Java: find jar

When you are looking for a given Java class, you can use this online database to locate jars:

Example, looking for log4j

http://www.findjar.com/index.x?query=log4j

Among others I get response:

[JAR] log4j-1.1.3.jar in log4j/log4j/1.1.3
[JAR] log4j-1.2.11.jar in log4j/log4j/1.2.11
[JAR] log4j-1.2.12.jar in log4j/log4j/1.2.12