Stay on the same page after inserting into db

问题

I am making an insert into a database ,and after the operation is done,I want to stay on the same page and the results after inserting to be present.

Now after the inserting when I am trying to sent to the same page I got as result the page without any data.

Here is my java code:

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 try{

            DBConnection connection = new DBConnection();
            Connection con = connection.Connect();


         PreparedStatement ps=con.prepareStatement("INSERT into nota (Id_utilizator,Nume_reteta,Nota) values ((SELECT Id_user from user where E_mail = '"+request.getSession().getAttribute("email")+"'),(SELECT Nume FROM reteta where Nume = '"+retetaid+"'),('"+nota+"'))");
         ps.executeUpdate();
         String destination = "/Retete";
         RequestDispatcher rd = request.getRequestDispatcher(destination);
         rd.forward(request, response);

       con.close();
       ps.close();
       }
       catch (Exception e2)
       {
         e2.printStackTrace();
       }

       finally
       {
       out.close();
        }
    }

Here is my jsp form where is called my method:

  <form action = "Nota" method="post">                                  
    <div class="grid_6"> 
    <input type="hidden" name="reteta1"  value="${Nume} "/> 
    <input   type="submit" name="nota" class="btnrtg" value="Acorda Nota!"/> 
    <input class="star star-5" id="star-5" type="radio" name="mark" value="100"/>
    <label class="star star-5" for="star-5"></label>
    <input class="star star-4" id="star-4" type="radio" name="mark" value="75"/>
    <label class="star star-4" for="star-4"></label>
    <input class="star star-3" id="star-3" type="radio" name="mark" value="50"/>
    <label class="star star-3" for="star-3"></label>
    <input class="star star-2" id="star-2" type="radio" name="mark" value="25"/>
    <label class="star star-2" for="star-2"></label>
    <input class="star star-1" id="star-1" type="radio" name="mark" value="0"/>
    <label class="star star-1" for="star-1"></label>    

    </div>
</form>

In "Retete" is another servlet wehere are made extracting from db operations.

Could anyone help me? Thanks.

回答1:

First of all the way you are doing is wrong still i have a solution for you. and also you don't have explained whole flow.

Still follow steps below it will make your code tightly coupled but still will work..

Add data extracting code in your java code after insertion and before forwarding that is

ps.executeUpdate();

//place your extracting code here

String destination = "/Retete";

Then add your extracted data to a variable
again add it to response
Then on your jsp page show that data

Finally your should look like this

DBConnection connection = new DBConnection();

Connection con = connection.Connect();

PreparedStatement ps=con.prepareStatement("INSERT into nota (Id_utilizator,Nume_reteta,Nota) values ((SELECT Id_user from user where E_mail = '"+request.getSession().getAttribute("email")+"'),(SELECT Nume FROM reteta where Nume = '"+retetaid+"'),('"+nota+"'))");

ps.executeUpdate();

String destination = "/Retete";

// Enter your data extraction logic here and save all your data to a single generic variable

// Now here add the variable to the request like request.setAttribute("variableName",variable);

RequestDispatcher rd = request.getRequestDispatcher(destination);

rd.forward(request, response);

But remember if you are redirecting to other servlet from here then don't put response.sendRedirect(""); statement in other servlet if you want this data in JSP And once again this is not the proper way to do it first refer MVC Design Pattern...

来源：https://stackoverflow.com/questions/37608960/stay-on-the-same-page-after-inserting-into-db

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java

jsp

servlets