Java tutorial
import java.util.logging.Filter; import java.util.logging.Level; import java.util.logging.LogRecord; import java.util.logging.Logger; class Person { private String name = null; private int age; public Person(String name, int age) { this.name = name; this.age = age; } public void setName(String name) { this.name = name; } public String getName() { return name; } public void setAge(int age) { this.age = age; } public int getAge() { return age; } } class AgeFilter implements Filter { public boolean isLoggable(LogRecord record) { boolean result = false; Object[] objs = record.getParameters(); Person person = (Person) objs[0]; if (person != null) { int age = person.getAge(); if (age > 30) result = true; else result = false; } return result; } } public class Main { public static void main(String args[]) { Logger logger = Logger.getLogger("your.logging"); AgeFilter filter = new AgeFilter(); logger.setFilter(filter); Person person = new Person("YourName", 32); logger.log(Level.INFO, "Person has age " + person.getAge(), person); } }