sanjiao.java

Java 图形界面入门实例

import java.io.*;

public class sanJiao
{  public int intInput(String str)  throws IOException
   {  int row;
      InputStreamReader ir;
      BufferedReader in;
      ir=new InputStreamReader(System.in);
      in=new BufferedReader(ir);
      System.out.print(str);
      String s=in.readLine();
      row=Integer.parseInt(s);
      return row;
    }
    
    public void draw(int row)  throws IOException
    {  while(row%2==0)
       {  System.out.print("输入错误!\n请输入一个奇数: ");
          row=intInput(" ");
       }
       for(int i=1;i<=row/2+1;i++)
       {   for(int j=1;j<=row/2-i+1;j++)
              System.out.print("  ");
           for(int k=1;k<=2*i-1;k++)
              System.out.print("* ");
           System.out.println();
       }
       for(int i=1;i<=row-row/2+1;i++)
       {   for(int j=1;j<=i;j++)
              System.out.print("  ");
           for(int k=1;k<=2*(row/2+1-i)-1;k++)
              System.out.print("* ");
           System.out.println();
       }
     }
     
     public static void main(String args[]) throws IOException
     {  sanJiao sj=new sanJiao();
        int num;
        while(true)
        {   num=sj.intInput("输入行数(行数为一奇数,输入0 退出): ");
            if(num==0)
               break;
            else
               sj.draw(num);
         }
         System.out.println("该程序结束!");
      }
}