java(자바)에서 alert띄우기

java(자바)에서 alert띄우기

1.방법

if("NG"=="NG"){
    response.setContentType("text/html; charset=UTF-8");
    PrintWriter out = response.getWriter();
    out.println("<script>alert('엑셀파일을 확인해주세요.'); history.go(-1);</script>");
    out.flush();
    response.flushBuffer();
    out.close();
  }

기존방법을 사용할때

  -java.lang.IllegalStateException: Cannot call sendRedirect() after the response has been committed

  -에러가 발생할수 있다.

 

2.방법

if(excelInsert=="NG"){
    Writer out = response.getWriter();
    String message = URLEncoder.encode("엑셀파일을 확인해주세요.","UTF-8");
    response.setContentType("text/html; charset=UTF-8");
    out.write("<script type=\"text/javascript\">alert(decodeURIComponent('"+message+"'.replace(/\\+/g, '%20'))); location.href='/admin/main.do?mnu_url=/admin/civilOrganList.do&mnu_cd="+civilOrganVo.getMnu_cd()+"'</script>");
    out.flush();
    response.flushBuffer();
    out.close();
    return null;
  }

 

3.메서드로 만들기

*알림창만 띄우기*

-알림창 표시만 해준다

//알림창만 띄우기
public static void alert(HttpServletResponse response, String msg) {
    try {
		response.setContentType("text/html; charset=utf-8");
		PrintWriter w = response.getWriter();
		w.write("<script>alert('"+msg+"');</script>");
		w.flush();
		w.close();
    } catch(Exception e) {
		e.printStackTrace();
    }
}

*알림창 띄우고 창닫기*

-알림창 표시후 창을 닫는다

public static void alertAndClose(HttpServletResponse response, String msg) {
    try {
        response.setContentType("text/html; charset=utf-8");
        PrintWriter w = response.getWriter();
        w.write("<script>alert('"+msg+"');window.close();</script>");
        w.flush();
        w.close();
    } catch(Exception e) {
        e.printStackTrace();
    }
}

*알림창 띄우고 이전화면 이동*

-알림창 표시후 이전 화면으로 이동

public static void alertAndBack(HttpServletResponse response, String msg) {
    try {
        response.setContentType("text/html; charset=utf-8");
        PrintWriter w = response.getWriter();
        w.write("<script>alert('"+msg+"');history.go(-1);</script>");
        w.flush();
        w.close();
    } catch(Exception e) {
        e.printStackTrace();
    }
}

*알림창 띄우고 화면 이동*

-알림창 표시후 원하는 화면으로 이동

public static void alertAndGo(HttpServletResponse response, String msg, String url) {
    try {
        response.setContentType("text/html; charset=utf-8");
        PrintWriter w = response.getWriter();
        w.write("<script>alert('"+msg+"');location.href='"+url+"';</script>");
        w.flush();
        w.close();
    } catch(Exception e) {
        e.printStackTrace();
    }
}