My application logging crashes during maven build in the tests. This is the log4j2.xml what I have in the src/test/resources:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="INFO">
<Appenders>
<Console name="stdout" target="SYSTEM_OUT">
<PatternLayout pattern="MyApp: %d{yyyy-MM-dd HH:mm:ss,SSS} %5p [%t] %c{1.} - %m%n" />
</Console>
</Appenders>
<Loggers>
<Logger name="com.my.app" level="info" additivity="false">
<Appender-ref ref="stdout"/>
</Logger>
<Root level="error">
<Appender-ref ref="stdout"/>
</Root>
</Loggers>
</Configuration>
And I get this exception during test during build:
2017-11-23 15:12:28,371 main ERROR An exception occurred processing Appender stdout java.lang.NullPointerException
at org.apache.logging.log4j.core.impl.ThrowableProxy.toExtendedStackTrace(ThrowableProxy.java:671)
at org.apache.logging.log4j.core.impl.ThrowableProxy.<init>(ThrowableProxy.java:138)
at org.apache.logging.log4j.core.impl.ThrowableProxy.<init>(ThrowableProxy.java:122)
at org.apache.logging.log4j.core.impl.Log4jLogEvent.getThrownProxy(Log4jLogEvent.java:566)
at org.apache.logging.log4j.core.pattern.ExtendedThrowablePatternConverter.format(ExtendedThrowablePatternConverter.java:64)
at org.apache.logging.log4j.core.pattern.PatternFormatter.format(PatternFormatter.java:38)
at org.apache.logging.log4j.core.layout.PatternLayout$PatternSerializer.toSerializable(PatternLayout.java:333)
at org.apache.logging.log4j.core.layout.PatternLayout.toText(PatternLayout.java:232)
at org.apache.logging.log4j.core.layout.PatternLayout.encode(PatternLayout.java:217)
at org.apache.logging.log4j.core.layout.PatternLayout.encode(PatternLayout.java:57)
at org.apache.logging.log4j.core.appender.AbstractOutputStreamAppender.directEncodeEvent(AbstractOutputStreamAppender.java:177)
at org.apache.logging.log4j.core.appender.AbstractOutputStreamAppender.tryAppend(AbstractOutputStreamAppender.java:170)
at org.apache.logging.log4j.core.appender.AbstractOutputStreamAppender.append(AbstractOutputStreamAppender.java:161)
at org.apache.logging.log4j.core.config.AppenderControl.tryCallAppender(AppenderControl.java:156)
at org.apache.logging.log4j.core.config.AppenderControl.callAppender0(AppenderControl.java:129)
at org.apache.logging.log4j.core.config.AppenderControl.callAppenderPreventRecursion(AppenderControl.java:120)
at org.apache.logging.log4j.core.config.AppenderControl.callAppender(AppenderControl.java:84)
at org.apache.logging.log4j.core.config.LoggerConfig.callAppenders(LoggerConfig.java:448)
at org.apache.logging.log4j.core.config.LoggerConfig.processLogEvent(LoggerConfig.java:433)
at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:417)
at org.apache.logging.log4j.core.config.LoggerConfig.logParent(LoggerConfig.java:439)
at org.apache.logging.log4j.core.config.LoggerConfig.processLogEvent(LoggerConfig.java:434)
at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:417)
at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:403)
at org.apache.logging.log4j.core.config.AwaitCompletionReliabilityStrategy.log(AwaitCompletionReliabilityStrategy.java:63)
at org.apache.logging.log4j.core.Logger.logMessage(Logger.java:146)
at org.apache.logging.log4j.spi.AbstractLogger.tryLogMessage(AbstractLogger.java:2116)
at org.apache.logging.log4j.spi.AbstractLogger.logMessageSafely(AbstractLogger.java:2100)
at org.apache.logging.log4j.spi.AbstractLogger.logMessage(AbstractLogger.java:1994)
at org.apache.logging.log4j.spi.AbstractLogger.logIfEnabled(AbstractLogger.java:1966)
at org.apache.logging.slf4j.Log4jLogger.error(Log4jLogger.java:319)
at com.my.app.MyTest.testingMyApp(MyTest.java:89)
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:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.ExpectException.evaluate(ExpectException.java:19)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl.run(JUnit45AndHigherRunnerImpl.java:37)
at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:62)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:283)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:173)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:128)
at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:203)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:155)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103)
This is my pom:
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-web</artifactId>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-jul</artifactId>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-jcl</artifactId>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
</dependency>
<dependency>
<groupId>org.dblock.log4jna</groupId>
<artifactId>log4jna-api</artifactId>
</dependency>
The version of log4j is 2.9.1
And the funny thing, that it logs to the console, for example when the spring application starting, then there I can see the logs which are coming from the MyApplication.java which has the @SpringBootApplication annotation.
And MyTest.java:89 is:
logger.error("error occured",e);
And the logger is coming from:
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
So it looks like it crashes during error log, but there is no problem if I log a normal info.
So what is this nullpointer?
Ok, I figured it out: it is because in the test class I have a mock exception. If I change it to creating a new object from the exception, it works fine.
It is a good candidate for reporting a bug I guess.