Echopraxia

Echopraxia is a Java logging API designed around structured logging, rich context, and conditional logging. There are Logback and Log4J2 implementations, but Echopraxia's API is completely dependency-free, meaning it can be implemented with any logging API, i.e. jboss-logging, JUL, JEP 264, or even directly.

What this means is that all arguments in a logging statement have a name and a value, for example:

logger.info("arg1 is {} and arg2 is {}", fb -> fb.list(
  fb.string("name", "value"),
  fb.number("age", 13)
));

writes out in logfmt as:

INFO 13.232 arg1 is name=value and arg2 is age=13

and in a JSON format as:

{
  "message": "arg1 is name=value and arg2 is age=13",
  "name": "value",
  "age": 13
}

What makes Echopraxia effective -- especially for debugging -- is that you can define your own mappings, and then pass in your own objects and render complex objects. For example, we can render a Person object:

Logger<PersonFieldBuilder> logger = LoggerFactory.getLogger(getClass()).withFieldBuilder(PersonFieldBuilder.instance());

Person abe = new Person("Abe", 1, "yodelling");
abe.setFather(new Person("Bert", 35, "keyboards"));
abe.setMother(new Person("Candace", 30, "iceskating"));

logger.info("{}", fb -> fb.person("abe", abe));

And print out the internal state of the Person in both logfmt and JSON.

INFO 13.223 abe={Abe, 1, father={Bert, 35, father=null, mother=null, interests=[keyboards]}, mother={Candace, 30, father=null, mother=null, interests=[iceskating]}, interests=[yodelling]}

Examples

For the fastest possible way to try out Echopraxia, download and run the JBang script.

Simple examples and integrations with dropwizard metrics and OSHI are available at echopraxia-examples.

For a web application example, see this Spring Boot Project.

Scala API

There is a Scala API available at https://github.com/tersesystems/echopraxia-plusscala.