java核心技术这本书怎么样?另外,我刚遇上一个问题,就是在JCreator里碰上这些东西
java.lang.NoClassDefFoundError: youyici
Caused by: java.lang.ClassNotFoundException: youyici
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
Could not find the main class: youyici. Program will exit.
Exception in thread "main"
Process completed.
怎么对付啊?望指教