ServletContext 上下文 数据存储共享

三个必要步骤：

1：存储数据：

1 @Override
2     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
3 
4         ServletContext context = this.getServletContext();
5 
6         String username = "秦疆";
7         context.setAttribute("username", username);
8 
9     }
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2：读取数据：

1 @Override
2     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
3         ServletContext context = this.getServletContext();
4         String username = (String) context.getAttribute("username");
5 
6         resp.setContentType("text/html");
7         resp.setCharacterEncoding("utf-8");
8         resp.getWriter().print("名字" + username);
9     }
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3：加映射：

 1 <web-app>
 2   <display-name>Archetype Created Web Application</display-name>
 3   
 4   <servlet>
 5     <servlet-name>hello</servlet-name>
 6     <servlet-class>com.kuang.servlet.HelloServlet</servlet-class>
 7   </servlet>
 8   
 9   <servlet-mapping>
10     <servlet-name>hello</servlet-name>
11     <url-pattern>/hello</url-pattern>
12   </servlet-mapping>
13   
14   <servlet>
15     <servlet-name>getc</servlet-name>
16     <servlet-class>com.kuang.servlet.GetServlet</servlet-class>
17   </servlet>
18   
19   <servlet-mapping>
20     <servlet-name>getc</servlet-name>
21     <url-pattern>/getc</url-pattern>
22   </servlet-mapping>
23 </web-app>
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posted @ 2021-03-13 23:09  现在开始JAVA  阅读(113)  评论(0)    收藏  举报