src/site/asciidoc/manual/flowtracing.adoc - logging-log4j2 - Git at Google

 ////
     Licensed to the Apache Software Foundation (ASF) under one or more
     contributor license agreements. See the NOTICE file distributed with
     this work for additional information regarding copyright ownership.
     The ASF licenses this file to You under the Apache License, Version 2.0
     (the "License"); you may not use this file except in compliance with
     the License. You may obtain a copy of the License at

         https://www.apache.org/licenses/LICENSE-2.0

     Unless required by applicable law or agreed to in writing, software
     distributed under the License is distributed on an "AS IS" BASIS,
     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     See the License for the specific language governing permissions and
     limitations under the License.
 ////
 = Log4j 2 API
 Ralph Goers <rgoers@apache.org>

 [#FlowTracing]
 == Flow Tracing

 The `Logger` class provides logging methods that are quite useful for
 following the execution path of applications. These methods generate
 logging events that can be filtered separately from other debug logging.
 Liberal use of these methods is encouraged as the output has been found
 to

 * aid in problem diagnosis in development without requiring a debug
 session
 * aid in problem diagnosis in production where no debugging is possible
 * help educate new developers in learning the application.

 The most used methods are the entry() or traceEntry() and exit() or
 traceExit() methods. entry() or traceEntry() should be placed at the
 beginning of methods, except perhaps for simple getters and setters.
 entry() can be called passing from 0 to 4 parameters. Typically these
 will be parameters passed to the method. traceEntry() can be passed a
 format String and a variable list of parameters, or a Message. The
 entry() and traceEntry() methods log with a level of TRACE and uses a
 Marker with a name of "ENTER" which is also a "FLOW" Marker and all
 message strings will begin with "event", even if a format String or
 Message is used.

 The main difference between the entry and traceEntry methods is that the
 entry method accepts a variable list of objects where presumably each is
 a method parameter. The traceEntry method accepts a format string
 followed by a variable list of objects, presumably included in the
 format String. It is not possible to have a single method that includes
 both of these as it would be ambiguous whether the first String is a
 parameter or a format String.

 An exit() or traceExit() method should be placed before any return
 statement or as the last statement of methods without a return. exit()
 and traceExit() can be called with or without a parameter. Typically,
 methods that return void will use exit() or traceExit() while methods
 that return an Object will use exit(Object obj) or traceExit(object, new
 SomeMessage(object)). The exit() and traceExit() methods log with a
 level of TRACE and uses a Marker with a name of "EXIT" which is also a
 "FLOW" Marker and all message strings will begin with "exit", even if a
 format String or Message is used.

 The throwing() method can be used by an application when it is throwing
 an exception that is unlikely to be handled, such as a RuntimeException.
 This will insure that proper diagnostics are available if needed. The
 logging event generated will have a level of ERROR and will have an
 associated Marker with a name of "THROWING" which is also an "EXCEPTION"
 Marker.

 The catching() method can be used by an application when it catches an
 Exception that it is not going to rethrow, either explicitly or attached
 to another Exception. The logging event generated will have a level of
 ERROR and will have an associated Marker with a name of "CATCHING" which
 is also an "EXCEPTION" Marker.

 The following example shows a simple application using these methods in
 a fairly typical manner. The throwing() is not present since no
 Exceptions are explicitly thrown and not handled.

 [source,java]
 ----
 package com.test;

 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.LogManager;

 import java.util.Random;

 public class TestService {
     private Logger logger = LogManager.getLogger(TestService.class.getName());

     private String[] messages = new String[] {
         "Hello, World",
         "Goodbye Cruel World",
         "You had me at hello"
     };
     private Random rand = new Random(1);

     public void setMessages(String[] messages) {
         logger.traceEntry(new JsonMessage(messages));
         this.messages = messages;
         logger.traceExit();
     }

     public String[] getMessages() {
         logger.traceEntry();
         return logger.traceExit(messages, new JsonMessage(messages));
     }

     public String retrieveMessage() {
         logger.entry();

         String testMsg = getMessage(getKey());

         return logger.exit(testMsg);
     }

     public void exampleException() {
         logger.entry();
         try {
             String msg = messages[messages.length];
             logger.error("An exception should have been thrown");
         } catch (Exception ex) {
             logger.catching(ex);
         }
         logger.exit();
     }

     public String getMessage(int key) {
         logger.entry(key);

         String value = messages[key];

         return logger.exit(value);
     }

     private int getKey() {
         logger.entry();
         int key = rand.nextInt(messages.length);
         return logger.exit(key);
     }
 }
 ----

 This test application uses the preceding service to generate logging
 events.

