com.blazegraph.gremlin.util

Class LambdaLogger

java.lang.Object

org.apache.log4j.Category

org.apache.log4j.Logger

com.blazegraph.gremlin.util.LambdaLogger

All Implemented Interfaces:

org.apache.log4j.spi.AppenderAttachable

public class LambdaLogger
extends org.apache.log4j.Logger

Wrap conditional logging using Java 8 lambdas. To use this functionality, simply request a LambdaLogger instead of a normal Logger: LambdaLogger log = LambdaLogger.getLogger(Foo.class) To log conditionally, simply use this syntax: log.debug(() -> getMessage()); // getMessage() only called if log level >= DEBUG In this example getMessage() will not be called unless the log level is set to DEBUG or higher. Conditional logging drastically improves performance and should ALWAYS be preferred in production (non-test) code over the unconditional logging syntax: log.debug(getMessage()); // getMessage() called regardless of log level

Author:

mikepersonick

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	LambdaLogger.Supplier<T> Checked exception throwing version of Supplier<T>.

Field Summary

Fields inherited from class org.apache.log4j.Category

additive, level, name, parent, repository, resourceBundle

Method Summary

Modifier and Type	Method and Description
void	debug(LambdaLogger.Supplier<Object> supplier) Conditionally log at DEBUG.
static LambdaLogger	getLogger(Class c) Override to return a LambdaLogger.
static LambdaLogger	getLogger(String name) Override to return a LambdaLogger.
void	info(LambdaLogger.Supplier<Object> supplier) Conditionally log at INFO.
protected void	log(org.apache.log4j.Level level, LambdaLogger.Supplier<Object> supplier) Conditionally log at the specified level.
static void	quiet(Class<?> cls, Code code) Run the supplied code, quieting the supplied log at Level.ERROR
static void	quiet(Class<?> cls, org.apache.log4j.Level set, Code code) Run the supplied code, quieting the supplied log with the specified Level
void	trace(LambdaLogger.Supplier<Object> supplier) Conditionally log at TRACE.

Methods inherited from class org.apache.log4j.Logger

getLogger, getRootLogger, isTraceEnabled, trace, trace

Methods inherited from class org.apache.log4j.Category

addAppender, assertLog, callAppenders, debug, debug, error, error, exists, fatal, fatal, forcedLog, getAdditivity, getAllAppenders, getAppender, getChainedPriority, getCurrentCategories, getDefaultHierarchy, getEffectiveLevel, getHierarchy, getInstance, getInstance, getLevel, getLoggerRepository, getName, getParent, getPriority, getResourceBundle, getResourceBundleString, getRoot, info, info, isAttached, isDebugEnabled, isEnabledFor, isInfoEnabled, l7dlog, l7dlog, log, log, log, removeAllAppenders, removeAppender, removeAppender, setAdditivity, setLevel, setPriority, setResourceBundle, shutdown, warn, warn

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

quiet

public static final void quiet(Class<?> cls,
                               Code code)
                        throws Exception

Run the supplied code, quieting the supplied log at Level.ERROR

Throws:

Exception

quiet

public static final void quiet(Class<?> cls,
                               org.apache.log4j.Level set,
                               Code code)
                        throws Exception

Run the supplied code, quieting the supplied log with the specified Level

Throws:

Exception

getLogger

public static LambdaLogger getLogger(String name)

Override to return a LambdaLogger.

getLogger

public static LambdaLogger getLogger(Class c)

Override to return a LambdaLogger.

log

protected void log(org.apache.log4j.Level level,
                   LambdaLogger.Supplier<Object> supplier)

Conditionally log at the specified level. Does not call supplier.get() unless log.getLevel() >= level (conditional message production). If the supplied object is a stream, conditionally log each object in the stream on a separate line.

info

public void info(LambdaLogger.Supplier<Object> supplier)

Conditionally log at INFO. Does not call supplier.get() unless log.isInfoEnabled() == true (conditional message production). If the supplied object is a stream, conditionally log each object in the stream on a separate line.

debug

public void debug(LambdaLogger.Supplier<Object> supplier)

Conditionally log at DEBUG. Does not call supplier.get() unless log.isDebugEnabled() == true (conditional message production). If the supplied object is a stream, conditionally log each object in the stream on a separate line.

trace

public void trace(LambdaLogger.Supplier<Object> supplier)

Conditionally log at TRACE. Does not call supplier.get() unless log.isTraceEnabled() == true (conditional message production). If the supplied object is a stream, conditionally log each object in the stream on a separate line.