#28 Doubly called PropertyConfigurator differs from log4j

[Park Il]

When I called PropertyConfigurator.configure() twice with the same properties file, all the appenders are also doubled. So that all log messages are doubled!

I tested the same thing with log4j with below code, and it gave me only one log entry.

import java.util.*;

import org.apache.log4j.*;

public class DoubleConfigure {
    public static void main(String[] args) throws  Exception {
        Properties properties = new Properties();
        properties.put("log4j.rootLogger", "ALL, R");
        properties.put("log4j.appender.R", "org.apache.log4j.ConsoleAppender");
        properties.put("log4j.appender.R.layout",
            "org.apache.log4j.PatternLayout");
        properties.put("log4j.appender.R.layout.ConversionPattern",
            "%d [%t] %-5p %c{1} - %m%n");
        PropertyConfigurator.configure(properties);
        PropertyConfigurator.configure(properties);
        Logger logger = Logger.getLogger("Logger");
        logger.debug("TEST!");
    }
}

[David Whetstone]

Logged In: YES
user_id=989860

This is an important one, as it prevents you from properly re-configuring
a system. You can't remove appenders from a logger via the config files.
That's not good. I'm going to need to fix this myself for our product. I'll
submit my suggested changes when I do - Unless someone's already
working on it. Anyone... Anyone...

[David Whetstone]

Logged In: YES
user_id=989860

This is an important one, as it prevents you from properly re-configuring
a system. You can't remove appenders from a logger via the config files.
That's not good. I'm going to need to fix this myself for our product. I'll
submit my suggested changes when I do - Unless someone's already
working on it. Anyone... Anyone...

[Václav Haisman]

Have you fixed it in your product? If you have, could you share the fix?

I have looked into the code and it seems that adding call to removeAllAppenders() right before the loop that calls addAppend() in PropertyConfigurator::configureLogger() is the right fix.

[Václav Haisman]

I have committed the suggested fix in revision 660 on the PRODUCTIN_1_0_x branch. It will be part of the next release candidate.

[Václav Haisman]

• Description has changed:

Diff:

--- old
+++ new
@@ -1,31 +1,25 @@
-When I called PropertyConfigurator.configure\(\) twice 
-with the same properties file, all the appenders are also 
-doubled.
-So that all log messages are doubled\!
+When I called `PropertyConfigurator.configure()` twice with the same properties file, all the appenders are also doubled. So that all log messages are doubled!

-I tested the same thing with log4j with below code, and 
-it gave me only one log entry.
+I tested the same thing with log4j with below code, and it gave me only one log entry.

-import java.util.\*;
+~~~~
+import java.util.*;

-import org.apache.log4j.\*;
+import org.apache.log4j.*;

-public class DoubleConfigure \{
-public static void main\(String\[\] args\) throws 
-Exception \{
-Properties properties = new Properties\(\);
-properties.put\("log4j.rootLogger", "ALL, R"\);
-properties.put
-\("log4j.appender.R", "org.apache.log4j.ConsoleAppender"\)
-;
-properties.put\("log4j.appender.R.layout",
-"org.apache.log4j.PatternLayout"\);
-properties.put
-\("log4j.appender.R.layout.ConversionPattern",
-"%d \[%t\] %-5p %c\{1\} - %m%n"\);
-PropertyConfigurator.configure\(properties\);
-PropertyConfigurator.configure\(properties\);
-Logger logger = Logger.getLogger\("Logger"\);
-logger.debug\("TEST\!"\);
-\}
-\}
+public class DoubleConfigure {
+    public static void main(String[] args) throws  Exception {
+        Properties properties = new Properties();
+        properties.put("log4j.rootLogger", "ALL, R");
+        properties.put("log4j.appender.R", "org.apache.log4j.ConsoleAppender");
+        properties.put("log4j.appender.R.layout",
+            "org.apache.log4j.PatternLayout");
+        properties.put("log4j.appender.R.layout.ConversionPattern",
+            "%d [%t] %-5p %c{1} - %m%n");
+        PropertyConfigurator.configure(properties);
+        PropertyConfigurator.configure(properties);
+        Logger logger = Logger.getLogger("Logger");
+        logger.debug("TEST!");
+    }
+}
+~~~~