commonslogfactorybean.java

spring api 源代码

/*
 * Copyright 2002-2005 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.beans.factory.config;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;

/**
 * Factory bean for
 * <a href="http://jakarta.apache.org/commons/logging.html">commons-logging</a>
 * {@link org.apache.commons.logging.Log} instances.
 *
 * <p>Useful for sharing Log instances among multiple beans instead of using
 * one Log instance per class name, e.g. for common log topics.
 *
 * @author Juergen Hoeller
 * @see org.apache.commons.logging.Log
 * @since 16.11.2003
 */
public class CommonsLogFactoryBean implements FactoryBean, InitializingBean {

    private Log log;


    /**
     * The name of the log.
     * <p>This property is required.
     * @param logName the name of the log
     */
    public void setLogName(String logName) {
        this.log = LogFactory.getLog(logName);
    }


    public void afterPropertiesSet() {
        if (this.log == null) {
            throw new IllegalArgumentException("logName is required");
        }
    }

    public Object getObject() {
        return log;
    }

    public Class getObjectType() {
        return (this.log != null ? this.log.getClass() : Log.class);
    }

    public boolean isSingleton() {
        return true;
    }

}