JSP的pageContext对象实战

以你之姓@ 2021-07-24 14:05 383阅读 0赞

**一 代码**

<%@ page contentType="text/html; charset=GBK" language="java" errorPage="" %>
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml">
 <head>
 <title> pageContext测试 </title>
 <meta name="website" content="http://www.crazyit.org" />
 </head>
 <body>
 <%
 // 使用pageContext设置属性，该属性默认在page范围内
 pageContext.setAttribute("page","hello");
 // 使用request设置属性，该属性默认在request范围内
 request.setAttribute("request","hello");
 // 使用pageContext将属性设置在request范围中
 pageContext.setAttribute("request2","hello"
 , pageContext.REQUEST_SCOPE);
 // 使用session将属性设置在session范围中
 session.setAttribute("session","hello");
 // 使用pageContext将属性设置在session范围中
 pageContext.setAttribute("session2","hello"
 , pageContext.SESSION_SCOPE);
 // 使用application将属性设置在application范围中
 application.setAttribute("app","hello");
 // 使用pageContext将属性设置在application范围中
 pageContext.setAttribute("app2","hello"
 , pageContext.APPLICATION_SCOPE);
 //下面获取各属性所在的范围：
 out.println("page变量所在范围：" +
 pageContext.getAttributesScope("page") + " ");
 out.println("request变量所在范围：" +
 pageContext.getAttributesScope("request") + " ");
 out.println("request2变量所在范围："+
 pageContext.getAttributesScope("request2") + " ");
 out.println("session变量所在范围：" +
 pageContext.getAttributesScope("session") + " ");
 out.println("session2变量所在范围：" +
 pageContext.getAttributesScope("session2") + " ");
 out.println("app变量所在范围：" +
 pageContext.getAttributesScope("app") + " ");
 out.println("app2变量所在范围：" +
 pageContext.getAttributesScope("app2") + " ");
 %>
 </body>
 </html>

**二 测试**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70]: /images/20210724/196199edc33c4963999bee768dbb16f1.png