private ConstraintPlugins() {

        final PluginManager manager = new PluginManager(ConstraintType.CATEGORY);
        if (LOGGER instanceof org.apache.logging.log4j.core.Logger) {
            List<String> pluginPackages =
                    ((org.apache.logging.log4j.core.Logger) LOGGER).getContext().getConfiguration().getPluginPackages();
            manager.collectPlugins(pluginPackages);
        } else {
            manager.collectPlugins();
        }
        final Map<String, PluginType<?>> plugins = manager.getPlugins();
        for (Map.Entry<String, PluginType<?>> entry : plugins.entrySet()) {
            try {
                final Class<? extends ConstraintType> clazz = entry.getValue().getPluginClass().asSubclass(ConstraintType.class);
                ConstraintType constraintType = ReflectionUtil.instantiate(clazz);
                constraintMap.put(entry.getKey(), constraintType);
            } catch (final Throwable t) {
                throw new ConstraintCreationException("Unable to create constraint for " + entry.getKey(), t);
            }
        }
    }
 

@BeforeClass
public static void setUp() {
    PluginManager.addPackage("com.baeldung.logging.log4j2.xmlconfiguration");
}
 

@BeforeClass
public static void setUp() {
    PluginManager.addPackage("com.baeldung.logging.log4j2.simpleconfiguration");
}
 

/**
 * Load logging plugins so we can have {@code node_name} in the pattern.
 */
public static void loadLog4jPlugins() {
    PluginManager.addPackage(LogConfigurator.class.getPackage().getName());
}
 

public BuilderManager() {
    final PluginManager manager = new PluginManager(CATEGORY);
    manager.collectPlugins();
    plugins = manager.getPlugins();
}
 

@Test
public void testPlugin(){
	
	PluginManager pm = new PluginManager(PatternConverter.CATEGORY);
	pm.collectPlugins();
	for(Entry<String, PluginType<?>> entry : pm.getPlugins().entrySet()){
		
		logger.info("{} : {}", entry.getKey(), entry.getValue());
		
	}
	
	logger.error("[testPlugin]", new IOException("io exception message..."));
}