commons-logging-1.0.4.jar 使用

Configuring the Commons Logging Package

Choosing a LogFactory Implementation

From an application perspective, the first requirement is to retrieve an object reference to the LogFactory instance that will be used to create Log instances for this application. This is normally accomplished by calling the static getFactory() method. This method implements the following discovery algorithm to select the name of the LogFactory implementation class this application wants to use:

• Check for a system property named org.apache.commons.logging.LogFactory.
• Use the JDK 1.3 JAR Services Discovery mechanism (see http://java.sun.com/j2se/1.3/docs/guide/jar/jar.html for more information) to look for a resource named META-INF/services/org.apache.commons.logging.LogFactory whose first line is assumed to contain the desired class name.
• Look for a properties file named commons-logging.properties visible in the application class path, with a property named org.apache.commons.logging.LogFactory defining the desired implementation class name.
• Fall back to a default implementation, which is described further below.

If a commons-logging.properties file is found, all of the properties defined there are also used to set configuration attributes on the instantiated LogFactory instance.

使用必须:
commons-logging-1.0.4.jar
log4j-1.2.9.jar
log4j.properties