从 JavaScript 调用 Servlet
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Calling Servlet from JavaScript
提问by silver
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<input type="image">单击后调用一个 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):
小服务程序 ( 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
However, nothing happens when I click the image button. I am new to JavaScript.
上下文根：http://localhost:8080/mysite/test-servlet.jsp
但是，当我单击图像按钮时，没有任何反应。我是 JavaScript 的新手。
采纳答案by Roman C
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 doGetmethod is used to get the request from javascript.
最后我们发现 servlet 应该被映射而没有扩展名，并且doGet方法用于从 javascript 获取请求。
回答by Santhosh
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 imgtag with buttonas Roman says
并且还使用img标签 withbutton正如 Roman 所说
the url in the actionis called , when your form is being submitted
中的 urlaction被调用，当您的表单被提交时
so try replacing it with ,
所以尝试将其替换为，
<form action="./test-servlet" method="post">
and using your JavaScript now,
现在使用你的 JavaScript，
You cant use window.location.hrefto make a POSTrequest . check pass post data with window.location.href
你不能window.location.href用来提出POST请求。使用 window.location.href检查传递发布数据
<script type="text/javascript">
function callServlet() {
document.forms[0].submit;
}
</script>