 [source,java]
 ----
 package com.test;

 public class App {

     public static void main( String[] args ) {
         TestService service = new TestService();
         service.retrieveMessage();
         service.retrieveMessage();
         service.exampleException();
     }
 }
 ----

 The configuration below will cause all output to be routed to
 target/test.log. The pattern for the FileAppender includes the class
 name, line number and method name. Including these in the pattern are
 critical for the log to be of value.

 [source,xml]
 ----
 <?xml version="1.0" encoding="UTF-8"?>
 <Configuration status="error">
   <Appenders>
     <Console name="Console" target="SYSTEM_OUT">
       <ThresholdFilter level="ERROR" onMatch="ACCEPT" onMismatch="DENY"/>
       <!-- Flow tracing is most useful with a pattern that shows location.
            Below pattern outputs class, line number and method name. -->
       <PatternLayout pattern="%d{HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n"/>
     </Console>
     <File name="log" fileName="target/test.log" append="false">
       <PatternLayout pattern="%d{HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n"/>
     </File>
   </Appenders>
   <Loggers>
     <Root level="trace">
       <AppenderRef ref="log"/>
     </Root>
   </Loggers>
 </Configuration>
 ----

 Here is the output that results from the Java classes and configuration
 above.

 ....
 19:08:07.056 TRACE com.test.TestService 19 retrieveMessage -  entry
 19:08:07.060 TRACE com.test.TestService 46 getKey -  entry
 19:08:07.060 TRACE com.test.TestService 48 getKey -  exit with (0)
 19:08:07.060 TRACE com.test.TestService 38 getMessage -  entry parms(0)
 19:08:07.060 TRACE com.test.TestService 42 getMessage -  exit with (Hello, World)
 19:08:07.060 TRACE com.test.TestService 23 retrieveMessage -  exit with (Hello, World)
 19:08:07.061 TRACE com.test.TestService 19 retrieveMessage -  entry
 19:08:07.061 TRACE com.test.TestService 46 getKey -  entry
 19:08:07.061 TRACE com.test.TestService 48 getKey -  exit with (1)
 19:08:07.061 TRACE com.test.TestService 38 getMessage -  entry parms(1)
 19:08:07.061 TRACE com.test.TestService 42 getMessage -  exit with (Goodbye Cruel World)
 19:08:07.061 TRACE com.test.TestService 23 retrieveMessage -  exit with (Goodbye Cruel World)
 19:08:07.062 TRACE com.test.TestService 27 exampleException -  entry
 19:08:07.077 DEBUG com.test.TestService 32 exampleException - catching java.lang.ArrayIndexOutOfBoundsException: 3
         at com.test.TestService.exampleException(TestService.java:29) [classes/:?]
         at com.test.App.main(App.java:9) [classes/:?]
         at com.test.AppTest.testApp(AppTest.java:15) [test-classes/:?]
         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_29]
         at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_29]
         at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_29]
         at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_29]
         at org.junit.internal.runners.TestMethodRunner.executeMethodBody(TestMethodRunner.java:99) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestMethodRunner.runUnprotected(TestMethodRunner.java:81) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestMethodRunner.runMethod(TestMethodRunner.java:75) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestMethodRunner.run(TestMethodRunner.java:45) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestClassMethodsRunner.invokeTestMethod(TestClassMethodsRunner.java:66) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestClassMethodsRunner.run(TestClassMethodsRunner.java:35) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestClassRunner$1.runUnprotected(TestClassRunner.java:42) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestClassRunner.run(TestClassRunner.java:52) [junit-4.3.1.jar:?]
         at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:35) [surefire-junit4-2.7.2.jar:2.7.2]
         at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:115) [surefire-junit4-2.7.2.jar:2.7.2]
         at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:97) [surefire-junit4-2.7.2.jar:2.7.2]
         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_29]
         at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_29]
         at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_29]
         at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_29]
         at org.apache.maven.surefire.booter.ProviderFactory$ClassLoaderProxy.invoke(ProviderFactory.java:103) [surefire-booter-2.7.2.jar:2.7.2]
         at $Proxy0.invoke(Unknown Source) [?:?]
         at org.apache.maven.surefire.booter.SurefireStarter.invokeProvider(SurefireStarter.java:150) [surefire-booter-2.7.2.jar:2.7.2]
         at org.apache.maven.surefire.booter.SurefireStarter.runSuitesInProcess(SurefireStarter.java:91) [surefire-booter-2.7.2.jar:2.7.2]
         at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:69) [surefire-booter-2.7.2.jar:2.7.2]
 19:08:07.087 TRACE com.test.TestService 34 exampleException -  exit
 ....

