日志适配扩展

-Ddubbo:application.logger=xxx

• org.apache.dubbo.common.logger.jcl.JclLoggerAdapter
• org.apache.dubbo.common.logger.log4j.Log4jLoggerAdapter
• org.apache.dubbo.common.logger.jdk.JdkLoggerAdapter

Maven 项目结构：

package com.xxx;
public class XxxLoggerAdapter implements LoggerAdapter {
    public Logger getLogger(URL url) {
        // ...
    }

XxxLogger.java：