求救Java编程 输入*号

public class Go{
public static void main(String args[]){
String str=new String("*");
System.out.println(str);
for(int i = 0;i<4;i++){
str+="**";
System.out.println(str);
}

}
}

String str = "*";
for(int i = 0;i<4;i++){
if(i>0){
str += "**";}
System.out.println(str);
}

import java.util.*;
public class Star{
public static void main(String args[]){
String str="* *** ***** *******";
StringTokenizer sr=new StringTokenizer(str);
while (sr.hasMoreTokens()) {
System.out.println(sr.nextToken());
}
}
}
楼主可以试试

public class Test{
public static void getOut(int n){
for(int i = 1; i <= n; i++){
for(int j = 1; j <=2*i-1; j++){
System.out.println("*");
}