Java项目中每一个类都可以有一个main方法，但只有一个main方法会被执行，其他main方法可以对类进行单元测试。
public class StaticTest {
public static void main(String[] args)
{
Employee[] staff=new Employee[3];
staff[0]=new Employee("Tom",40000);
staff[1]=new Employee("Dick",60000);
staff[2]=new Employee("Harry",65000);
for(Employee e:staff)
{
e.setId();
System.out.println("name="+e.getName()+",id="+e.getId()+",salary="+e.getSalary());
}
int n=Employee.getNextId();
System.out.println("Next available id="+n);
}
}
class Employee
{
public Employee(String n,double s)
{
name=n;
salary=s;
id=0;
}
public String getName()
{
return name;
}
public double getSalary()
{
return salary;
}
public int getId()
{
return id;
}
public void setId()
{
id=nextId;
nextId++;
}
public static int getNextId()
{
return nextId;
}
public static void main(String[] args)
{
Employee e=new Employee("Harry",50000);
System.out.println(e.getName()+" "+e.getSalary());
}
private String name;
private double salary;
private int id;
private static int nextId=1;
}
java Employee可以得到
Harry 50000.0
java StaticTest可以得到
name=Tom,id=1,salary=40000.0
name=Dick,id=2,salary=60000.0
name=Harry,id=3,salary=65000.0
Next available id=4