如何使用JSP从URL获取参数 [英] How to get parameters from the URL with JSP

问题描述

在JSP中如何从URL获取参数？

In JSP how do I get parameters from the URL?

例如我有一个URL www.somesite.com/Transaction_List.jsp ？accountID = 5

我想得到5.


是否有request.getAttribute（accountID）之类的会话或类似的东西？

For example I have a URL www.somesite.com/Transaction_List.jsp?accountID=5
I want to get the 5.

Is there a request.getAttribute( "accountID" ) like there is for sessions or something similar?

推荐答案

在GET请求中，请求参数取自查询字符串（数据）跟随URL上的问号）。例如，URL http://hostname.com?p1=v1&p2=v2包含两个请求参数 - - p1和p2。在POST请求中，请求参数来自查询字符串和在请求正文中编码的发布数据。

In a GET request, the request parameters are taken from the query string (the data following the question mark on the URL). For example, the URL http://hostname.com?p1=v1&p2=v2 contains two request parameters - - p1 and p2. In a POST request, the request parameters are taken from both query string and the posted data which is encoded in the body of the request.

此示例演示如何包含生成的输出中的请求参数的值：

This example demonstrates how to include the value of a request parameter in the generated output:

Hello <b><%= request.getParameter("name") %></b>!

如果使用网址访问该页面：

If the page was accessed with the URL:

http://hostname.com/mywebapp/mypage.jsp?name=John+Smith

结果输出为：

Hello <b>John Smith</b>!

如果未在查询字符串中指定name，则输出为：

If name is not specified on the query string, the output would be:

Hello <b>null</b>!

此示例使用scriptlet中查询参数的值：

This example uses the value of a query parameter in a scriptlet:

<%
    if (request.getParameter("name") == null) {
        out.println("Please enter your name.");
    } else {
        out.println("Hello <b>"+request. getParameter("name")+"</b>!");
    }
%>

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