java运行出错!!

class StudNode{
String name;
int studentNo;
double score;
StudNode next;
public StudNode(){}
public StudNode(String name,int studentNo,double score){
this.name=name;
this.studentNo=studentNo;
this.score=score;
}
public void setName(String name){
this.name=name;
}
public void setStudentNo(int studentNo){
this.studentNo=studentNo;
}
public void setScore(double score){
this.score=score;
}
public void setNext(StudNode node){
this.next=node;
}
public String getName(){
return name;
}
public int getStudentNo(){
return studentNo;
}
public double getScore(){
return score;
}
public StudNode getNext(){
return next;
}
public String toString(){
return studentNo+","+name+","+score;
}
}
interface StudOPeration{
void add(StudNode n

java 运行出错啦 java运行出错 运行java的class文件时出错！ JAVA编译成功，但运行出错？ java编译成功，但运行总是出错 java 程序运行出错,高手请进! java运行结果出错的具体原因 java:程序运行中出错，不明白为什么错了． 我在dos下运行*.java成绩为什么总出错? jdk的环境变量设置后,运行java程序总是出错