为什么显示"选择未包含main 类型"(Eclipse提示)

[sunwxb]

public class Date{
private int day,month,year;
Date(int i,int j,int k){
day=i;
month=j;
year=k;

}
Date(){
day=12;
month=3;
year=1986;
}
Date(Date d){
day=d.day;
month=d.month;
year=d.year;
}
public void printDate(){
System.out.print(day +"/" +month +"/" +year);
}
public Date tomorrow(){
Date d=new Date(this);
d.day ++;
if(d.day>d.daysInMonth()){
d.day=1;
d.month++;
if(d.month>12){
d.month=1;
d.year++;
}
}
return d;
}
public int daysInMonth(){
switch(month){
case 1:case 3:case 5:case 7:case 8:case 10:case 12:
return 31;
case 4:case 6:case 9:case 11:
return 30;
default:
if(year%100!=0&&year%4==0){
return 29;
}
else return 28;
}

}
public void main(String args[]){
Date d1=new Date();
System.out.print("The current date is (dd/mm/yy/):");
d1.printDate();
System.out.println();
System.out.print("It's tomorrow is(dd/mm/yy/");
d1.tomorrow().printDate();
System.out.println();

Date d2=new Date(23,9,2009);
System.out.println("The current date is (dd/mm/yy");
d2.printDate();
System.out.println();
System.out.print("It's tomorrow is (dd/mm/yy)");
d2.tomorrow().printDate();
System.out.println();

}


}

[zidane1983]

注意public static void main(String args[])，main函数没有加static修饰符。

[sunwxb]

Exception in thread "main" java.lang.Error: 无法解析的编译问题：
方法 main 不能声明为“静态”；只能在静态类型或顶级类型中才能声明静态方法

at Date$TimeApp.main(Date.java:54)




这又是怎么回事呢？

[sunwxb]

Could not find the main class:Date$TimeApp.program will exit.


还是这样提示

[zidane1983]

[Quote=引用 2 楼 sunwxb 的回复:]
Exception in thread "main" java.lang.Error: 无法解析的编译问题：
方法 main 不能声明为“静态”；只能在静态类型或顶级类型中才能声明静态方法

at Date$TimeApp.main(Date.java:54)


这又是怎么回事呢？
[/Quote]

我整理了一下你的代码，你自己看看吧，运行没问题。

public class Date{
	private int day,month,year;
	Date(int i,int j,int k){
		day=i;
		month=j;
		year=k;
	}
	Date(){
		day=12;
		month=3;
		year=1986;
	}
	Date(Date d){
		day=d.day;
		month=d.month;
		year=d.year;
	}
	public void printDate(){
		System.out.print(day +"/" +month +"/" +year);
	}
	public Date tomorrow(){
		Date d=new Date(this);
		d.day ++;
		if(d.day>d.daysInMonth()){
			d.day=1;
			d.month++;
			if(d.month>12){
			d.month=1;
			d.year++;
			}
		}
		return d;
	}
	public int daysInMonth(){
		switch(month){
			case 1:case 3:case 5:case 7:case 8:case 10:case 12:
			return 31;
			case 4:case 6:case 9:case 11:
			return 30;
			default:
			if(year%100!=0&&year%4==0){
				return 29;
			}
			else return 28;
		}
	}
	public static void main(String args[]){
		Date d1=new Date();
		System.out.print("The current date is (dd/mm/yy/):");
		d1.printDate();
		System.out.println();
		System.out.print("It's tomorrow is(dd/mm/yy/");
		d1.tomorrow().printDate();
		System.out.println();
	
		Date d2=new Date(23,9,2009);
		System.out.println("The current date is (dd/mm/yy");
		d2.printDate();
		System.out.println();
		System.out.print("It's tomorrow is (dd/mm/yy)");
		d2.tomorrow().printDate();
		System.out.println();
	}
} 

[sunwxb]

非常感谢"zidane1983"
测试成功了
刚才应该是我在设置JRE参数时出现错误
现在纠正过来了，在次表示感谢 ！