POST 请求 servlet returns GET 方法的结果

Question

背景：

我正在编写一个 servlet 应用程序并希望有一个 servlet 处理 GET 和 POST 请求。该 servlet 内置于 WAR 文件中，并使用 Tomcat 服务器在我的开发机器 (localhost:8080) 上进行本地托管以进行测试。

对 servlet 的 GET 请求工作正常（returns index.jsp 页面），而 POSTing 到相同的 url 则运行 doPost() 方法中的代码（也是 return 的 index.jsp 页面）。

这是我的 servlet class 代码：

public class SelfserviceServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        RequestDispatcher view = request.getRequestDispatcher("/WEB-INF/index.jsp");
        view.forward(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String ip_address = request.getParameter("someparam");
        String port = request.getParameter("someotherparam");

        // Do some operation here to produce html_output

        response.setContentType("text/plain");
        response.setCharacterEncoding("UTF-8");
        response.getWriter().write(html_output.toString());
    }
}

这是我的 web.xml 文件：

    <servlet>
        <servlet-name>SelfservicePortal</servlet-name>
        <servlet-class>com.somename.module.SelfserviceServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>SelfservicePortal</servlet-name>
        <url-pattern>/portal</url-pattern>
    </servlet-mapping>

编辑：这是 index.jsp 文件：

<html>
<head>
<script>
    function sendPOST(){
        // First URL try
        $.ajax({
                url: "/SelfservicePortal",
                type: "POST",
                contentType: "application/x-www-form-urlencoded",
                data: "someparam=" + encodeURIComponent(someparam) + "&someotherparam=" + encodeURIComponent(someotherparam),
                success: function(data) {
                    alert(data);
                },
                error: function() {
                    alert("Error");
                }
            });
        // Second URL try
        $.ajax({
                url: "/SelfservicePortal/portal/",
                type: "POST",
                contentType: "application/x-www-form-urlencoded",
                data: "someparam=" + encodeURIComponent(someparam) + "&someotherparam=" + encodeURIComponent(someotherparam),
                success: function(data) {
                    alert(data);
                },
                error: function() {
                    alert("Error");
                }
            });
}
</script>
<body>
     <button type="button" onclick="sendPOST();">Send POST</button>
</body>
</html>

这些是我的结果：

GET localhost:8080/SelfservicePortal -> index.jsp

GET localhost:8080/SelfservicePortal/portal -> 404 未找到

POST localhost:8080/SelfservicePortal -> index.jsp [这应该是 html_output]

POST localhost:8080/SelfservicePortal/portal -> 404 未找到

如何使 POST 请求正常工作以及为什么对 url 映射模式的请求 return 是 404？

Answer 1

我想你忘了在你的 servlet 中添加注释尝试使用下面的代码看看它是否有效。如果要使用表单数据而不是 url 编码数据，还可以添加 @MultipartConfig。

    @WebServlet("/portal")    
    @MultipartConfig
    public class SelfserviceServlet extends HttpServlet {

            @Override
            protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                RequestDispatcher view = request.getRequestDispatcher("/WEB-INF/index.jsp");
                view.forward(request, response);
            }

            @Override
            protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                String ip_address = request.getParameter("someparam");
                String port = request.getParameter("someotherparam");

                // Do some operation here to produce html_output

                response.setContentType("text/plain");
                response.setCharacterEncoding("UTF-8");
                response.getWriter().write(html_output.toString());
            }
        }

POST 请求 servlet returns GET 方法的结果

POST request to servlet returns result of GET method

java

post

jsp

servlets

get