servlets - 如何在servlet中获取路径变量值

Question

我想获取 servlet 中的路径变量。假设 url 是 www.demo.com/123/demo。我想从路径中获取 123 值而不进行任何字符串操作。

注意:以下 servlet 没有任何 web.xml 配置。我的代码是:

@WebServlet(urlPatterns = { "/demo" })
public class DemoServlet extends HttpServlet {

  public DemoServlet()
  {
      super();
  }

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

  protected void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException
  { 
      sysout("demo");       
  }
}

Answer 1

您所指的 URL 部分是“上下文”。使用 request.getContextPath() 获取它。对于您的示例，这将返回 /123。如果您想要 exactly 123，则必须删除前导斜杠。

来自documentation :

Returns the portion of the request URI that indicates the context of the request. The context path always comes first in a request URI. The path starts with a "/" character but does not end with a "/" character. For servlets in the default (root) context, this method returns "". The container does not decode this string.