获取容器的附加信息

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;
import java.io.PrintWriter;
public class GetBaseInfoServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ServletContext servletContext = this.getServletContext();
        //获取容器信息
        String serverInfo = servletContext.getServerInfo();
        //获取容器支持servlet的主版本号
        int majorVersion  = servletContext.getMajorVersion();
        //获取容器支持的servlet的副版本好
        int minorVersion = servletContext.getMinorVersion();
        //设置响应编码
        resp.setContentType("text/plain;charset=utf-8");
        PrintWriter printWriter = resp.getWriter();
        printWriter.println(serverInfo);
        printWriter.println(majorVersion+minorVersion);
        printWriter.flush();
        printWriter.close();
    }
}