// : c15:SimpleFilter.java
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
import java.util.logging.Filter;
import java.util.logging.Level;
import java.util.logging.LogRecord;
import java.util.logging.Logger;
public class SimpleFilter {
private static Logger logger = Logger.getLogger("SimpleFilter");
static class Duck {
};
static class Wombat {
};
static void sendLogMessages() {
logger.log(Level.WARNING, "A duck in the house!", new Duck());
logger.log(Level.WARNING, "A Wombat at large!", new Wombat());
}
public static void main(String[] args) {
sendLogMessages();
logger.setFilter(new Filter() {
public boolean isLoggable(LogRecord record) {
Object[] params = record.getParameters();
if (params == null)
return true; // No parameters
if (record.getParameters()[0] instanceof Duck)
return true; // Only log Ducks
return false;
}
});
logger.info("After setting filter..");
sendLogMessages();
}
} ///:~