1.一个web项目对应一个ServletContext，它代表当前web项目的信息
2.还可以作为最大的域对象在整个项目运行期间共享数据
package com.guo;
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 HelloServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
ServletContext servletContext = this.getServletContext();
servletContext.setAttribute("name","荣豪");
System.out.println("写成功！！！");
}
}
2.GetServlet获取信息类
package com.guo;
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 servletContext = this.getServletContext();
String attribute = (String) servletContext.getAttribute("name");
System.out.println("读取的信息："+attribute);
//响应到浏览器（处理乱码问题（配置类型和编码））
resp.setContentType("text/html");//响应类型
resp.setCharacterEncoding("UTF-8");//响应的编码格式
resp.getWriter().println(attribute);//响应信息显示页面
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
3.配置web.xml的映射
hello com.guo.HelloServlet hello /hello get com.guo.GetServlet get /get
写成功！！！ 读取的信息：荣豪