 Simply changing the root logger level to DEBUG in the example above will
 reduce the output considerably.

 ....
 19:13:24.963 DEBUG com.test.TestService 32 exampleException - catching java.lang.ArrayIndexOutOfBoundsException: 3
         at com.test.TestService.exampleException(TestService.java:29) [classes/:?]
         at com.test.App.main(App.java:9) [classes/:?]
         at com.test.AppTest.testApp(AppTest.java:15) [test-classes/:?]
         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_29]
         at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_29]
         at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_29]
         at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_29]
         at org.junit.internal.runners.TestMethodRunner.executeMethodBody(TestMethodRunner.java:99) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestMethodRunner.runUnprotected(TestMethodRunner.java:81) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestMethodRunner.runMethod(TestMethodRunner.java:75) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestMethodRunner.run(TestMethodRunner.java:45) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestClassMethodsRunner.invokeTestMethod(TestClassMethodsRunner.java:66) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestClassMethodsRunner.run(TestClassMethodsRunner.java:35) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestClassRunner$1.runUnprotected(TestClassRunner.java:42) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34) [junit-4.3.1.jar:?]
         at org.junit.internal.runners.TestClassRunner.run(TestClassRunner.java:52) [junit-4.3.1.jar:?]
         at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:35) [surefire-junit4-2.7.2.jar:2.7.2]
         at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:115) [surefire-junit4-2.7.2.jar:2.7.2]
         at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:97) [surefire-junit4-2.7.2.jar:2.7.2]
         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_29]
         at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_29]
         at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_29]
         at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_29]
         at org.apache.maven.surefire.booter.ProviderFactory$ClassLoaderProxy.invoke(ProviderFactory.java:103) [surefire-booter-2.7.2.jar:2.7.2]
         at $Proxy0.invoke(Unknown Source) [?:?]
         at org.apache.maven.surefire.booter.SurefireStarter.invokeProvider(SurefireStarter.java:150) [surefire-booter-2.7.2.jar:2.7.2]
         at org.apache.maven.surefire.booter.SurefireStarter.runSuitesInProcess(SurefireStarter.java:91) [surefire-booter-2.7.2.jar:2.7.2]
         at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:69) [surefire-booter-2.7.2.jar:2.7.2]
 ....
	////
	Licensed to the Apache Software Foundation (ASF) under one or more
	contributor license agreements. See the NOTICE file distributed with
	this work for additional information regarding copyright ownership.
	The ASF licenses this file to You under the Apache License, Version 2.0
	(the "License"); you may not use this file except in compliance with
	the License. You may obtain a copy of the License at

	https://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
	////
	= Log4j 2 API
	Ralph Goers <rgoers@apache.org>

	[#FlowTracing]
	== Flow Tracing

	The `Logger` class provides logging methods that are quite useful for
	following the execution path of applications. These methods generate
	logging events that can be filtered separately from other debug logging.
	Liberal use of these methods is encouraged as the output has been found
	to

	* aid in problem diagnosis in development without requiring a debug
	session
	* aid in problem diagnosis in production where no debugging is possible
	* help educate new developers in learning the application.

	The most used methods are the entry() or traceEntry() and exit() or
	traceExit() methods. entry() or traceEntry() should be placed at the
	beginning of methods, except perhaps for simple getters and setters.
	entry() can be called passing from 0 to 4 parameters. Typically these
	will be parameters passed to the method. traceEntry() can be passed a
	format String and a variable list of parameters, or a Message. The
	entry() and traceEntry() methods log with a level of TRACE and uses a
	Marker with a name of "ENTER" which is also a "FLOW" Marker and all
	message strings will begin with "event", even if a format String or
	Message is used.

	The main difference between the entry and traceEntry methods is that the
	entry method accepts a variable list of objects where presumably each is
	a method parameter. The traceEntry method accepts a format string
	followed by a variable list of objects, presumably included in the
	format String. It is not possible to have a single method that includes
	both of these as it would be ambiguous whether the first String is a
	parameter or a format String.

	An exit() or traceExit() method should be placed before any return
	statement or as the last statement of methods without a return. exit()
	and traceExit() can be called with or without a parameter. Typically,
	methods that return void will use exit() or traceExit() while methods
	that return an Object will use exit(Object obj) or traceExit(object, new
	SomeMessage(object)). The exit() and traceExit() methods log with a
	level of TRACE and uses a Marker with a name of "EXIT" which is also a
	"FLOW" Marker and all message strings will begin with "exit", even if a
	format String or Message is used.

