重写toString老是报错，请指点迷津
public class DateSort{
  public static void main(String[] args){
  Date[] days = new Date[4];
  days[0]=new Date(1999,3,22);
  days[1]=new Date(1989,3,12);
  days[2]=new Date(1999,8,22);
  days[3]=new Date(1909,3,2);
   
  sort(days);
   
  for(int i=0;i<days.length;i++){
  System.out.println(days[i]);
  }
  }

  public static Date[] sort(Date[] a){
  for(int i=a.length-1;i>=1;i--){
  for(int j=0;j<=i-1;j++){
  if(a[j].compare(a[j+1])>0){
  Date temp=a[j];
  a[j]=a[j+1];
  a[j+1]=temp;
  }
  }
  }
  return a; 
  } 
}  
class Date{
  int year,day,month;
  Date(int y,int m,int d ){
  this.year=y; this.month=m;this.day=d;
  }
  
   
   
  public int compare(Date date){  
  return year>date.year ? 1 
  : year<date.year ? -1
  : month>date.month ? 1
  : month<date.month ? -1
  : day>date.day ? 1 
  : day<date.day ? -1:0;
  }
  
  public String toString() {
  return "Year:Month:Day--" + year"-" + month "-" + day;
  }
  
}

------解决方案--------------------
+ year"-" + month "-"



这两处算怎么回事？！
------解决方案--------------------
应该改成这样："Year:Month:Day--" + year+"-" + month +"-" + day;