Question

您好，

1. 我将此表单发送到测试Sandbox Paypal服务器

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Start page</title>
</head>
<body>
<form method=post action=https://api-3t.sandbox.paypal.com/nvp>
        <input type=hidden name=USER value=my_sandbox_account>
        <input type=hidden name=PWD value=my_pass>
        <input type=hidden name=SIGNATURE value=my_sign_key>
        <input type=hidden name=VERSION value=72.0>
        <input type=hidden name=PAYMENTREQUEST_0_PAYMENTACTION
            value=Sale>
        <input name=PAYMENTREQUEST_0_AMT value=6.00>
        <input type=hidden name=RETURNURL
            value=http://www.my_return_url.com>
        <input type=hidden name=CANCELURL
            value=http://www.my_return_url.com>
        <input type=submit name=METHOD value=SetExpressCheckout>
</form>
</body>
</html>

2. 一旦我提交了该表单，我会在浏览器中收回字符串，如下所示：

TOKEN=EC%23409823094JKK&TIMESTAMP=2013%2d04%2d25T10%3a30%3a54Z&CORRELATIONID=345803985njkk3&ACK=Success&VERSION=72%2e0&BUILD=5709304

3。我希望我的servlet在我的变量中获取这个返回的字符串，我可以进一步管理它

    import java.io.IOException;

    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;

    /**
     * Servlet implementation class SetExpressCheckoutServlet
     */
    @WebServlet("/SetExpressCheckoutServlet")
    public class SetExpressCheckoutServlet extends HttpServlet {
        private static final long serialVersionUID = 1L;

        /**
         * @see HttpServlet#HttpServlet()
         */
        public SetExpressCheckoutServlet() {
            super();
            // TODO Auto-generated constructor stub
        }

        /**
         * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            doPost(request, response);
        }

        /**
         * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

            String token = request.getQueryString();
            System.out.println(token.toString());
        }

    }

当我启动项目时，它只传递步骤1和2，但3不通过。

请帮我正确创建servlet。

更新

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    String token = request.getParameter("TOKEN");
    PrintWriter pw = response.getWriter();
    if(token == null){
        System.out.println("It is null");
    } else {
        pw.print("<html><body>" + token + "<body></html>");
    }

}

我的web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app 
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    version="3.0" metadata-complete="true">

  <display-name>Ppconnector</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
  </welcome-file-list>


  <servlet>
    <servlet-name>SetExpressCheckoutServlet</servlet-name>
    <servlet-class>ua.pp.connector.SetExpressCheckoutServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>SetExpressCheckoutServlet</servlet-name>
    <url-pattern>/SetExpressCheckoutServlet</url-pattern>
  </servlet-mapping>


</web-app>

Answer 1

您想要的是使用ServletRequest#getParameter(String name)通过已知参数名称获取参数值。参数是get请求中的name=value对，可以通过调用getParameter方法在servlet中检索它们。所以，在你的情况下，它是：

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    String token = request.getParameter("TOKEN");
    //retrieve other parameters in a same way
    //and handle parameters accordingly
}

对于要调用的servlet，您的请求URL必须路径通过@WebServlet anotation声明您的案例中的servlet的url-mappling。

此外，如果您不需要get方法 - 请勿使用它。否则，更好的做法是get和post方法都可以调用processRequest(...)等常用函数。

使用servlet获取从Web站点返回的参数

1 个答案: