public String toString() { return "Emp [empno=" + empno + ", ename=" + ename + ", job=" + job + ", sal=" + sal + "]"; } public Emp() { this(-1, "无名氏", "未指定", 0); } public Emp(long empno)//接收参数,通过this调用其他构造函数并传递参数 { this(empno,"无名氏","未指定",0); } public Emp(long empno, String name) { this(empno, name, "未指定", 0); } public Emp(long empno, String ename, String job, float sal) { super(); this.empno = empno; this.ename = ename; this.job = job; this.sal = sal; }