInvoke(SessionContainer.java:648) at org.jboss.ejb.Container.invoke(Container.java:954) at org.jboss.ejb.plugins.local.BaseLocalProxyFactory.invoke(BaseLocalProxyFactory.java:430) at org.jboss.ejb.plugins.local.StatelessSessionProxy.invoke(StatelessSessionProxy.java:103) at $Proxy93.validateAlienInformation(Unknown Source) at com.elm.ais.ejb.AISFacadeBean.validateAlienInformation(AISFacadeBean.java:2688) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.invocation.Invocation.performCall(Invocation.java:359) at org.jboss.ejb.StatelessSessionContainer$ContainerInterceptor.invoke(StatelessSessionContainer.java:237) at org.jboss.resource.connectionmanager.CachedConnectionInterceptor.invoke(CachedConnectionInterceptor.java:158) at org.jboss.ejb.plugins.StatelessSessionInstanceInterceptor.invoke(StatelessSessionInstanceInterceptor.java:169) at org.jboss.ws.server.ServiceEndpointInterceptor.invoke(ServiceEndpointInterceptor.java:64) at org.jboss.ejb.plugins.CallValidationInterceptor.invoke(CallValidationInterceptor.java:63) at org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInterceptor.java:121) at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInterceptorCMT.java:404) at org.jboss.ejb.plugins.TxInterceptorCMT.invoke(TxInterceptorCMT.java:181) at org.jboss.ejb.plugins.SecurityInterceptor.invoke(SecurityInterceptor.java:168) at org.jboss.ejb.plugins.LogInterceptor.invoke(LogInterceptor.java:205) at org.jboss.ejb.plugins.CleanShutdownInterceptor.invoke(CleanShutdownInterceptor.java:278) at org.jboss.ejb.plugins.ProxyFactoryFinderInterceptor.invoke(ProxyFactoryFinderInterceptor.java:136) at org.jboss.ejb.SessionContainer.internalInvoke(SessionContainer.java:648) at org.jboss.ejb.Container.invoke(Container.java:954) at sun.reflect.GeneratedMethodAccessor209.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155) at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94) at org.jboss.mx.server.Invocation.invoke(Invocation.java:86) at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264) at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659) at org.jboss.invocation.local.LocalInvoker$MBeanServerAction.invoke(LocalInvoker.java:169) at org.jboss.invocation.local.LocalInvoker.invoke(LocalInvoker.java:118) at org.jboss.invocation.InvokerInterceptor.invokeLocal(InvokerInterceptor.java:206) at org.jboss.invocation.InvokerInterceptor.invoke(InvokerInterceptor.java:192) at org.jboss.proxy.ejb.RetryInterceptor.invoke(RetryInterceptor.java:176) at org.jboss.proxy.TransactionInterceptor.invoke(TransactionInterceptor.java:61) at org.jboss.proxy.SecurityInterceptor.invoke(SecurityInterceptor.java:70) at org.jboss.proxy.ejb.StatelessSessionInterceptor.invoke(StatelessSessionInterceptor.java:112) at org.jboss.proxy.ClientContainer.invoke(ClientContainer.java:100) at $Proxy92.validateAlienInformation(Unknown Source) at com.elm.ais.web.actions.ValidateAlienInfoForExitEntryVisaAction.performTask(ValidateAlienInfoForExitEntryVisaAction.java:69) at com.elm.ais.web.actions.ActionSuper.execute(ActionSuper.java:76) at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484) at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274) at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482) at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at javax.servlet.http.HttpServlet.service(HttpServlet.java:810) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.displaytag.filter.AISResponseOverrideFilter.doFilter(AISResponseOverrideFilter.java:58) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at com.elm.ais.web.filters.ChracterEncodingFilter.doFilter(ChracterEncodingFilter.java:37) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869) at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664) at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527) at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112) at java.lang.Thread.run(Thread.java:595) at org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInterceptor.java:237) at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInterceptorCMT.java:350) at org.jboss.ejb.plugins.TxInterceptorCMT.invoke(TxInterceptorCMT.java:181) at org.jboss.ejb.plugins.SecurityInterceptor.invoke(SecurityInterceptor.java:168) at org.jboss.ejb.plugins.LogInterceptor.invoke(LogInterceptor.java:205) at org.jboss.ejb.plugins.CleanShutdownInterceptor.invoke(CleanShutdownInterceptor.java:278) at org.jboss.ejb.plugins.ProxyFactoryFinderInterceptor.invoke(ProxyFactoryFinderInterceptor.java:136) at org.jboss.ejb.SessionContainer.internalInvoke(SessionContainer.java:648) at org.jboss.ejb.Container.invoke(Container.java:954) at org.jboss.ejb.plugins.local.BaseLocalProxyFactory.invoke(BaseLocalProxyFactory.java:430) at org.jboss.ejb.plugins.local.StatelessSessionProxy.invoke(StatelessSessionProxy.java:103) at $Proxy93.validateAlienInformation(Unknown Source) at com.elm.ais.ejb.AISFacadeBean.validateAlienInformation(AISFacadeBean.java:2688) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.invocation.Invocation.performCall(Invocation.java:359) at org.jboss.ejb.StatelessSessionContainer$ContainerInterceptor.invoke(StatelessSessionContainer.java:237) at org.jboss.resource.connectionmanager.CachedConnectionInterceptor.invoke(CachedConnectionInterceptor.java:158) at org.jboss.ejb.plugins.StatelessSessionInstanceInterceptor.invoke(StatelessSessionInstanceInterceptor.java:169) at org.jboss.ws.server.ServiceEndpointInterceptor.invoke(ServiceEndpointInterceptor.java:64) at org.jboss.ejb.plugins.CallValidationInterceptor.invoke(CallValidationInterceptor.java:63) at org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInterceptor.java:121) at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInterceptorCMT.java:404) at org.jboss.ejb.plugins.TxInterceptorCMT.invoke(TxInterceptorCMT.java:181) at org.jboss.ejb.plugins.SecurityInterceptor.invoke(SecurityInterceptor.java:168) at org.jboss.ejb.plugins.LogInterceptor.invoke(LogInterceptor.java:205) ... 54 more

