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running a java program

Prahlad Joshi
Ranch Hand

Joined: Apr 21, 2007
Posts: 44
i want to run a package containing .class files from a java program for this i have written:
Process tempProcess=Runtime.getRuntime().exec("java "+ mainClassName,null,new;
but the problem is that i am not able to given input to this tempProcess or see output of it.
Ulf Dittmer

Joined: Mar 22, 2005
Posts: 42958
That code may produce some output or need some input that your code isn't handling. See this article for pitfalls to avoid when using Runtime.exec.
Kelvin Chenhao Lim
Ranch Hand

Joined: Oct 20, 2007
Posts: 513
Aside from the issues that Ulf pointed out, are you also sure you want to start a new JVM to run your sub-application? Depending on exactly what you want to achieve, you may find the Reflection API more useful and appropriate. Things get slightly complicated if the .class files aren't already in your current classpath (you may need to create a new class loader), but this may still be better than using Runtime.exec().

SCJP 5.0
I agree. Here's the link:
subject: running a java program
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