Thursday, February 25, 2010

Java Application Memory utilization

java -jar -Xms64m -Xmx128m Test.jar

When running your java application, use above arguments. This will allocate 64MB minimum for your application and 128MB maximum. If 128MB exceeds, java will call the garbage collector.

Wednesday, February 10, 2010

Writing console output to a file in java

Use this code to write your console outputs to a file using java.

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.PrintStream;

public class RedirectIO {

public static void main(String[] args) {

PrintStream orgStream = null;
PrintStream fileStream = null;

try {

// Saving the orginal stream
orgStream = System.out;
fileStream = new PrintStream(new FileOutputStream("d:/123.txt",true));

// Redirecting console output to file
System.setOut(fileStream);

// Redirecting runtime exceptions to file
System.setErr(fileStream);

throw new Exception("Test Exception");

}catch (FileNotFoundException fnfEx){
System.out.println("Error in IO Redirection");
fnfEx.printStackTrace();
}catch (Exception ex){
ex.printStackTrace();
//Gets printed in the file
System.out.println("Redirecting output & exceptions to file");
}finally{
//Restoring back to console
System.setOut(orgStream);
//Gets printed in the console
System.out.println("Redirecting file output back to console");
}
}
}

Saturday, February 6, 2010

Stack Trace of the Exception to a String

Use this code inside your catch block. This will return a string.

}catch(Exception e){

StringWriter sWriter = new StringWriter();
e.printStackTrace(new PrintWriter(sWriter));
System.out.println(sWriter.getBuffer().toString()) ;

}

Tuesday, February 2, 2010

Task Manager in Solaris Console

In console type "prstat".

This will show a program looks like windows Task manager.