How to reconfigure logger (log4j2) with a java.util.Properties object created from a string?

Question

Migrating from log4j to log4j2. Previously, the following function is called, after creating the Logger object.

public static void getLog4JSettingsFromString(String configString) throws IOException {
    Properties log4j = new java.util.Properties();
    log4j.load(new ByteArrayInputStream(configString.getBytes()));
    PropertyConfigurator.configure(log4j);
}

Hi Please have a look of this thread https://stackoverflow.com/questions/2288876/how-to-configure-log4j-with-a-properties-file — Raushan Kumar, Jan 07 '22 at 14:56
Hi, that is for log4j 1.x, the code I have is for that and it works fine. What I need is a solution for the same problem on log4j 2.x. — Manoj Kommineni, Jan 07 '22 at 15:16

score 0 · Answer 1 · answered Jan 07 '22 at 16:58

To configure Log4j 2.x you need to obtain a Configuration from a ConfigurationFactory:

final InputStream is = new ByteArrayInputStream(configString);
final LoggerContext context = LoggerContext.getContext(false);
final ConfigurationSource source = new ConfigurationSource(is);
final Configuration config = new PropertiesConfigurationFactory().getConfiguration(context, source);
Configurator.reconfigure(config);

There are two factories named PropertiesConfigurationFactory:

one that supports the Log4j 2.x configuration syntax:

import org.apache.logging.log4j.core.config.properties.PropertiesConfigurationFactory;

one that supports (a subset of) the Log4j 1.x configuration syntax:
```
import org.apache.log4j.config.PropertiesConfigurationFactory;
```
and requires the log4j-1.2-api dependency.

How to reconfigure logger (log4j2) with a java.util.Properties object created from a string?

1 Answers1