使用osgi内嵌jetty作为web服务器进行web开发时，遇到错误：
org.apache.commons.logging.logconfigurationexception:no suitable log constructor [Ljava.lang.class;@1ccf0ad for org.apache.commons.logging.impl.log4jlogger(caused by java.lang.noclassdeffounderror:org/apache/log4j/category)]org.apach
