setAttribute方法共享数据

Mahe666

context.setAttribute("String",Object);

context.getAttribute("String");

键值对的方式实现跨越Servlet传输数据

例：

ServletContext context = this.getServletContext();

context.setAttribute("mh","mahe666");

String username = (String)context.getAttribute("mh");

System.out.println(username);

代码示例如下

GetServlet.java

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class SetServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ServletContext context = this.getServletContext();
        String username = "马赫666";
        context.setAttribute("username",username);
        System.out.println("Hello,Servlet02");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

SetServlet.java

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class GetServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        ServletContext context = this.getServletContext();
        String username = (String) context.getAttribute("username");

        resp.setContentType("text/html");
        resp.setCharacterEncoding("utf-8");
        resp.getWriter().println(" 名字 "+username);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
				http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0"
         metadata-complete="true">

    <servlet>
        <servlet-name>setC</servlet-name>
        <servlet-class>com.mahe666.servlet.SetServlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>setC</servlet-name>
        <url-pattern>/setC</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>getC</servlet-name>
        <servlet-class>com.mahe666.servlet.GetServlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>getC</servlet-name>
        <url-pattern>/getC</url-pattern>
    </servlet-mapping>

</web-app>

setAttribute方法 共享数据

setAttribute方法共享数据