Jython
 
 

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In the last couple of years small and cheap moving robots containing a microprocessor brick are extensively used in the class room. They promote a modern aspect of our technical society and the engineering way of thinking for the constructing a concrete robot designed to perform a predefined task as well as for writing programs to make the robot accomplish that particular task. Using robots can be so much fun in the class room that kids are not even aware they are learning!

One of the most widespread educational robot is Lego NXT and the new Lego EV3. The NXT brick can be programmed to run autonomously using a few specific languages, among them graphical based languages (LabVIEW and the like), C and Java. The robot can also be controlled by sending commands over Bluetooth from a PC running any programming language. The NxtJLib/EV3Lib libraries developed for Java have a pure object-oriented design using the classical event callback model. The libraries are used in many Java programming courses and have been included in the TigerJython distribution.

Installation for NXT:
Copy into the Lib subdirectory of the directory where tigerjython2.jar resides:
under Windows: bluecove.2-1-1.jar (download)
under Linux/Mac: bluecove-gpl-2.1.1-SCNAPSHOT.jar (download)

This site emphasizes the Lego NXT brick used in direct mode. To learn how to use the new EV3 robot in direct or autonomous mode, consult the EV3JLIB Website here.

Example 1: Purpose: Learn the fundamental concept of NxtJLib.

A robot instance is created and the Bluetooth link established. Then two motors are created and assembled into to robot. Hereafter the robot is used. In the end the robot is disconnected and the program terminates.

Error Page

Error Page

Stack trace:

java.io.FileNotFoundException: The requested resource [/home/pyincludes/NxtEx1.html] is not available
	at org.apache.catalina.servlets.DefaultServlet.serveResource(DefaultServlet.java:845)
	at org.apache.catalina.servlets.DefaultServlet.doGet(DefaultServlet.java:497)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
	at org.apache.catalina.servlets.DefaultServlet.service(DefaultServlet.java:477)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	at sun.reflect.GeneratedMethodAccessor65.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:282)
	at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:279)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAsPrivileged(Subject.java:549)
	at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:314)
	at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:170)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:225)
	at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:47)
	at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:149)
	at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:145)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:712)
	at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:580)
	at org.apache.catalina.core.ApplicationDispatcher.access$100(ApplicationDispatcher.java:64)
	at org.apache.catalina.core.ApplicationDispatcher$PrivilegedInclude.run(ApplicationDispatcher.java:113)
	at org.apache.catalina.core.ApplicationDispatcher$PrivilegedInclude.run(ApplicationDispatcher.java:101)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:507)
	at org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:955)
	at org.apache.jsp.jython_005fex3_jsp._jspService(jython_005fex3_jsp.java:170)
	at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:71)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:477)
	at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:385)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:329)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	at sun.reflect.GeneratedMethodAccessor65.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:282)
	at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:279)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAsPrivileged(Subject.java:549)
	at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:314)
	at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:170)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:225)
	at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:47)
	at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:149)
	at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:145)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:712)
	at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:580)
	at org.apache.catalina.core.ApplicationDispatcher.access$100(ApplicationDispatcher.java:64)
	at org.apache.catalina.core.ApplicationDispatcher$PrivilegedInclude.run(ApplicationDispatcher.java:113)
	at org.apache.catalina.core.ApplicationDispatcher$PrivilegedInclude.run(ApplicationDispatcher.java:101)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:507)
	at org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:955)
	at org.apache.jsp.printcenter_jsp._jspService(printcenter_jsp.java:157)
	at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:71)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:477)
	at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:385)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:329)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	at sun.reflect.GeneratedMethodAccessor65.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:282)
	at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:279)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAsPrivileged(Subject.java:549)
	at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:314)
	at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:170)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:225)
	at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:47)
	at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:149)
	at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:145)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	at sun.reflect.GeneratedMethodAccessor64.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:282)
	at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:279)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAsPrivileged(Subject.java:549)
	at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:314)
	at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:253)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:191)
	at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:47)
	at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:149)
	at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:145)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
	at org.apache.coyote.ajp.AjpProcessor.service(AjpProcessor.java:432)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)

Request URL:

http://www.aplu.ch/home/printcenter.jsp

Parameters:

    center_to_include: jython_ex3.jsp