Update README.md

Added logging details

java/README.md

@@ -40,6 +40,73 @@ $ ant test
 $ ant clean build test
 ```
 
+###Configuring Logging
+Pubnub implements swappable logging using SLF4J, which allows you to switch different logging frameworks easily. All the logging calls using SLF4J API will be delegated to the underlying logging framework.
+
+Before you enable logging, you need to create a "debug-build" version of the Pubnub-StandardEdition.jar.
+
+####To create a debug-build
+
+1. Go to Terminal on Mac/Linux or command-line on Windows
+2. Change directory to the Java folder where you have cloned the git java repo of pubnub (https://github.com/pubnub/java.git)
+3. Type "ant debug-build"
+4. The debug version of Pubnub-StandardEdition jar file (e.g Pubnub-StandardEdition-3.x.x.jar) will be created.
+5. Add this jar as a reference in your project.
+
+To implement logging using log4j you need to add the following references to the project. Using log4j you can log to console or a file or both.
+
+1. slf4j-api jar file (e.g. slf4j-api-1.7.5.jar or a latest version) which is the SLF4J API
+2. slf4j-log4j jar file (e.g. slf4j-log4j-1.7.5.jar or a latest version) which acts as a bridge between slf4j and log4j
+3. log4j jar file (log4j-1.2.17.jar or a latest version), which provides the underlying logging framework
+4. Along with these references you need to add the log4j.properties file in the CLASSPATH
+
+For example, in your log4j.properties file, configure it to write the logs to a log file:
+```java
+# Root logger option
+log4j.rootLogger=ALL, FILE
+
+# Direct log messages to a log file
+log4j.appender.FILE =org.apache.log4j.FileAppender
+log4j.appender.FILE.File=/Users/rajat/Projects/eclipsews/log4jloging.log
+log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
+log4j.appender.FILE.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
+```
+
+More info can be found here http://www.tutorialspoint.com/log4j/log4j_configuration.htm
+
+
+ii) To implement logging using simple slf4j you need to add the following references to the project
+- slf4j-api jar file (e.g. slf4j-api-1.7.5.jar or a latest version) which is the SLF4J API
+- slf4j-simple jar file (e.g. slf4j-simple-1.7.5.jar or a latest version) which provides the underlying logging framework
+- Along with these references you need to add the simplelogger.properties file in the CLASSPATH
+
+iii) To implement logging using logback-classic you need to add the following references to the project
+- slf4j-api jar file (e.g. slf4j-api-1.7.5.jar or a latest version) which is the SLF4J API
+- logback-classic and logback-core jar files which provide the underlying logging framework
+
+iv) To implement logging using java.util.logging you need to add the following references to the project
+- slf4j-api jar file (e.g. slf4j-api-1.7.5.jar or a latest version) which is the SLF4J API
+- slf4j-jdk14 jar file which acts as a bridge between slf4j and java
+- JVM runtime provides the underlying logging framework
+
+v) To implement logging using commons-logging you need to add the following references to the project
+- slf4j-api jar file (e.g. slf4j-api-1.7.5.jar or a latest version) which is the SLF4J API
+- slf4j-jcl jar file which acts as a bridge between slf4j and common-logging
+- common-logging.jar file which acts as an abstraction layer
+- The underlying logging framework is chosen dynamically by commons-logging
+
+vi) To implement no logging you have two options
+
+Option 1:
+- Add the reference of slf4j-api jar file (e.g. slf4j-api-1.7.5.jar or a latest version) which is the SLF4J API and nothing else.
+
+Option 2:
+- Add the reference of slf4j-api jar file (e.g. slf4j-api-1.7.5.jar or a latest version) which is the SLF4J API.
+- And add a reference to slf4j-nop jar file (e.g. slf4j-nop-1.7.5.jar or a latest version).
+
+
+More info on SLF4J can be found at http://stackoverflow.com/questions/8737204/how-slf4j-works-no-log-getting-created
+
 ###To run the DemoConsole:
 ```
 $ cd jars