LogMap

LogMap is an interface to help you easily generate logs in an organized and standard format.

LogMap IS NOT a logging framework. It just build messages to be logged by any logging framework that implements Simple Logging Facade for Java (SLF4J) (e.g. Log4J, Logback, java.util.logging)

Why use LogMap ?

We usually create log messages mixing a static message and some dynamic values:

 logger.error("one two three: {} {} {}", "a", "b","c")

21:31:00.598 [main] ERROR test-logger - one two three: a b c

This is a very easy format for humans to read, but this make difficult to filter values from logs when you are using them as source for reports, monitoring dashboards, bug analysis, etc. This is mainly because the log message has no standard format.

With LogMap, we generate messages in a standard format(key-value pairs), so you can easily extract information from your logs!

L.error("Error! Log it!").add("error_code", 502).log();

21:31:00.598 [main] ERROR test-logger - msg="Error! Log it!", error_code=502

Other benefits:

• Easy to read log messages
• Keep the dynamic data separated from the static message
• Easy and fast way to write and maintain log lines
• Easy to programatically extract log information

Code Example

First, get an instance of the CustomLogger class

private static CustomLogger L = new CustomLogger(MyClassName.class); 

And use it to log your application events:

Log an event passing a message and adding useful info

L.error("Error! Log it!").add("error_code", 502).log();

21:31:00.598 [main] ERROR test-logger - msg="Error! Log it!", error_code=502

You can add as many key/values entries as you want

L.error("Error! Log it!").add("error_code", 502).add("error_message", ex.getMessage()).log();

21:31:00.598 [main] ERROR test-logger - msg="Error! Log it!", error_code=502, error_message="Unexpected exception"

You can also log an object as JSON

L.debug("Logging the User Object as JSON").add("user", userObject).log(); 

21:31:00.598 [main] DEBUG test-logger - msg="Logging the User Object as JSON", user="{id:123, name:"Joe Doe", age:35}"

And an exception stack trace

L.error("Error! See this stack trace").add(myException).log(); 

21:31:00.598 [main] ERROR test-logger - msg="Error! See this stack trace", stacktrace=java.lang.Exception
	at com.github.fcappi.log4splunk.test.NullTest.testNullValues(NullTest.java:48)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)"

Installation

If you use Maven, add LogMap as a dependency in your project including the following lines to your pom.xml:

<dependency>
    <groupId>com.github.trustbox</groupId>
    <artifactId>logmap</artifactId>
    <version>1.5.0</version>
</dependency>

If you use other dependency management tools, see Maven repository - Dependency information

It's also required that you have as your project dependency a logging framework that implements Simple Logging Facade for Java (SLF4J) (e.g. Log4J, Logback, java.util.logging).

Done! Now see the Code Example section to know how easy and useful is to use LogMap!

License

This project is licensed under the GNU GENERAL PUBLIC LICENSE v3 - see the LICENSE.md file for details