如何通过Spring Boot应用程序中的application.properties禁用WARN消息并仅在日志中启用INFO消息？

Question

I have tried using the below property value in my application.properties to enable only logger INFO messages. But looks like it does not work as expected. I still see the WARNING messages appear along with INFO messages. But I only want INFO messages to appear, am I doing something wrong here?

logging.level.root=INFO

2018-12-21 09:46:25.312  INFO 12364 --- [nio-8081-exec-2] c.m.s.abc.util.FileUploadUtil      : Sample message 1
2018-12-21 09:46:25.316  INFO 12364 --- [nio-8081-exec-2] c.m.service.abc.util.EnvelopeUtil  : Sample message 2
2018-12-21 09:46:25.316  INFO 12364 --- [nio-8081-exec-2] c.m.service.abc.util.EnvelopeUtil  : Sample message 3
2018-12-21 09:46:25.316  INFO 12364 --- [nio-8081-exec-2] c.m.service.abc.util.EnvelopeUtil  : Sample message 4
2018-12-21 09:46:27.813  WARN 12364 --- [nio-8081-exec-2] o.a.pdfbox.pdmodel.font.PDType0Font      : No Unicode mapping for CID+11 (11) in font ArialNarrow-Bold-Identity-H
2018-12-21 09:46:27.813  WARN 12364 --- [nio-8081-exec-2] o.a.pdfbox.pdmodel.font.PDType0Font      : No Unicode mapping for CID+48 (48) in font ArialNarrow-Bold-Identity-H
2018-12-21 09:46:27.813  WARN 12364 --- [nio-8081-exec-2] o.a.pdfbox.pdmodel.font.PDType0Font      : No Unicode mapping for CID+68 (68) in font ArialNarrow-Bold-Identity-H
2018-12-21 09:46:27.813  WARN 12364 --- [nio-8081-exec-2] o.a.pdfbox.pdmodel.font.PDType0Font      : No Unicode mapping for CID+86 (86) in font ArialNarrow-Bold-Identity-H
2018-12-21 09:46:27.814  WARN 12364 --- [nio-8081-exec-2] o.a.pdfbox.pdmodel.font.PDType0Font      : No Unicode mapping for CID+88 (88) in font ArialNarrow-Bold-Identity-H
2018-12-21 09:46:27.814  WARN 12364 --- [nio-8081-exec-2] o.a.pdfbox.pdmodel.font.PDType0Font      : No Unicode mapping for CID+87 (87) in font ArialNarrow-Bold-Identity-H

Answer 1

You're not doing anything wrong, but none of the logging systems supported by Spring Boot (Logback, Log4j2, JUL) work as you expect. When you set the level for a particular logger, it will log everything at that level and above. As you have seen, that means that when INFO level logging is enabled, WARN (and ERROR ) messages will also be logged.

If you want to only log messages for a specific level, you'll have to use more complex configuration. For example, Logback provides a LevelFilter that provides the behaviour you want. To configure it, you'll have to use logback.xml rather than relying solely on Spring Boot's application properties.