	The throwing() method can be used by an application when it is throwing
	an exception that is unlikely to be handled, such as a RuntimeException.
	This will insure that proper diagnostics are available if needed. The
	logging event generated will have a level of ERROR and will have an
	associated Marker with a name of "THROWING" which is also an "EXCEPTION"
	Marker.

	The catching() method can be used by an application when it catches an
	Exception that it is not going to rethrow, either explicitly or attached
	to another Exception. The logging event generated will have a level of
	ERROR and will have an associated Marker with a name of "CATCHING" which
	is also an "EXCEPTION" Marker.

	The following example shows a simple application using these methods in
	a fairly typical manner. The throwing() is not present since no
	Exceptions are explicitly thrown and not handled.

	[source,java]
	----
	package com.test;

	import org.apache.logging.log4j.Logger;
	import org.apache.logging.log4j.LogManager;

	import java.util.Random;

	public class TestService {
	private Logger logger = LogManager.getLogger(TestService.class.getName());

	private String[] messages = new String[] {
	"Hello, World",
	"Goodbye Cruel World",
	"You had me at hello"
	};
	private Random rand = new Random(1);

	public void setMessages(String[] messages) {
	logger.traceEntry(new JsonMessage(messages));
	this.messages = messages;
	logger.traceExit();
	}

	public String[] getMessages() {
	logger.traceEntry();
	return logger.traceExit(messages, new JsonMessage(messages));
	}

	public String retrieveMessage() {
	logger.entry();

	String testMsg = getMessage(getKey());

	return logger.exit(testMsg);
	}

	public void exampleException() {
	logger.entry();
	try {
	String msg = messages[messages.length];
	logger.error("An exception should have been thrown");
	} catch (Exception ex) {
	logger.catching(ex);
	}
	logger.exit();
	}

	public String getMessage(int key) {
	logger.entry(key);

	String value = messages[key];

	return logger.exit(value);
	}

	private int getKey() {
	logger.entry();
	int key = rand.nextInt(messages.length);
	return logger.exit(key);
	}
	}
	----

	This test application uses the preceding service to generate logging
	events.

	[source,java]
	----
	package com.test;

	public class App {

	public static void main( String[] args ) {
	TestService service = new TestService();
	service.retrieveMessage();
	service.retrieveMessage();
	service.exampleException();
	}
	}
	----

	The configuration below will cause all output to be routed to
	target/test.log. The pattern for the FileAppender includes the class
	name, line number and method name. Including these in the pattern are
	critical for the log to be of value.

	[source,xml]
	----
	<?xml version="1.0" encoding="UTF-8"?>
	<Configuration status="error">
	<Appenders>
	<Console name="Console" target="SYSTEM_OUT">
	<ThresholdFilter level="ERROR" onMatch="ACCEPT" onMismatch="DENY"/>
	<!-- Flow tracing is most useful with a pattern that shows location.
	Below pattern outputs class, line number and method name. -->
	<PatternLayout pattern="%d{HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n"/>
	</Console>
	<File name="log" fileName="target/test.log" append="false">
	<PatternLayout pattern="%d{HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n"/>
	</File>
	</Appenders>
	<Loggers>
	<Root level="trace">
	<AppenderRef ref="log"/>
	</Root>
	</Loggers>
	</Configuration>
	----

	Here is the output that results from the Java classes and configuration
	above.

