jul-jsonformatter

Formatter to log java.util.logging(JUL) messages as JSON, compatible with Logstash

Usage

• Include the dependency

For Maven:

<dependency>
    <groupId>io.github.devatherock</groupId>
    <artifactId>jul-jsonformatter</artifactId>
    <version>1.1.0</version>
</dependency>

For Gradle:

compile group: 'io.github.devatherock', name: 'jul-jsonformatter', version: '1.1.0'

• Include any one of Gson, Jackson or json-simple libraries in classpath
• Include a logging.properties file in classpath with io.github.devatherock.json.formatter.JSONFormatter as the formatter

handlers=java.util.logging.ConsoleHandler

java.util.logging.ConsoleHandler.level=INFO
java.util.logging.ConsoleHandler.formatter=io.github.devatherock.json.formatter.JSONFormatter

The path to the logging.properties file can also be passed as JVM arg like -Djava.util.logging.config.file=/path/to/logging.properties

Change key names

You can change the key names using the configuration file logging.properties
The following is an example with the default key names:

io.github.devatherock.json.formatter.JSONFormatter.key_timestamp=@timestamp
io.github.devatherock.json.formatter.JSONFormatter.key_logger_name=logger_name
io.github.devatherock.json.formatter.JSONFormatter.key_log_level=level
io.github.devatherock.json.formatter.JSONFormatter.key_thread_name=thread_name
io.github.devatherock.json.formatter.JSONFormatter.key_logger_class=class
io.github.devatherock.json.formatter.JSONFormatter.key_logger_method=method
io.github.devatherock.json.formatter.JSONFormatter.key_message=message
io.github.devatherock.json.formatter.JSONFormatter.key_exception=exception

Use slf4j log level names

Change the log level names using the same mapping as SLF4JBridgeHandler:

FINEST  -> TRACE
FINER   -> DEBUG
FINE    -> DEBUG
INFO    -> INFO
CONFIG  -> CONFIG
WARNING -> WARN
SEVERE  -> ERROR

Set the following in the logging.properties file to change the log level names:

io.github.devatherock.json.formatter.JSONFormatter.use_slf4j_level_names=true

Samples

Each line in the generated log will be a JSON. Sample one line message:

{
    "@timestamp": "2018-09-30T08:00:17.632-05:00",
    "logger_name": "io.github.devatherock.json.formatter.helpers.GSONFormatterTest",
    "level": "INFO",
    "thread_name": "Test worker",
    "class": "io.github.devatherock.json.formatter.helpers.GSONFormatterTest",
    "method": "testSimpleMessage",
    "message": "First message"
}

Multi-line message:

{
    "@timestamp": "2018-09-30T08:00:17.654-05:00",
    "logger_name": "io.github.devatherock.json.formatter.helpers.GSONFormatterTest",
    "level": "INFO",
    "thread_name": "Test worker",
    "class": "io.github.devatherock.json.formatter.helpers.GSONFormatterTest",
    "method": "testMessageWithNewLine",
    "message": "Next message\n"
}

Message with exception:

{
    "@timestamp": "2018-09-30T08:33:58.394-05:00",
    "logger_name": "io.github.devatherock.json.formatter.helpers.GSONFormatterTest",
    "level": "SEVERE",
    "thread_name": "Test worker",
    "class": "io.github.devatherock.json.formatter.helpers.GSONFormatterTest",
    "method": "testMessageWithExceptionWithExceptionMessage",
    "message": "Test message with exception",
    "exception": {
        "exception_class": "java.lang.RuntimeException",
        "exception_message": "test exception",
        "stack_trace": "java.lang.RuntimeException: test exception\n\tat com.devaprasadh.json.formatter.helpers.GSONFormatterTest.testMessageWithExceptionWithExceptionMessage(GSONFormatterTest.java:115)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)\n\tat sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\n\tat java.lang.reflect.Method.invoke(Method.java:498)\n\tat org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)\n\tat org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)\n\tat org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)\n\tat org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)\n\tat org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)\n\tat org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)\n\tat org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)\n\tat org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)\n\tat org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)\n\tat org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)\n\tat org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)\n\tat org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)\n\tat org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)\n\tat org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)\n\tat org.junit.runners.ParentRunner.run(ParentRunner.java:363)\n\tat org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.runTestClass(JUnitTestClassExecutor.java:106)\n\tat org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:58)\n\tat org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:38)\n\tat org.gradle.api.internal.tasks.testing.junit.AbstractJUnitTestClassProcessor.processTestClass(AbstractJUnitTestClassProcessor.java:66)\n\tat org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:51)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)\n\tat sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\n\tat java.lang.reflect.Method.invoke(Method.java:498)\n\tat org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35)\n\tat org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)\n\tat org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:32)\n\tat org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:93)\n\tat com.sun.proxy.$Proxy2.processTestClass(Unknown Source)\n\tat org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:109)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)\n\tat sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\n\tat java.lang.reflect.Method.invoke(Method.java:498)\n\tat org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35)\n\tat org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)\n\tat org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:155)\n\tat org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:137)\n\tat org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:404)\n\tat org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)\n\tat org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)\n\tat java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)\n\tat java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)\n\tat org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)\n\tat java.lang.Thread.run(Thread.java:748)\n"
    }
}