成功属性无法在视图中触发

这些天我正在学习骨干JS，下面是无法在"编辑用户"中触发"成功"的代码

请告诉我我需要做哪些更改？

下面的代码是组合代码：

<script type="text/template" id="edit-user-template">
        <form class="edit-user-form" method="POST">
            <legend>Create New User</legend>
            <label>First Name</label>
            <input type="text" name="firstname" id="firstname"/>
            <label>Last Name</label>
            <input type="text" name="lastname" id="lastname" />
            <label>Age</label>  
            <input type="text" name="age" id="age" />
            <hr/>
            <input type="submit" value="Create User" />
        </form>
</script>

var User = Backbone.Model.extend({
            urlRoot: 'api/users'
})

var EditUser =  Backbone.View.extend({
            el: '.page',
            events:{
                'submit .edit-user-form':'saveUser'
            },
            saveUser : function(e){
                var user = new User();
                user.save({firstName: $('#firstname').val() ,lastName: $('#lastname').val() ,age: $('#age').val() },    
                    {
                     success :  function(user){
                        console.log('INSIDE SUCCESS..')
                        router.navigate('',{trigger:'true'});
                    }
                });
            },
            render: function(){
                var template = _.template($('#edit-user-template').html());
                this.$el.html(template);
            }
})

@POST
@Consumes({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
@Produces({ MediaType.APPLICATION_JSON })
public User create(User user) {
    return dao.create(user);
}

public User create(User user) {
Connection c = null;
PreparedStatement ps = null;
try {
    c = ConnectionHelper.getConnection();
    ps = c.prepareStatement("INSERT INTO user (firstname, lastname, age) VALUES (?, ?, ?)",
    new String[] { "ID" });
    ps.setString(1, user.getFirstName());
    ps.setString(2, user.getLastName());
    ps.setInt(3, user.getAge());
    ps.executeUpdate();
    ResultSet rs = ps.getGeneratedKeys();
    rs.next();
    // Update the id in the returned object. This is important as this value must be returned to the client.
    int id = rs.getInt(1);
    user.setId(id);
} catch (Exception e) {
    e.printStackTrace();
    throw new RuntimeException(e);
    } finally {
        ConnectionHelper.close(c);
    }
return user;
}

我已经在谷歌上搜索过，但仍然没有解决他们的建议。希望有人能清除我这个问题

更新：

public class User {
    private int id;
    private String firstName;
    private String lastName;
    private int age;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getFirstName() {
        return firstName;
    }
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
    public String getLastName() {
        return lastName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
}