Any help about this urgent issue will be highly appreciated

Originally posted by Henry Wong:


What are these one byte files? And even if they were one megabyte files, why would you need this? What does it matter if you have a one megabyte of unused disk space in a 4.6 gigabyte disk?

Henry

I didn't understand what one byte files are you talking about.

Anyway, I found what I've been looking for. It's a well-known problem called Bin Packing Problem. I've found many solution for it in the Source Forge as well.

Thanks a lot.

Originally posted by Henry Wong:
How about just a brute force recursive algorithm? You can try out every possible combination (done recursively), and then save the ones that uses the least amount of CDs.

Henry

Don't you think that this might take a huge amount of time? Especially in a scenario that we have - let's say - a 13 GB of data that I want to distribute over three (4.6 GB) DVD's.

Hi,
My problem is as follows:
I have a bunch of files that I would like to copy to a CD. The total size of these files let's say needs four to five CD's, depending on the way that you arrange the files. I need an algorithm that takes the sized of these files, and distribute them on the Maximum capacity of each CD, in a way to utilize the space of each CD.

Example:
Let's say a CD can contain 20 MB.
items:
(A) 10
(B) 5
(C) 4
(D) 3
(E) 2

if you sort the files based on their size - like above - most likely you'll choose the files as follows:
(A) 10, (B) 5, (C) 4, the total will be 19 MB and there will be 1 MB unused.

However, if you replace (C) with (D) and (E), you'll fill the remaining unused space efficiently.

Of course, this example is very easy to solve manually with a glance. But in case of more complicated scenarios with many files with different sizes, that task will be much harder.

So, any help?

I found out that it's an old bug in Axis, and it seems that there's no workaround for it.

http://issues.apache.org/jira/browse/AXIS-2295

It seems that I need to upgrade to Axis2, or find another WS provider.

Regards,

Anyone?

Hi all,
I have three web services to be accessed from my machine. The first two are located on a node that is connected to same LAN that my machine is connected on. And the third one is reachable over the internet and is used to send SMS messages.
In order to reach the third message, I have to set the http proxy settings for the web service client using the following code:
System.setProperty("http.proxySet", "true"); System.setProperty("http.proxyHost", myProxyIP); System.setProperty("http.proxyPort", myProxyPort);

Whereas the first two services doesn't need this proxy setting because they're already reachable on the network.

My problem is as follows:
If I call one of the first two services (with no proxy setting) and then call the third one (with proxy setting), then everything works fine, and any subsequent calls to any of the three services works perfectly.

On the other hand, if I call the third service first (the one with the proxy setting), and then call one of the other two, the Axis client tries to call these services with the same proxy setting, even if I remove the proxy setting from the System properties and AxisProperties:
System.setProperty("http.proxySet", "false"); System.getProperties().remove("http.proxyHost"); System.getProperties().remove("http.proxyPort"); AxisProperties.setProperty("http.proxyHost", null); AxisProperties.setProperty("http.proxyPort", null);

The problem in this case is that if the proxy server is unavailable for any reason, I can't access the other two services because the proxy setting is stuck somehow in the Axis Engine instance. So eventually I'm getting this exception:
AxisFault faultCode: {http://schemas.xmlsoap.org/soap/envelope/}Server.userException faultSubcode: faultString: java.net.UnkownHostException: <MyProxyServer>

Is there a way to resolve this?

Originally posted by Kelly Dolan:

myapp.ear - myapp.war [B]- aclientlib.jar - this jar contains classes required by clients using the ejb[/B] - Home.class - aejb.jar - this jar is the ejb! - Home.class - aclientlib.jar - this jar contains classes required by clients using the ejb - Home.class

That exception occurs when the WAR file includes any EJB-related classes, either in WEB-INF/lib or WEB-INF/classes folder. Remove any EJB-related JARs/Classes from the WAR and it should work fine.

For more info, check this link:

http://www.jboss.com/?module=bb&op=viewtopic&p=3896901

Originally posted by Ulf Dittmer:
Why do you consider it troubling to have a log field in all classes where you want to do logging?

I really find it better to create a wrapper class for the Logger and declare some static methods to be accessed directly from the methods, rather than creating a Logger object in each class. I believe the old fashin is a bit messy, that's why I decided to create the wrapper.

Anyway, for more info check out this thread:
http://forum.java.sun.com/thread.jspa?messageID=9484262

Any ideas? Anyone?

Hi,
I've been using Log4j, and I found it a little troublesome to declare an instance variable everywhere and pass the class name to it; like this:

public class UsesLogger { Logger logger = Logger.getLogger(this.class); ... public void log() { logger.debug("bla bla"); } }

So I thought I could create a wrapper class to encapsulate the logger. For instance:

public class MyLogger { public static void log(Class clazz, String message) { Logger logger = Logger.getLogger(clazz); logger.debug(message); } }

But I also didn't like passing the class object every time I want to log a message. So the following came to my mind:

public class MyLogger { private static Exception ex = new Exception(); public static void log(String message) { ex.fillInStackTrace(); StackTraceElement[] ste = ex.getStackTrace(); Logger logger = Logger.getLogger(ste[1].getClassName()); //I even can add the method name to the message using ste[1].getMethodName() logger.debug(message); } }

So the other classes do the following:

public class UsesLogger() { public void aMethod() { MyLogger.log("inside aMethod"); } }

My question is, is this approach efficient? especially that the ex.fillInStackTrace() method is synchronized, so it might be a bit costly.

