Question

我不知道为什么会出现运行时错误，我已经搜索了问题，并且说在编译期间可用的类在运行时不再可用。

这是代码：

package examples.RMIShape;
import java.rmi.*;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
//import java.rmi.server.UnicastRemoteObject;

public class ShapeListServer {
    public static void main(String args[]){
//      System.setSecurityManager(new RMISecurityManager());
        System.out.println("Main OK");
        try{
            ShapeList aShapelist = new ShapeListServant();
            System.out.println("After create");
            String registryURL = "rmi://localhost:" + "/ShapeList";
            startRegistry();
            Naming.rebind(registryURL, aShapelist);
            System.out.println("ShapeList server ready");
        }catch(Exception e) {
            System.out.println("ShapeList server main " + e.getMessage());
        }
    }

    // This method starts a RMI registry on the local host, if it
    // does not already exists at the specified port number.
    private static void startRegistry()throws RemoteException{
        Registry registry;
        try {
            registry = LocateRegistry.getRegistry();
            registry.list( );  // This call will throw an exception
            // if the registry does not already exist
        }
        catch (RemoteException e) {
            // No valid registry at that port.
            System.out.println ("RMI registry cannot be located at port " + Registry.REGISTRY_PORT );
            registry = LocateRegistry.createRegistry(Registry.REGISTRY_PORT);
            System.out.println("RMI registry created at port " + Registry.REGISTRY_PORT);
        }
    } // end startRegistry
}

Answer 1

我已经搜索了问题，并且说在编译期间可用的类在运行时不再可用。

这不正确。这会导致ClassNotFoundException。这个有几个原因，但最常见的是文件中的类不是文件名和目录层次结构隐含的类。

Answer 2

如果Java虚拟机或ClassLoader实例尝试加载类的定义（作为普通方法调用的一部分或作为使用新表达式创建新实例的一部分），则抛出Basicall java.lang.NoClassDefFoundError没有找到班级的定义。

以下链接将有所帮助。此链接将指导您解决问题。

http://javarevisited.blogspot.in/2011/06/noclassdeffounderror-exception-in.html

http://javaeesupportpatterns.blogspot.in/2012/06/javalangnoclassdeffounderror-how-to.html

希望这会有所帮助

java.lang.NoClassDefFoundError

2 个答案: