How do I get log4J to work - I'm getting "package org.apache.log4j does not exist"

Question

i know this may be a newbie qestion, but I'm having issues with setting up Log4J: I want to run a log4j demo, and here's my code: ``` import org.apache.log4j.Logger; import org.apache.log4j.BasicConfigurator; public class HelloLOG4j { private static final Logger logger = Logger.getLogger(Hello.class); public static void main(String argv[]) { BasicConfigurator.configure(); logger.debug("Hello world."); logger.info("What a beatiful day."); } } ``` I set my Classpath: C:\Users\Adel\Downloads\apache-log4j-1.2.17\log4j-1.2.17.jar in both System and User var's But when I run my program I still get ``` errors found: File: C:\Users\Adel\Desktop\various_topics\JavaProjects\HelloLOG4j.java [line: 2] Error: package org.apache.log4j does not exist ``` I know that I set classpath right - if I run cmd line: ``` C:\Program Files\Java\jdk1.6.0_20>print %LOG4J_HOME% C:\Users\Adel\Downloads\apache-log4j-1.2.17\log4j-1.2.17.jar is currently bein g printed ```

Accepted Answer

You need to add log4j home to the classpath as the JVM needs the path to the log4j classes

if on windows, you can use

```
set classpath=%classpath%;%LOG4J_HOME%
```

On linux/ ubuntu (much better than windows for development & servers)

```
export classpath=$classpath:$LOG4J_HOME
```

then run your app after adding other paths to classpath like

```
set classpath=%classpath%;c:\users\adel\....
```

You do not need to add log4JHOME again - as `%classpath%;` will add to the current classpath.

LOG4J_HOME is not known to Java. It is just used by log4j in case of auto config/default config.

On a side note try using the new log4j2 !

How do I get log4J to work - I'm getting "package org.apache.log4j does not exist"

Solution

Problem