Any ideas?
[ February 04, 2007: Message edited by: Nadeem Awad ]

I finally got it
I found some code on the java forums and I modified it to do what wanted.

package org.nadeem.gui; import java.awt.Component; import java.awt.Graphics; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.ItemListener; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.io.Serializable; import javax.swing.AbstractAction; import javax.swing.ActionMap; import javax.swing.ButtonGroup; import javax.swing.ButtonModel; import javax.swing.Icon; import javax.swing.JCheckBox; import javax.swing.SwingUtilities; import javax.swing.event.ChangeListener; import javax.swing.plaf.ActionMapUIResource; import javax.swing.plaf.UIResource; import javax.swing.plaf.metal.MetalLookAndFeel; public class TristateCheckBox extends JCheckBox { public static class State { private String desc = ""; private State() { } private State(String desc) { this.desc = desc; } public String toString() { return desc; } } public static final State NOT_SELECTED = new State("NOT_SELECTED"); public static final State CHECKED = new State("CHECKED"); public static final State CROSSED = new State("CROSSED"); private final TristateModel model; public TristateCheckBox(String text, State initial) { super(text); Icon icon = new TristateCheckBoxIcon(); super.setIcon(icon); // Add a listener for when the mouse is pressed and released super.addMouseListener(new MouseAdapter() { public void mousePressed(MouseEvent e) { TristateCheckBox.this.mousePressed(); } public void mouseReleased(MouseEvent e) { TristateCheckBox.this.mouseReleased(); } }); // Reset the keyboard action map ActionMap map = new ActionMapUIResource(); map.put("pressed", new AbstractAction() { public void actionPerformed(ActionEvent e) { TristateCheckBox.this.mousePressed(); } }); map.put("released", new AbstractAction() { public void actionPerformed(ActionEvent e) { TristateCheckBox.this.mouseReleased(); } }); SwingUtilities.replaceUIActionMap(this, map); // set the model to the adapted model model = new TristateModel(getModel()); setModel(model); setState(initial); } private void mousePressed() { grabFocus(); model.setPressed(true); model.setArmed(true); } private void mouseReleased() { model.nextState(); model.setArmed(false); model.setPressed(false); } public void doClick() { mousePressed(); mouseReleased(); } public TristateCheckBox(String text) { this(text, NOT_SELECTED); } public TristateCheckBox() { this(null); } /** No one may add mouse listeners, not even Swing! */ public void addMouseListener(MouseListener l) { } /** No one may set a new icon */ public void setIcon(Icon icon) { } /** * Set the new state to either CHECKED, CROSSED or NOT_SELECTED. */ public void setState(State state) { model.setState(state); } /** * Return the current state, which is determined by the selection status of * the model. */ public State getState() { return model.getState(); } public void setSelected(boolean selected) { if (selected) { setState(CHECKED); } else { setState(NOT_SELECTED); } } private class TristateModel implements ButtonModel { private final ButtonModel other; private State currentState = NOT_SELECTED; private TristateModel(ButtonModel other) { this.other = other; } private State getState() { return currentState; } private void setState(State state) { this.currentState = state; } public boolean isSelected() { return (currentState == CHECKED || currentState == CROSSED); } /** We rotate between NOT_SELECTED, CHECKED and CROSSED. */ private void nextState() { State current = getState(); if (current == NOT_SELECTED) { setState(CHECKED); } else if (current == CHECKED) { setState(CROSSED); } else if (current == CROSSED) { setState(NOT_SELECTED); } //This is to enforce a call to the fireStateChanged method other.setSelected(!other.isSelected()); } public void setArmed(boolean b) { other.setArmed(b); } /** * We disable focusing on the component when it is not enabled. */ public void setEnabled(boolean b) { try { setFocusable(b); } catch (Exception ex) { ex.printStackTrace(); }//catch other.setEnabled(b); } /** * All these methods simply delegate to the "other" model that is being * decorated. */ public boolean