log4j:ERROR Failed to load driver java.lang.ClassNotFoundException: com.mysql.jdbc.Driver at java.net.URLClassLoader.findClass(URLClassLoader.java:381) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:264) at org.apache.log4j.jdbc.JDBCAppender.setDriver(JDBCAppender.java:391) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.log4j.config.PropertySetter.setProperty(PropertySetter.java:245) at org.apache.log4j.config.PropertySetter.setProperty(PropertySetter.java:204) at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:169) at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:104) at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:842) at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:768) at org.apache.log4j.PropertyConfigurator.configureRootCategory(PropertyConfigurator.java:648) at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:514) at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:580) at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:526) at org.apache.log4j.LogManager.<clinit>(LogManager.java:127) at org.apache.log4j.Logger.getLogger(Logger.java:117) at top.simba1949.AppTest.<clinit>(AppTest.java:11)
解决方案：
将log4j.properties 中每行后面的空格都删除就解决了.
