Question

我正在使用jsp将表单发送到servlet。在服务器端，处理完成，然后我想向用户发出警报，通知他是否成功。问题是我没有警报但也没有例外。当帖子结束时，我看到（虽然我不想）浏览器网址上的表单值如get ....这是代码

<form id="register" class="form-signin" >
<h2 class="form-signin-heading">Register here</h2>
First Name:<input type="text" name="firstName" class="input-block-level" placeholder="user name" required><br>
Last Name:<input type="text" name="lastName" class="input-block-level" placeholder="user name" required><br>
User Name:<input type="text" name="user" class="input-block-level" placeholder="user name" required><br>
Password:<input type="password" name="password" class="input-block-level" placeholder="Password" required><br>
Retype Password:<input type="password" name="retypedPassword" class="input-block-level" placeholder="Password" required><br>
Email:<input type="email" name="email" class="input-block-level" placeholder="email required"><br>
Retype Email:<input type="email" name="retypedEmail" class="input-block-level" placeholder="email required"><br>
<input type="submit" value="submit" id="submitButton" class="btn btn-primary">

</form>
<script type="text/javascript">
 $(document).ready(function(){
    $("#submitButton").on("click", function(){

     $.ajax({
            type: "POST",
            url: "RegisterServlet", //process to mail
            data: $("#register").serialize(),
            success: function(msg){

                alert(msg);
            },
            error: function(){
                alert("failure editing account. User name already taken");
            }
        });

});

});

</script>

在服务器端

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    String firstName = request.getParameter("firstName");
    String lastName = request.getParameter("lastName");
    String username = request.getParameter("user");
    String password = request.getParameter("password");
    String retypedPassword = request.getParameter("retypedPassword");
    String email =request.getParameter("email");
    String retypedEmail = request.getParameter("retypedEmail");
    String hash = UUID.randomUUID().toString();
    if(firstName == null || firstName.equals("")){
        errorMsg = "First name can't be null or empty.";
    }
    if(lastName == null || lastName.equals("")){
        errorMsg = "Last name can't be null or empty.";
    }
    if(username == null || username.equals("")){
        errorMsg = "User name can't be null or empty.";
    }
    if(password == null || password.equals("")){
        errorMsg = "Password can't be null or empty.";
    }
    if(retypedPassword == null || retypedPassword.equals("")){
        errorMsg = "Retype password can't be null or empty.";
    }
    if(email == null || email.equals("")){
        errorMsg = "Email can't be null or empty.";
    }
    if(retypedEmail == null || retypedEmail.equals("")){
        errorMsg = "Retyped email can't be null or empty.";
    }
    if(password.equals(retypedPassword)==false){
        errorMsg = "Passwords do not match.";
    }
    if(retypedEmail.equals(email)==false){
        errorMsg = " Emails are not the same.";
    }
    if(errorMsg != null){
        response.setContentType("text/plain");  // Set content type of the response so that jQuery knows what it can expect.
        response.setCharacterEncoding("UTF-8"); 
        response.getWriter().write(errorMsg);  

    }

但即使我尝试，我也什么也得不到。这段代码有什么问题？为什么提交后我会在网址上看到参数？

Answer 1

为什么提交后我会在网址上看到参数？

您可以在URL中看到这些参数，因为您的表单未使用ajax（jquery）提交，您必须在表单上使用submit处理程序，而不是单击按钮上的处理程序。

当您在submit按钮上绑定点击事件时，在到达jquery之前提交您的表单。

使用此e.preventDefault();来阻止默认提交表单。

而不是使用submit按钮点击处理程序：

$("#submitButton").on("click", function(){
  //your code
}

使用form提交处理程序：

$('#register').on("submit", function(e) {
  e.preventDefault();//preventing default submission 
  //your code
}

Answer 2

看起来您的表单是通过''控件提交来代替您的javascript。表单的默认方法是GET（请参阅here以获得一个很好的解释），这就是您在地址栏中看到参数的原因。

将输入类型从submit更改为button，或将<input>替换为<button>，您可以更加严格地控制正在发生的事情。

Answer 3

问题在于您的注册表格已提交且您的ajax调用失败。

我看到（虽然我不想）浏览器上表单的值网址就像一个获取

由于表单已提交且未指定方法，因此默认情况下get会导致通过url发送参数。

请改为尝试：

$(document).ready(function(){
  $("#register").on("submit", function(){
    /* to do here */
    return false;// restricts form submit
  }
};

jsp用jquery发布到servlet

3 个答案: