应该是就是文件名和类名的问题。 如果书上是 public class Helloworld{} 就把文件名命名为Helloworld.java再试试 ？
同意楼上的说法,java.lang.NoClassDefFoundError 就是这个错误.
public class NoClassDefFoundError extends LinkageErrorThrown if the Java Virtual Machine or a classloader tries to load in the definition of a class (as part of a normal method call or as part of creating a new instance using the new expression) and no definition of the class could be found. The searched-for class definition existed when the currently executing class was compiled, but the definition can no longer be found.
如果书上是
public class Helloworld{}
就把文件名命名为Helloworld.java再试试 ？
extends LinkageErrorThrown if the Java Virtual Machine or a classloader tries to load in the definition of a class (as part of a normal method call or as part of creating a new instance using the new expression) and no definition of the class could be found. The searched-for class definition existed when the currently executing class was compiled, but the definition can no longer be found.