java - Need assistance in handling Alerts - waiting for alert to be present & Unhandled Alert exception -

i have below alert. problem is returning error on wait.until(expectedconditions.alertispresent()) line unhandledalertexception, though can see alert triggered on-screen. if remove unhandledalertexception, error have unhandledalertexception. can please provide solution this, , explanation understand happened? `

//alert     alert getalert() {         try{         alert alert = driver.switchto().alert();         string alertcheck = alert.gettext();         this.bcase = true;         system.out.println(alertcheck);         if(alertcheck.equals("define higher 0 quantity products")){             m.print("correct error message appeared! user cannot advance further!");         } else if(alertcheck.equals("invalid payment document number")){             m.print("correct error message appeared! user cannot advance further!");         }else if (alertcheck.equals("define rates products")){             m.print("correct error message appeared! user cannot advance further!");         } else if (alertcheck.equals("define delivery dates products")){             m.print("correct error message appeared! user cannot advance further!");         } else if(alertcheck.equals("not implemented yet - waiting delivery doc input")){             m.print("correct error message appeared! user cannot advance further!");         }else if (alertcheck.equals("you must upload invoice file!")){             m.print("correct error message appeared! user cannot advance further!");         } else if (alertcheck.equals("you must upload payment order file!")){             m.print("correct error message appeared! user cannot advance further!");         } else if (alertcheck.equals("invalid payment document date")){             m.print("correct error message appeared! user cannot advance further!");         } else if (alertcheck.equals("invalid payment document number")){             m.print("correct error message appeared! user cannot advance further!");}           else if (alertcheck.equals("invalid payment document date")){             m.print("correct error message appeared! user cannot advance further!");}          else if(driver.findelement(by.xpath("//*[@class='btn pull-left btn-default input-sm'][text()='open order request']")).isdisplayed()){             this.bcase = false;             m.print("(fail!!!) user can advance unselected/wrongly completed fields, though error message present! (fail!!!)");         }   else {m.print("(fail!!!) user cannot advance, there no pop-up message informing him of problem! (fail!!!)");}         driver.switchto().alert().accept();         return alert;         } catch (noalertpresentexception e){             m.print("(fail!!!) user can advance wrongly completed fields, without error popup inform them! (fail!!!)");             this.bcase = false;              return null;         } catch (unhandledalertexception f){             wait.until(expectedconditions.alertispresent());             alert alert = driver.switchto().alert();             string alertcheck = alert.gettext();             if (alertcheck.equals("you must upload invoice file! must upload payment order file!")){                 m.print("correct error message appeared! user cannot advance further!");             } else if(driver.findelement(by.xpath("//*[@class='btn pull-left btn-default input-sm'][text()='open order request']")).isdisplayed()){                 this.bcase = false;                 m.print("(fail!!!) user can advance unselected/wrongly completed fields, though error message present! (fail!!!)");             }driver.switchto().alert().accept();return null;         }     } 

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i think better approach handle alerts first wait alert appear, , handle it. can this, 2 methods:

public boolean checknativealert() {     boolean exist = false;      try {         webdriverwait wait = new webdriverwait(webdriver, 3);         if(!(wait.until(expectedconditions.alertispresent()) == null)) {             exist = true;         }     }     catch (exception ignore) {}      return exist; }  public string getnativetextalert(boolean close) {     string text = null;     try {         alert alert = webdriver.switchto().alert();         text = alert.gettext();         if (close) {             alert.accept();         }     }     catch (exception ignore) {}      return text; } 

handle alerts selenium bit tricky, point of view better use 2 other options:

• change alerts modal dialogs (at least in debug/test mode)
• use autoit handle alerts in selenium tests