java核心技术(卷I)205页,源码:
以下代码,想实现按工资从小到大排序输出,能通过编译,但运行有问题,为什么呢?
import java.util.*;
public class EmployeeTest
{
public static void main(String[] args)
{
Employee[] workers = new Employee[3];
workers[0] = new Employee( "tamik ",2000,1999,7,8);
workers[1] = new Employee( "Yu dan ",2800,1994,7,8);
workers[2] = new Employee( "John Rose ",2600,2001,7,8);
for( int nI=0; nI <3; nI++)
workers[nI].raiseSalary(5);
for( Employee e : workers)
System.out.println( "name= "+e.getName()
+ ",salary= "+e.getSalary()
+ ",hireDay= "+e.getHireDay());
Arrays.sort(workers); //按工资排序
for( Employee e : workers)
System.out.println( "name= "+e.getName()
+ ",salary= "+e.getSalary()
+ ",hireDay= "+e.getHireDay());
}
}
class Employee implements Comparable
{
public Employee(String s, double dbNum, int year,int month,int day)
{
name = s;
salary = dbNum;
GregorianCalendar time=new GregorianCalendar(year,month-1,day);
hireDay = time.getTime();
}
public String getName()
{
return name;
}
public Date getHireDay()
{
return hireDay;
}
public double getSalary()
{
return salary;
}
public void raiseSalary(double percent)
{
salary *=1+percent/100;
}
public int compareTo(Object other)
{
Employee other2 = (Employee)other;
if(this.salary > other2.salary) return 1;
if(this.salary < other2.salary) return -1;
return 0;
}
private String name; //姓名
private double salary; //工资
private Date hireDay; //雇用日期
}
用以下代码,问题同样:
import java.util.*;
public class EmployeeTest
{
public static void main(String[] args)
{
Employee[] workers = new Employee[3];
workers[0] = new Employee( "tamik ",2000,1999,7,8);
workers[1] = new Employee( "Yu dan ",2800,1994,7,8);
workers[2] = new Employee( "John Rose ",2600,2001,7,8);
for( int nI=0; nI <3; nI++)
workers[nI].raiseSalary(5);
for( Employee e : workers)
System.out.println( "name= "+e.getName()
+ ",salary= "+e.getSalary()
+ ",hireDay= "+e.getHireDay());
Arrays.sort(workers); //按工资排序
for( Employee e : workers)
System.out.println( "name= "+e.getName()
+ ",salary= "+e.getSalary()
+ ",hireDay= "+e.getHireDay());
}
}
class Employee implements Comparable <Employee>
{
public Employee(String s, double dbNum, int year,int month,int day)