Java – ERROR Could not instantiate class [org.apache.log4j.rolling.RollingFileAppender]

javalog4j

I am using log4j-1.2.17.jar and apache-log4j-extras-1.2.17.jar.

I want to enable rolling files but when i try to startup server y recibed errors..

My log4j.properties file looks like this.

log4j.appender.LOG_CRON_SIJ=org.apache.log4j.rolling.RollingFileAppender
log4j.appender.LOG_CRON_SIJ.append=true
log4j.appender.LOG_CRON_SIJ.encoding=UTF-8
log4j.appender.LOG_CRON_SIJ.rollingPolicy=org.apache.log4j.rolling.TimeBasedRollingPolicy
log4j.appender.LOG_CRON_SIJ.rollingPolicy.FileNamePattern=${rootLog}/agendaNojCRONSIJ_%d{dd-MM-yyyy HH-mm-ss}.log
log4j.appender.LOG_CRON_SIJ.rollingPolicy.activeFileName=${rootLog}/agendaNojCRONSIJ.log
log4j.appender.LOG_CRON_SIJ.triggeringPolicy=org.apache.log4j.rolling.SizeBasedTriggeringPolicy
log4j.appender.LOG_CRON_SIJ.triggeringPolicy.maxFileSize=52428800
log4j.appender.LOG_CRON_SIJ.layout=org.apache.log4j.EnhancedPatternLayout
log4j.appender.LOG_CRON_SIJ.layout.ConversionPattern=%d %-5p %c - %m%n

errors:

   log4j:ERROR Could not instantiate class [org.apache.log4j.rolling.RollingFileAppender].
java.lang.ClassNotFoundException: org.apache.log4j.rolling.RollingFileAppender
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:171)
    at org.apache.log4j.helpers.Loader.loadClass(Loader.java:198)
    at org.apache.log4j.helpers.OptionConverter.instantiateByClassName(OptionConverter.java:327)
    at org.apache.log4j.helpers.OptionConverter.instantiateByKey(OptionConverter.java:124)
    at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:785)
    ...
    ...
    ...
log4j:ERROR Could not instantiate appender named "LOG_CRON_SIJ".
log4j:ERROR Could not instantiate class [org.apache.log4j.rolling.RollingFileAppender].
java.lang.ClassNotFoundException: org.apache.log4j.rolling.RollingFileAppender
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:171)
    at org.apache.log4j.helpers.Loader.loadClass(Loader.java:198)
    at org.apache.log4j.helpers.OptionConverter.instantiateByClassName(OptionConverter.java:327)
    at org.apache.log4j.helpers.OptionConverter.instantiateByKey(OptionConverter.java:124)
    ....
    ....

log4j:WARN Failed to set property [triggeringPolicy] to value "org.apache.log4j.rolling.SizeBasedTriggeringPolicy". 
log4j:WARN Failed to set property [rollingPolicy] to value "org.apache.log4j.rolling.TimeBasedRollingPolicy". 
log4j:WARN Please set a rolling policy for the RollingFileAppender named 'LOG_CRON_SIJ'

Can anybody help me???

Best Answer

Please check if you have required dependencies for RollingFileAppender (Apache Log4j 1.2.17 API) in your classpath. If any class is not found in your classpath that is actually instantiating somewhere you will encounter such error. So please check the logging dependency.

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Java – How to test a class that has private methods, fields or inner classes

Update:

Some 10 years later perhaps the best way to test a private method, or any inaccessible member, is via @Jailbreak from the Manifold framework.
@Jailbreak Foo foo = new Foo();
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This way your code remains type-safe and readable. No design compromises, no overexposing methods and fields for the sake of tests.

If you have somewhat of a legacy Java application, and you're not allowed to change the visibility of your methods, the best way to test private methods is to use reflection.

Internally we're using helpers to get/set private and private static variables as well as invoke private and private static methods. The following patterns will let you do pretty much anything related to the private methods and fields. Of course, you can't change private static final variables through reflection.

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And for fields:

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From the Java Tutorial:

Nested classes are divided into two categories: static and non-static. Nested classes that are declared static are simply called static nested classes. Non-static nested classes are called inner classes.

Static nested classes are accessed using the enclosing class name:

OuterClass.StaticNestedClass

For example, to create an object for the static nested class, use this syntax:

OuterClass.StaticNestedClass nestedObject = new OuterClass.StaticNestedClass();

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see: Java Tutorial - Nested Classes

For completeness note that there is also such a thing as an inner class without an enclosing instance:

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Best Answer

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