cyber-logging

Crafted with ♥ in Cybercom Poland

Cyber-logging is tool to log Java method input and output just by single annotation.

Although using annotation for logging is typical, cyber-logging simplifies effort get full-feature log content.

Simple example:

@Logged
public int add(int a, @NotLogged int b) {
    return a + b;
}

Logged information:

• Entering MyBean.add with [2,2]
• Exiting MyBean.add with 4

cyber-logging benefits

1. By default objects are logged in JSON format. This is best profit, because full object content is visible in log without any additional effort.
2. Way how objects are written to log can be customized (save object as JSON, use toString() or own implementation)
3. @NotLogged excludes from logging fragile, heavy, trivial or just unwanted methods and/or parameters
4. Possible enhance logs with extra information, for example session id, username, to help tracking concrete flow
5. Uniform usage for POJO, Spring and EJB (as much as possible)

POJO usage - JDK proxy

Manually build proxy over target object to catch method calls and trigger logging. Example:

MyBean target = new MyBean();
IMyBean proxy = LoggedProxy.createProxy(target, IMyBean.class);
proxy.foo();

LoggedProxy applies default logging policy. For custom policy, use own implementation.

In order to use cyber-logging with pojo object the object must implement interface with methods for logging. This requirement may be burdensome.

Join logging to your application

<dependency>
  <groupId>com.cybercom.logging</groupId>
  <artifactId>logging-core</artifactId>
  <version>0.0.2</version>
</dependency>

POJO usage - cglib

Manually build proxy over target object to catch method calls and trigger logging. Example:

MyBean target = new MyBean();
MyBean proxy = LoggedCglibProxy.createProxy(target);
proxy.foo();

LoggedCglibProxy applies default logging policy. For custom policy, use own implementation.

Classes don't have to have interface to be proxied by cglib

Join logging to your application

<dependency>
  <groupId>com.cybercom.logging</groupId>
  <artifactId>logging-cglib</artifactId>
  <version>0.0.2</version>
</dependency>    

EJB usage

Annotate EJB on class or method level with annotaton com.cybercom.logging.ejb.Logged.

@Logged
public class MyBean...

For custom logging policy, use own annotation and interceptor. Example

Join logging to your application

<dependency>
  <groupId>com.cybercom.logging</groupId>
  <artifactId>logging-ejb</artifactId>
  <version>0.0.2</version>
</dependency>	

Spring usage

1. Activate aspects in you application
2. Define and configure bean com.cybercom.logging.spring.LoggedSpringAspect
3. Annotate Spring bean on class or method level with annotation com.cybercom.logging.spring.Logged.

@Logged
public class MyBean...

Example

For custom logging policy, Spring not need custom implementation, because policy can be configured in Spring descriptor

Minimal Spring configuration

Add to your pom dependency

<dependency>
  <groupId>com.cybercom.logging</groupId>
  <artifactId>logging-spring</artifactId>
  <version>0.0.2</version>
</dependency>	

Configure the bean

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
 http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
<aop:aspectj-autoproxy proxy-target-class="true" />
<bean class="com.cybercom.logging.spring.LoggedSpringAspect"/>

Log level configuration

Cyber-logging use slf4j facade for logging. Level is debug. To see logged data configure com.cybercom.logging.core.EntryExitMethodLogger on level DEBUG

Troubleshooting

Nothing is logged

Add to the following line to your code:

org.slf4j.LoggerFactory.getLogger("com.cybercom.logging.core.EntryExitMethodLogger").debug("Check logging");

If you see message Check logging in your logs then log configuration is OK and problem is somewhere else. Otherwise fix log configuration

I have error "error the @within pointcut expression is only supported at Java 5 compliance level or above"

see http://stackoverflow.com/questions/15678417/error-when-using-aspectj-aop-with-java-7

Configuration

See Javadoc for EntryExitMethodLogger

Examples

See demo

Development notes

In order to have cyber-logging in one Maven artifact, each artifact contains all required classes. (Simply, logging-ejb contains all classes from logging-core). To achieve the goal, child modules (logging-ejb, logging-spring) include source folder of logging-core. But it is not handled by Eclipse plugin for Maven.

To work with cyber-logging with Eclipse I import all projects and add dependency to logging-core manually