Why is my update button not working?

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Java

HTML

Hello, fairly new to coding here.
I basically want to
"Update" data that is connected to a mysql database
but i have a problem
is that , The Update Button is not working.

Heres my related codes

Keeper.java
This is where the update and getbyId is defined i really dont think that theres any problem here.
maybe i have some kind of format wrong on
"Update keeper set"

Update function

public int update(KeeperK c) throws ClassNotFoundException, SQLException{

			int result=-1;

			//1. get connection
			DBManager dbMgr=new DBManager();
			Connection conn=dbMgr.getConnection();

			//2.prepare statement

			String sql = "Update keeper Set keepername=?,keeperrank=?,dateofbirth=? where keeperID=?";

			PreparedStatement pstmt=conn.prepareStatement(sql);

			// first and second paramters inserted 1. course name and course text
			
			pstmt.setString(1, c.getKeeperName());
			pstmt.setString(2, c.getKeeperRank());
			pstmt.setString(3, c.getDateKeeper());
			pstmt.setString(4, c.getKeeperId());



			//3.execute statement

			result = pstmt.executeUpdate();

			return result;

			}

getById function

public KeeperK getById(String id) throws SQLException, ClassNotFoundException {
			String sql ;
			//1. get Connection
			DBManager dbMgr = new DBManager();
			Connection conn = dbMgr.getConnection();

			//2. prepare the statement
			sql = "SELECT * FROM keeper WHERE keeperID = ?" ;



			PreparedStatement pstmt = conn.prepareStatement(sql);
			//First parameter is the course id of the course entity
			pstmt.setString(1,id);
			ResultSet rs = pstmt.executeQuery();



			KeeperK course = null;



			while(rs.next()) {
			course = new KeeperK(rs.getString("keeperID"),
			rs.getString("keepername"),
			rs.getString("keeperrank"), rs.getString("dateofbirth"));
			}
			return course;
			
			}

course_list.jsp

so basically , this will open up a page that have all the data
and after clicking "Edit"

Another page will load.

		try {
			DBManager dbMgr = new DBManager();
			dbMgr.getConnection();
						
			Keeper dao = new Keeper();
			ArrayList<KeeperK> courses = dao.fetchAll();
%>			
			
            <table border="1">
	            <tr>
	                <th>Keeper Id</th>
	                <th>Keeper Name</th>
	                <th>Keeper Rank</th>
	                <th>Date of birth</th>
	                <th>Edit Keeper</th>
	                <th>Delete Keeper</th>
	            </tr>
<%            
			for (KeeperK course : courses) {
	             //out.println( course.getKeeper() + "\t" + course.getKeepername() + "\t" + course.getCourseText());
%>	             

		            
	             	<tr>
	             		<td> <%=course.getKeeperId()%> </td>
	             		<td> <%=course.getKeeperName()%> </td>
	             		<td> <%=course.getKeeperRank()%> </td>
	             		<td> <%=course.getDateKeeper()%> </td>
	             		
	             		<td><a href="edit_course.jsp?id=<%=course.getKeeperId()%>">Edit</a></td>
                    	<td><a href="delete_course.jsp?id=<%=course.getKeeperId()%>">Delete</a></td>
                    
	             	</tr>

edit_course.jsp
This will take another action from update_action.jsp
This is where i think the problem is but i cant find it ._.

<form method="POST" action="update_action.jsp"></form>
            <%
                String keeperID = request.getParameter("id");
                if (keeperID == null){
                    out.println("Keeper ID is not found");
                } else {
                    String id = keeperID;
                    Keeper dao = new Keeper();
                    try {
                        KeeperK c = dao.getById(id);
                        out.print(c);

            %>
                    <input type="hidden" name="keeperID" value="<%=c.getKeeperId()%>" />
                    <label for="keepername">Keeper Name</label>
                    <input type="text" name="keepername" id="keepername" value="<%=c.getKeeperName()%>" required/>
                    <label for="keeperrank">Keeper Rank</label>
                    <input type="text" name="keeperrank" id="keeperrank" value="<%=c.getKeeperRank()%>" />
                    <label for="dateofbirth">Date of birth</label>
                    <input type="text" name="dateofbirth" id="dateofbirth" value="<%=c.getDateKeeper()%>" />
                    <input type="submit" value="Update" />
            <%
                    }catch (ClassNotFoundException ex){
                      out.println( ex.getMessage());
                    }catch (SQLException e){
                      out.println(e.getMessage());
                    }
                }
            %>

update_action.jsp

<body>
<%
    String keeperID = request.getParameter("keeperID");
    String keepername = request.getParameter("keepername");
    String keeperrank = request.getParameter("keeperrank");
    String   dateofbirth = request.getParameter("dataofbirth");
    out.println (keeperID);
    out.println (keepername);
    out.println (keeperrank);
    out.println (dateofbirth);

            Keeper dao = new Keeper();
            KeeperK c = new KeeperK(keeperID, keepername, keeperrank, dateofbirth);
            int rowsAffected;
            try {

                rowsAffected = dao.update(c);
                out.println("No of rows affected - " + rowsAffected);

             }catch (ClassNotFoundException ex){
                  out.println( ex.getMessage());

              }catch (SQLException e){
                  out.println(e.getMessage());

              }
%>
</body>

What I have tried:

I tried changing , the input type="submit" value="Update" to
a button type but that also doesnt work.
It doesnt show errors either , it just kinda like not accpeting it?

telling me what could be wrong would help as well if you cant find a direct solution.