public class new4 {    //学生ID    public String id;    //学生姓名    public String name;    public new4(String idCard, String name) {        this.id = idCard;        this.name = name;    }    //重写equals方法    public boolean equals(Object obj) {        new4 e = (new4) obj;        if (id == null) {            if (e.id != null)                return false;        } else if (!id.equals(e.id))            return false;        if (name == null) {            if (e.name != null)                return false;        } else if (!name.equals(e.name))            return false;        return true;    }    public static void main(String[] args) {        new4 p1 = new new4("1001", "我帅");        new4 p2 = new new4("1001", "我丑");        System.out.println(p1.equals(p2));    }}