How to set Spring Boot's logging levels programmatically?

Question

I know how to set the log level via environment variables and application properties.

Is there a way to set them programmatically?

I would like to set log levels for particular test classes (which are using SpringJUnit4ClassRunner and @SpringApplicationConfiguration), but not all of them, and without having a separate properties file for every combination.

I tried defining a non-lazy bean to add a new PropertySource to the environment; the method was called but it had no effect.

@Bean
@Lazy(false)
public PropertySource testProperties(ConfigurableEnvironment environment) {
  PropertySource properties = new MapPropertySource("testProperties", Collections.singletonMap(
      "logging.level.org.springframework.security", "DEBUG"
  ));

  environment.getPropertySources().addFirst(properties);
  return properties;
}

The only way I know of configured log levels once the logger has been started is via JMX... — Boris the Spider, Feb 11 '16 at 17:42
@BoristheSpider That's only available for `java.util.logging`, which spring-boot doesn't use. — OrangeDog, Feb 11 '16 at 17:48
Not true on both counts - Logback and Log4j2 both support JMX and Spring Boot supports JUL if you want it to (but why the hell would you...). You just need to configure the JMX connector in the config file. You don't say which framework you plugged Boot into. — Boris the Spider, Feb 11 '16 at 17:49
Bingo. Though I was hoping there was a way to change the properties before the context starts up. — OrangeDog, Feb 11 '16 at 17:55

score 5 · Accepted Answer · answered Feb 11 '16 at 20:10

You can use @TestPropertySource on your test classes. Unlike the bean-based approach that you tried, @TestPropertySource will add the property source to the environment before the context starts which allows the properties to be picked up when the logging system is initialized.

Something like this:

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(YourApplication.class)
@TestPropertySource(properties = "logging.level.org.springframework.security:DEBUG")
public class YourApplicationTests {
    // …
}

this didnt work for me, I am creating a spring boot library which does not have main springboot application and therefore everything has to be loaded from test class. and somehow I am not able to disable/change logging — Manish Bansal, Aug 06 '19 at 16:56

score 1 · Answer 2 · edited May 23 '17 at 12:23

Credit to Boris the Spider for the hints.

First, add an element <jmxConfigurator /> to the logback.xml.

Then, this code will work:

@Before
public void configureLogging() throws JMException {
    ObjectName name = new ObjectName(String.format("ch.qos.logback.classic:Name=default,Type=%s", JMXConfigurator.class.getName()));
    JMXConfiguratorMBean logbackMBean = JMX.newMBeanProxy(ManagementFactory.getPlatformMBeanServer(), name, JMXConfiguratorMBean.class);
    logbackMBean.setLoggerLevel("org.springframework.security", "DEBUG");
}

Sadly, there doesn't appear to be a better way to build the object name: the Package hierarchy isn't traversable and the string "default" isn't accessible anywhere I can find.

I really should have thought of one of these first: http://stackoverflow.com/q/7967165/476716 — OrangeDog, Feb 11 '16 at 23:37

How to set Spring Boot's logging levels programmatically?

2 Answers2