Check to see if a string has the same amount of 'x's and 'o's. The method must return a boolean and

Check to see if a string has the same amount of 'x's and 'o's. The method must return a boolean and be case insensitive. The string can contain any char.

Examples input/output:

XO("ooxx") => true
XO("xooxx") => false
XO("ooxXm") => true
XO("zpzpzpp") => true // when no 'x' and 'o' is present should return true
XO("zzoo") => false

代码：

public class XO {
    //方法一
    public static boolean getXO (String str) {
        boolean flag=false;
        int oNum=0;
        int xNum=0;
        if((str.contains("o")||str.contains("O"))&&(str.contains("x")||str.contains("X"))){
            for(int i=0;i<str.length();i++){
                String o=str.charAt(i)+"";
                if(o.trim().equals("o")||o.trim().equals("O")){
                    oNum++;
                }
            }
            for(int i=0;i<str.length();i++){
                String x=str.charAt(i)+"";
                if(x.trim().equals("x")||x.trim().equals("X")){
                    xNum++;
                }
            }
            if(oNum==xNum){
                flag=true;
            }
        }else {
            flag=true;
        }
        if((str.contains("o")||str.contains("O"))&&!(str.contains("x")||str.contains("X"))){
            flag=false;
        }
        if(!(str.contains("o")||str.contains("O"))&&(str.contains("x")||str.contains("X"))){
            flag=false;
        }
        return flag;
    }

    //方法二
    public static boolean getXO2 (String str) {
        str = str.toLowerCase();
        return str.replace("o","").length() == str.replace("x","").length();

    }

    public static void main(String[] args) {
        System.out.println(getXO("xooxx"));
        System.out.println(getXO2("xooxx"));
    }
}