Passing Objects between Servlets

In this example we will see how to create class files, create objects with user input values and pass object from one servlet to another.

Step 1 : Create Java Class File.
Objects are an instance of a Class. So, we need a class file as a structure to create objects from user input values.

Create a java class file named "User.java".

public class User {
   private String name;
   private String email;
   public User(String n, String e) {
     this.name = n;
     this.email = e;
   }
   public String getName() {
     return name;
   }
   public String getEmail() {
     return email;
   }
}


Step 2 : Create HTML or JSP page to accept user input.

Enter the following code in the body tag of your code

<form action="servlet1">
  Name : <input type="text" name="username"/>
<br/>
  Email ID : <input type="text" name="emailid"/>
<br/>
<input type="submit" value="OK"/>
</form>


Step 3 : Create First Servlet to create object and store the user input values.(in my case named "servlet1").

Enter the following code in the doGet() of the servlet.


//assuming request as the object of the HttpServletRequest Class.
//assuming response as the object of the HttpServletResponse Class.

//creating an object named "newUser" of the class User & passing user input values as parameter to the constructor.

User newUser = new User(request.getParameter("username"),request.getParameter("emailid"));

//set a string value (eg."userData") for the object "newUser" to be able to access it from another servlet.

request.setAttribute("userData", newUser);

//passing the control to the second servlet named "servlet2"  using RequestDispatcher.

RequestDispatcher rd = request.getRequestDispatcher("servlet2");
rd.forward(request, response);

Step 4 : Create Second Servlet to retrive object data and display it to the user.

Enter the following code in the doGet() of the servlet.


//assuming request as the object of the HttpServletRequest Class.
//assuming response as the object of the HttpServletResponse Class.

//get the "userData" attribute from servlet1 and store it in variable "u" of the type "User" created earlier.
//also do not forget to typecast the attribute to the desired type.

User u = (User) request.getAttribute("userData");

//finally print the values using the getter methods of the User Class.

response.getWriter().println("Name : " + u.getName());
response.getWriter().println("Email : " + u.getEmail());



Finally, run the HTML or JSP page.