*
***
*****
***
*
public class Test {
public static void main(String[] args) {
int n = 2; //除去中间的对称线,剩余的对称的有几行;
for (int i=-n;i<=n;i++){
for(int j=1;j<=Math.abs(i);j++){
System.out.print(" ");
}
for(int j=1;j<=2*(Math.abs(n)-Math.abs(i))+1;j++){
System.out.print("*");
}
System.out.println();
}
}
}