Servlet：属性介绍

原文：https://www.studytonight.com/servlet/attribute.php

属性是用于在网络应用中共享信息的对象。属性允许 Servlets 之间共享信息。可以从以下范围之一设置和获取属性:

1. 请求
2. 会议
3. 应用

Servlet:如何设置属性

public void setAttribute(String name, Object obj)方法用于设置属性。

设置属性演示示例

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class First extends HttpServlet {

  protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        ServletContext sc = getServletContext();
        sc.setAttribute("user","Abhijit");    //setting attribute on context scope
    }
}

Servlet:如何获取属性

Object getAttribute(String name)方法用于获取属性。

演示获取集合属性值的示例

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class Second extends  HttpServlet {

  protected void  doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        ServletContext sc = getServletContext();

        String str = sc.getAttribute("user");  //getting attribute from context scope

        out.println("Welcome"+str);  // Prints : Welcome Abhijit   
    }
}