Java Helpdesk All your queries regarding Java Programming goes here.

Hellow friends,I am creating this thread for all queries and suggestions related to java coding. If you face any problem, post it here, and others who have a solution can post the reply here. Hope it helps the users.

do you know JINI i've some problems in it can you help.

Hi guys i have a little problem here!. I've just download the Java Development Kit (JDK 1.6 BETA 2) for Linux. My Problem is how to integrate any java application like *.java *.jar with the java binaries that i've extracted. I'm newbie for linux. I'm using Ubuntu Dapper Drake (6.06).For now i just make symbolic link to /usr/bin from my java's bin/java directory. And every time I need execute my jar file. I always use terminal to run it. I've tried to right click and try to open with java binaries file. And some error occured says "Cound not add application to application database!". Err...!!Anyone can help please??

where is a good site to get tutorials on java?

It all depends on what type of Java you are talking about. J2SE or J2ME, but my guess is J2SE because not many people program using J2ME. You can try going to Java Sun forums. They provide a lot of good solutions for you. Just by browsing the forum, you learn a lot of new things. Trust me on that because I have learnt quite some stuff from there. However their J2ME forum is a little quiet, I am just surprised why there are not many people talking about programming on the mobile. After all thats where the industry is heading.

How to run a java file from another java file?

Java Helpdesk

 

Hi! I want to run a java file from another java file. I heard exec() method from Rumtime class. I wrote two files(Caller and Hello) for testing. Following codes:

 

Caller.Java

Import java.Io.*;

Public class Caller{

Public static void main(String args[]) throws Exception{

Runtime rt = Runtime.GetRuntime();

Process prcs = rt.Exec("java Hello");

 

Hello.Java

Import java.Lang.System;

Public class Hello{

Public static void main(String args[]){

System.Out.Println("Hello World.");

}

}

 

Although I compile and run successfully but I didn't get result I neeed (printing Hello World). Please help me! Thanks so much!

 

-question by thungphan

How to run a java file from another java file?

 

Java Helpdesk

Hi! I want to run a java file from another java file. I heard exec() method from Rumtime class. I wrote two files(Caller and Hello) for testing. Following codes:

 

Caller.Java

Import java.Io.*;

Public class Caller{

Public static void main(String args[]) throws Exception{

Runtime rt = Runtime.GetRuntime();

Process prcs = rt.Exec("java Hello");

 

Hello.Java

Import java.Lang.System;

Public class Hello{

Public static void main(String args[]){

System.Out.Println("Hello World.");

}

}

 

Although I compile and run successfully but I didn't get result I neeed (printing Hello World). Please help me! Thanks so much!

 

-question by thungphan

The Runtime.exec methods create a native process and return an instance of a subclass of Process that can be used to control the process and obtain information about it.

So if you want to get the output ("Hello World"), you need to use Process.getInputStream() method.

 

The method will return an InputStream, which you can use to generate output in your monitor.

 

This is the example of how to print the InputStream:

InputStream is = process.getInputStream();BufferedReader is = new BufferedReader(new InputStreamReader(is));	String line;	while ((line = is.readLine()) != null)	  System.out.println(line);

Code for HR Help Desk in java

Java Helpdesk

 

I need code for HR help desk. I am unable to coding for this project. I have no time. Please help me

 

-reply by Raviteja

where is a good site to get tutorials on java?

java2s.com - really good examples for very beginners and beyond

Object following a mouse path in JavaJava Helpdesk

Hello all. Is it possible to select a slowly moving object (with a mouse), then draw a visible path from the selected object to a stationary point (point with the mouse, then (either mouse click again or let mouse button up) to hide the path and have the object keep following the (now invisible) path to point B. When the object reaches point B it will disappear. The path between the selected object and point B will not necessary be a straight line, but may be a series of curves. Hopefully I can do multiple instances of other selected objects to point B simultaneously! Any help greatly appreciated

-question by Daryl

 

Yes, it is very possible. Just implement the path of the ball as a queue of locations to go to. With an empty queue, it would move randomly. Use mouse events to track the path of the mouse through the canvas. Then, take all those coordinates and add them to the queue for the ball. Since the queue is no longer empty, it will start to follow that path, discarding the front of the queue with each successful move operation.Things that can be added: interpolation so that the moves are smooth in case mouse events are not being reported properly. Automatic path finding so that if the path goes through a gap between obstacles that is not large enough for the ball, it searches for an alternate path (using A* or some other algorithm). Regards,z.