从JavaScript调用Servlet

Question

I intend to call a function in JavaScript which then calls a Servlet after an <input type="image"> is clicked. 我打算在JavaScript中调用一个函数，然后在单击<input type="image">单击Servlet。

JSP: JSP：

<head>
    <script type="text/javascript">
        function callServlet() {
            document.location.href="test-servlet.jsp";
        }
    </script>
</head>

<body>
    <form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post">
    ...
    <input type="image" name="submit"
        src="https://www.paypalobjects.com/webstatic/en_US/btn/btn_buynow_pp_142x27.png"
        onclick="callServlet()" alt="PayPal - The safer, easier way to pay online!">
    </form>
</body>

Servlet ( test-servlet.jsp ): Servlet（ test-servlet.jsp ）：

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    response.setContentType("text/html");

    PrintWriter out = response.getWriter();

    out.println("<h1>TestServlet called successfully!</h1>");
}

Context Root: http://localhost:8080/mysite/test-servlet.jsp 上下文根： http://localhost:8080/mysite/test-servlet.jsp

However, nothing happens when I click the image button. 但是，当我单击图像按钮时，什么也没有发生。 I am new to JavaScript. 我是JavaScript新手。

Answer 1

Try this code 试试这个代码

<a href="#" onclick="callServlet()"><img
    src="https://www.paypalobjects.com/webstatic/en_US/btn/btn_buynow_pp_142x27.png"
    alt="PayPal - The safer, easier way to pay online!"></a>

EDIT: 编辑：

Finally we discovered that a servlet should be mapped without extension and doGet method is used to get the request from javascript. 最后，我们发现应该映射一个没有扩展名的servlet，并使用doGet方法从javascript获取请求。

Answer 2

I Could see multiple errors in your jsp . 我可以在您的jsp中看到多个错误。

First of all , 首先，

<form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post">

And also use the img tag with button as Roman says 并像罗马人所说的那样使用带有button的img标签

the url in the action is called , when your form is being submitted 提交表单时，该action的url被称为

so try replacing it with , 因此，请尝试将其替换为

<form action="./test-servlet" method="post">

and using your JavaScript now, 并立即使用您的JavaScript，

You cant use window.location.href to make a POST request . 您不能使用window.location.href发出POST请求。 check pass post data with window.location.href 使用window.location.href检查通行证数据

<script type="text/javascript">
    function callServlet() {
        document.forms[0].submit;
    }
</script>

从JavaScript调用Servlet

问题描述

2 个解决方案

解决方案1
1 已采纳 2014-11-03 11:32:43

解决方案2
1 2014-11-03 11:38:23

从JavaScript调用Servlet

问题描述

2 个解决方案

解决方案1 1 已采纳 2014-11-03 11:32:43

解决方案2 1 2014-11-03 11:38:23

解决方案1
1 已采纳 2014-11-03 11:32:43

解决方案2
1 2014-11-03 11:38:23