我有以下文件夹结构。。。
MyApp
|com
|lib
|--- log4j-1.2.17.jar,mysqlconn.jar,jcalendar-1.4.jar,poi-3.9.jar
|prop
|---log4j.properties
|manifest.txt
manifest.txt:
Main-Class: com.java.test.WelcomeScreen
Class-Path: prop lib/jcalendar-1.4.jar lib/log4j-1.2.17.jar lib/mysql-connector-java-5.0.8-bin.jar lib/poi-3.9.jar
我正在创建如下可执行jar:
C:UsersAdministratorDesktopMyApp>jar -cvfm myapp.jar manifest.txt com/java/test/*.class com/java/db/*.class
然后运行:
C:UsersAdministratorDesktopMyApp>java -jar myapp.jar
我得到以下错误:
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/log4j/Logger
at com.java.test.LoginForm.<clinit>(LoginForm.java:17)
at com.java.test.WelcomeScreen.main(WelcomeScreen.java:134)
Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Logger
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 2 more
您需要在清单的末尾添加一个空行。此外,仅包括目录也可以用于log4j.properties
所在的位置。我建议将log4.properties放在与主jar文件相同的路径中,并在类路径中添加"."。但是,在目录末尾添加一个/
看起来就像OP所发现的那样。