isArmed() { return other.isArmed(); } /* public boolean isSelected() { return other.isSelected(); } */ public boolean isEnabled() { return other.isEnabled(); } public boolean isPressed() { return other.isPressed(); } public boolean isRollover() { return other.isRollover(); } public void setSelected(boolean b) { other.setSelected(b); } public void setPressed(boolean b) { other.setPressed(b); } public void setRollover(boolean b) { other.setRollover(b); } public void setMnemonic(int key) { other.setMnemonic(key); } public int getMnemonic() { return other.getMnemonic(); } public void setActionCommand(String s) { other.setActionCommand(s); } public String getActionCommand() { return other.getActionCommand(); } public void setGroup(ButtonGroup group) { other.setGroup(group); } public void addActionListener(ActionListener l) { other.addActionListener(l); } public void removeActionListener(ActionListener l) { other.removeActionListener(l); } public void addItemListener(ItemListener l) { other.addItemListener(l); } public void removeItemListener(ItemListener l) { other.removeItemListener(l); } public void addChangeListener(ChangeListener l) { other.addChangeListener(l); } public void removeChangeListener(ChangeListener l) { other.removeChangeListener(l); } public Object[] getSelectedObjects() { return other.getSelectedObjects(); } } private class TristateCheckBoxIcon implements Icon, UIResource, Serializable { protected int getControlSize() { return 13; } public void paintIcon(Component c, Graphics g, int x, int y) { JCheckBox cb = (JCheckBox) c; TristateModel model = (TristateModel) cb.getModel(); int controlSize = getControlSize(); boolean drawCheck = model.getState() == CHECKED; boolean drawCross = model.getState() == CROSSED; if (model.isEnabled()) { if (model.isPressed() && model.isArmed()) { g.setColor(MetalLookAndFeel.getControlShadow()); g.fillRect(x, y, controlSize - 1, controlSize - 1); drawPressed3DBorder(g, x, y, controlSize, controlSize); } else { drawFlush3DBorder(g, x, y, controlSize, controlSize); } g.setColor(MetalLookAndFeel.getControlInfo()); } else { g.setColor(MetalLookAndFeel.getControlShadow()); g.drawRect(x, y, controlSize - 1, controlSize - 1); } if (drawCross) { drawCross(c, g, x, y); } if (drawCheck) { if (cb.isBorderPaintedFlat()) { x++; } drawCheck(c, g, x, y); } }// paintIcon protected void drawCross(Component c, Graphics g, int x, int y) { int controlSize = getControlSize(); g.drawLine(x + (controlSize - 4), y + 2, x + 3, y + (controlSize - 5)); g.drawLine(x + (controlSize - 4), y + 3, x + 3, y + (controlSize - 4)); g.drawLine(x + 3, y + 2, x + (controlSize - 4), y + (controlSize - 5)); g.drawLine(x + 3, y + 3, x + (controlSize - 4), y + (controlSize - 4)); } protected void drawCheck(Component c, Graphics g, int x, int y) { int controlSize = getControlSize(); g.fillRect(x + 3, y + 5, 2, controlSize - 8); g.drawLine(x + (controlSize - 4), y + 3, x + 5, y + (controlSize - 6)); g.drawLine(x + (controlSize - 4), y + 4, x + 5, y + (controlSize - 5)); } private void drawFlush3DBorder(Graphics g, int x, int y, int w, int h) { g.translate(x, y); g.setColor(MetalLookAndFeel.getControlDarkShadow()); g.drawRect(0, 0, w - 2, h - 2); g.setColor(MetalLookAndFeel.getControlHighlight()); g.drawRect(1, 1, w - 2, h - 2); g.setColor(MetalLookAndFeel.getControl()); g.drawLine(0, h - 1, 1, h - 2); g.drawLine(w - 1, 0, w - 2, 1); g.translate(-x, -y); } private void drawPressed3DBorder(Graphics g, int x, int y, int w, int h) { g.translate(x, y); drawFlush3DBorder(g, 0, 0, w, h); g.setColor(MetalLookAndFeel.getControlShadow()); g.drawLine(1, 1, 1, h - 2); g.drawLine(1, 1, w - 2, 1); g.translate(-x, -y); } public int getIconWidth() { return getControlSize(); } public int getIconHeight() { return getControlSize(); } } }

Hi All,
I've always been curious about the term "engine" that we use in computer software. We often hear a "Database Engine" or a "Search Engine". My question is, what is really called an "Engine"?
Is it just a term to describe how complicated and intricate an algorithm is? Or are there some particular specifications that the algorithm should have so we can call it an "engine"?

Best regards,