C:\myjava>java a
Exception in thread "main" java.lang.NoClassDefFoundError: a (wrong name: A)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:12
3)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302
这个错误是不是我JAVA的环境没有配置好还是怎么回事??
运行的代码是这个:
class A{
public A() {
System.out.println("A");
}
}
class B extends A{
public B(){
System.out.println("B");
}
public static void main(String[] args){
B b=new B();
}
}
Exception in thread "main" java.lang.NoClassDefFoundError: a (wrong name: A)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:12
3)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302
这个错误是不是我JAVA的环境没有配置好还是怎么回事??
运行的代码是这个:
class A{
public A() {
System.out.println("A");
}
}
class B extends A{
public B(){
System.out.println("B");
}
public static void main(String[] args){
B b=new B();
}
}
C:\myjava>java A
Exception in thread "main" java.lang.NoSuchMethodError: main
我现在用的代码是:
class lesson22
{
public static viod main(string[] args)
{
int x=6;
if (x<3)
{ system.out.println("x<3");
system.out.println("ok");
}
else
system.out.println("x>+3");
}
}
运行时候出来的就是这个错误了:
C:\myjava>java lesson22.java
Exception in thread "main" java.lang.NoClassDefFoundError: lesson22/java
还有就是类名的头一个字母最好大写要养成良好的习惯
请问一般出现下面的错误提示是怎么产生的? at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
郁闷死了,害的以为写错了,后来多了,也麻木了.于是删除重装JAVA,还是这样.好痛苦啊