	....
	19:08:07.056 TRACE com.test.TestService 19 retrieveMessage - entry
	19:08:07.060 TRACE com.test.TestService 46 getKey - entry
	19:08:07.060 TRACE com.test.TestService 48 getKey - exit with (0)
	19:08:07.060 TRACE com.test.TestService 38 getMessage - entry parms(0)
	19:08:07.060 TRACE com.test.TestService 42 getMessage - exit with (Hello, World)
	19:08:07.060 TRACE com.test.TestService 23 retrieveMessage - exit with (Hello, World)
	19:08:07.061 TRACE com.test.TestService 19 retrieveMessage - entry
	19:08:07.061 TRACE com.test.TestService 46 getKey - entry
	19:08:07.061 TRACE com.test.TestService 48 getKey - exit with (1)
	19:08:07.061 TRACE com.test.TestService 38 getMessage - entry parms(1)
	19:08:07.061 TRACE com.test.TestService 42 getMessage - exit with (Goodbye Cruel World)
	19:08:07.061 TRACE com.test.TestService 23 retrieveMessage - exit with (Goodbye Cruel World)
	19:08:07.062 TRACE com.test.TestService 27 exampleException - entry
	19:08:07.077 DEBUG com.test.TestService 32 exampleException - catching java.lang.ArrayIndexOutOfBoundsException: 3
	at com.test.TestService.exampleException(TestService.java:29) [classes/:?]
	at com.test.App.main(App.java:9) [classes/:?]
	at com.test.AppTest.testApp(AppTest.java:15) [test-classes/:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_29]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_29]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_29]
	at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_29]
	at org.junit.internal.runners.TestMethodRunner.executeMethodBody(TestMethodRunner.java:99) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestMethodRunner.runUnprotected(TestMethodRunner.java:81) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestMethodRunner.runMethod(TestMethodRunner.java:75) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestMethodRunner.run(TestMethodRunner.java:45) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestClassMethodsRunner.invokeTestMethod(TestClassMethodsRunner.java:66) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestClassMethodsRunner.run(TestClassMethodsRunner.java:35) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestClassRunner$1.runUnprotected(TestClassRunner.java:42) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestClassRunner.run(TestClassRunner.java:52) [junit-4.3.1.jar:?]
	at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:35) [surefire-junit4-2.7.2.jar:2.7.2]
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:115) [surefire-junit4-2.7.2.jar:2.7.2]
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:97) [surefire-junit4-2.7.2.jar:2.7.2]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_29]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_29]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_29]
	at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_29]
	at org.apache.maven.surefire.booter.ProviderFactory$ClassLoaderProxy.invoke(ProviderFactory.java:103) [surefire-booter-2.7.2.jar:2.7.2]
	at $Proxy0.invoke(Unknown Source) [?:?]
	at org.apache.maven.surefire.booter.SurefireStarter.invokeProvider(SurefireStarter.java:150) [surefire-booter-2.7.2.jar:2.7.2]
	at org.apache.maven.surefire.booter.SurefireStarter.runSuitesInProcess(SurefireStarter.java:91) [surefire-booter-2.7.2.jar:2.7.2]
	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:69) [surefire-booter-2.7.2.jar:2.7.2]
	19:08:07.087 TRACE com.test.TestService 34 exampleException - exit
	....

	Simply changing the root logger level to DEBUG in the example above will
	reduce the output considerably.

	....
	19:13:24.963 DEBUG com.test.TestService 32 exampleException - catching java.lang.ArrayIndexOutOfBoundsException: 3
	at com.test.TestService.exampleException(TestService.java:29) [classes/:?]
	at com.test.App.main(App.java:9) [classes/:?]
	at com.test.AppTest.testApp(AppTest.java:15) [test-classes/:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_29]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_29]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_29]
	at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_29]
	at org.junit.internal.runners.TestMethodRunner.executeMethodBody(TestMethodRunner.java:99) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestMethodRunner.runUnprotected(TestMethodRunner.java:81) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestMethodRunner.runMethod(TestMethodRunner.java:75) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestMethodRunner.run(TestMethodRunner.java:45) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestClassMethodsRunner.invokeTestMethod(TestClassMethodsRunner.java:66) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestClassMethodsRunner.run(TestClassMethodsRunner.java:35) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestClassRunner$1.runUnprotected(TestClassRunner.java:42) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34) [junit-4.3.1.jar:?]
	at org.junit.internal.runners.TestClassRunner.run(TestClassRunner.java:52) [junit-4.3.1.jar:?]
	at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:35) [surefire-junit4-2.7.2.jar:2.7.2]
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:115) [surefire-junit4-2.7.2.jar:2.7.2]
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:97) [surefire-junit4-2.7.2.jar:2.7.2]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_29]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_29]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_29]
	at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_29]
	at org.apache.maven.surefire.booter.ProviderFactory$ClassLoaderProxy.invoke(ProviderFactory.java:103) [surefire-booter-2.7.2.jar:2.7.2]
	at $Proxy0.invoke(Unknown Source) [?:?]
	at org.apache.maven.surefire.booter.SurefireStarter.invokeProvider(SurefireStarter.java:150) [surefire-booter-2.7.2.jar:2.7.2]
	at org.apache.maven.surefire.booter.SurefireStarter.runSuitesInProcess(SurefireStarter.java:91) [surefire-booter-2.7.2.jar:2.7.2]
	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:69) [surefire-booter-2.7.2.jar:2.7.2]
	....