I am unsure of how to access a persistence entity from a JSP page?_问答_开发者

I am unsure of how to access a persistence entity from a JSP page?

开发者 https://www.devze.com 2022-12-31 00:50 出处：网络

I am just learning Java EE, I have created a Persistence entity for a User object, which is stored in the database. I am now trying to create a JSP page that will allow a client to enter a new User object into the System. I am unsure of how the JSP page interacts with the User facade, the tutorials are confusing me a little.

This is the code for the facade:

<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Add User to System</title>
</head>
<body>
    <h2>Add User</h2>
    <h3>Please fill out the details to add a user to the system</h3>
    <form action="">
        <label>Email:</label>
        <input type="text开发者_运维知识库" name="email"><br />
        <label>Password:</label>
        <input type="password" name="name"><br />
        <label>Name:</label>
        <input type="text" name="name"><br />
        <label>Address:</label>
        <input type="text" name="address"><br />
        <label>Type:</label>
        <select name="type">
            <option>Administrator</option>
            <option>Member</option>
        </select><br />
        <input type="submit" value="Add" name="add"/>
        <input type="reset" value="clear" />
    </form>
</body>

This is the code I have to add a new User object within the User facade class:

@Stateless
public class CinemaUserFacade {
    @PersistenceContext(unitName = "MonashCinema-warPU")
    private EntityManager em;

public void create(CinemaUser cinemaUser) {
    em.persist(cinemaUser);
}

I am finding it a little difficult to get my head around the whole MVC thing, getting there but would appreciate it if someone could turn the light on for me!

Your JSP is the view here. Your User entity is the model here. What's missing form the "MVC"? Right, the controller is missing. You need to develop (or introduce) a controller yet. Is this homework? Then probably just a simple Servlet is enough. But if this is the real work, then I recommend to have a look for a real MVC framework to ease all the work, for example Sun JSF (JavaServer Faces).

See also: