java 数字金字塔

public class a{
public static void main(String[] args) {

int i=1;
for (i=1;i<=9;i++)
{
for (int k=1;k<=9-i;k++)
{
System.out.print(" ");
}
for (int j=i;j>=1;j--)
{
System.out.print(j);
}
for (int j=2;j<=i;j++)
{
System.out.print(j);
}
System.out.println();
}
}

}