Java初学者错误1：incompatible types: boolean cannot be converted to int_incompatible types: statement cannot be converted

private static int get_wx_inx(String str) {
    boolean equalsIgnoreCase = str.equalsIgnoreCase("0");
    int equalsIgnoreCase2 = str.equalsIgnoreCase("1");
    if (str.equalsIgnoreCase("2")) {
        equalsIgnoreCase2 = true;
    }
    if (str.equalsIgnoreCase("3")) {
        equalsIgnoreCase2 = 3;
    }
    return str.equalsIgnoreCase("4") ? 4 : equalsIgnoreCase2;
}

JDK版本问题，如果仍要使用该版本，则更正为：

private static int get_wx_inx(String str) {
        if(str.equalsIgnoreCase("0")) {
            return 0;
        } else if(str.equalsIgnoreCase("1")) {
            return 1;
        }else if(str.equalsIgnoreCase("2")) {
            return 2;
        } else if(str.equalsIgnoreCase("3")) {
            return 3;
        } else if(str.equalsIgnoreCase("4")) {
            return 4;
        } else {
            return 0;// write default return here. If every condition goes false then this default will be return.
        }
    }