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18 package org.apache.log4j.spi;
20 import org.apache.log4j.Level;
21 import org.apache.log4j.Logger;
22 import org.apache.log4j.helpers.LogLog;
25 // Contibutors: Mathias Bogaert
28 RootLogger sits at the top of the logger hierachy. It is a
29 regular logger except that it provides several guarantees.
31 <p>First, it cannot be assigned a <code>null</code>
32 level. Second, since root logger cannot have a parent, the
33 {@link #getChainedLevel} method always returns the value of the
34 level field without walking the hierarchy.
36 @author Ceki Gülcü
39 public final class RootLogger extends Logger {
41 The root logger names itself as "root". However, the root
42 logger cannot be retrieved by name.
44 public RootLogger(Level level) {
50 Return the assigned level value without walking the logger
53 public final Level getChainedLevel() {
58 Setting a null value to the level of the root logger may have catastrophic
59 results. We prevent this here.
62 public final void setLevel(Level level) {
65 "You have tried to set a null level to root.", new Throwable());