import java.util.Scanner;

public class Test
{

    static int[] guessNumber = new int[4]; // 保存玩家输入的数

    static Scanner s;

    static int i;

    public static void main(String[] args)
    {
        w();
    }

    public static void w()
    {    
        System.out.println("输入结束请按回车然后ctrl+z");
        
        StringBuffer sb = new StringBuffer();
        
        s = new Scanner(System.in);
        
        while (s.hasNext())
        {
            sb = sb.append(s.next() + " ");
        }
        
        if (4 != sb.toString().split(" ").length)
        {
            System.out.println("输入不正确");
        }
        else
        {
            System.out.println("输入正确");
            
            for (int i = 0; i < 4; i++)
            {
                guessNumber[i] = Integer.parseInt(sb.toString().split(" ")[i]);
            }
            
            System.out.print("数组内容为:  ");
            
            for (int number : guessNumber)
            {
                System.out.print(number + " ");
            }
        }
    }
}

------解决方案--------------------
经我测试了可以。。。  
package task;
import java.util.Scanner;

public class Panduan{

   static int[] guessNumber = new int[4]; // 保存玩家输入的数
  
   public static void main(String[] args)
   {
       w();
   }

   public static void w()
   {   
   	Scanner s = new Scanner(System.in);

       System.out.println("情输入四个数，按回车结束！");
  	 String  str = new String();
    str = s.nextLine();
       String str1[] = new String[4];
       str1 = str.split(" ");
      
       if (4 != str1.length)
       {
           System.out.println("请输入四个数！");
           return;
       }
       else
       {
           System.out.println("输入正确");
           String str2 ="";
          
           for (int i = 0; i < 4; i++)
           {
           	str2+=str1[i];
           }
           System.out.print("数组内容为:  "+str2);
         

       }
   }
}