自定义异常，数值不能为负数。public class NoScoreException extends RuntimeException { public NoScoreException() { super(); } public NoScoreException(String message) { super(message); }}public class Student {private String name;private int score;public Student() {super(); }public Student(String name,int score){ setName(name); setScore(score); }public String getName() {return name; }public void setName(String name) {this.name = name; }public int getScore() {return score;}public void setScore(int score) {// 判断,如果score为负数,就抛出NoScoreException,异常信息为:分数不能为负数:xxx.if(score <0){ }this.score = score; }}