Question on Thread.currentThread()

[Kruzer]

I'm experiencing periodically a difference in the number of digits return when calling

Thread thr = Thread.currentThread();
thr.hashcode();

Sometimes the returned value is a 7 or 6 digit number, is there a way to always convert the "thr" value to be an 8 digit number? What do you think of toOctalString(int i)?


I tried something like this to possible eliminate the problem, but I don't think this effective.

int threadValue = 0;
int condition = thr.hashCode() - 10000000;
if (condition < -1) {
// in the event a hascode returns a 7 digit number
threadValue = (thr.hashCode() * 10);
} else {
threadValue = thr.hashCode();
}

Thanks in advance!


Dano
dan_kryzer@hotmail.com
What's your major malfunction

 

[sedj]

Why do you need an 8 digit number ? It makes no sense to me ... the hasCode is there to help in identifying the uniqueness of an object :

/**
* Returns a hash code value for the object. This method is
* supported for the benefit of hashtables such as those provided by
* <code>java.util.Hashtable</code>.
* <p>
* The general contract of <code>hashCode</code> is:
* <ul>
* <li>Whenever it is invoked on the same object more than once during
* an execution of a Java application, the <tt>hashCode</tt> method
* must consistently return the same integer, provided no information
* used in <tt>equals</tt> comparisons on the object is modified.
* This integer need not remain consistent from one execution of an
* application to another execution of the same application.
* <li>If two objects are equal according to the <tt>equals(Object)</tt>
* method, then calling the <code>hashCode</code> method on each of
* the two objects must produce the same integer result.
* <li>It is <em>not</em> required that if two objects are unequal
* according to the {@link java.lang.Object#equals(java.lang.Object)}
* method, then calling the <tt>hashCode</tt> method on each of the
* two objects must produce distinct integer results. However, the
* programmer should be aware that producing distinct integer results
* for unequal objects may improve the performance of hashtables.
* </ul>
* <p>
* As much as is reasonably practical, the hashCode method defined by
* class <tt>Object</tt> does return distinct integers for distinct
* objects. (This is typically implemented by converting the internal
* address of the object into an integer, but this implementation
* technique is not required by the
* Java<font size="-2">^TM</font> programming language.)
*
* @return a hash code value for this object.
* @see java.lang.Object#equals(java.lang.Object)
* @see java.util.Hashtable
*/

 

[Kruzer]

The reason is because I have a listening program that expects files to be in an 8 digit format (i.e. 12345678somemethod.txt). I wrote the receive program to expect an 8 digit number for uniqueness. Some how, some way I would like to I guess pad digits to number that are less than 8 digits. With a give or take of 100+ threads being spawned off.

Dano
dan_kryzer@hotmail.com
What's your major malfunction

 

[sedj]

That seems a little inflexible if you ask me, but anyway ...

		String hc = whatever.hashCode() +"";

		int len = hc.length();
		String tmp = "";
		for (int i = len; i < 8; i++) {
			tmp += "0";
		}

		hc = tmp +hc;
		System.err.println(hc);

 

[sedj]

Actually I suppose incase your hashcode is over 8 digits :

		String hc = new Object().hashCode() +"";
		//String hc = args[0];
		if (hc.length() > 8) {
			hc = hc.substring(0, 8);
		} else {
			int len = hc.length();
			String tmp = "";
			for (int i = len; i < 8; i++) {
				tmp += "0";
			}

			hc = tmp +hc;

		}

		System.err.println(hc);

But if you do substring it, I wouldn't bet on it being unique ...