2022-5-10作业

1 分别单独给某个Servlet 以及 ServletContext 设置配置信息并获取，截图展示结果

Servlet

public class zyServlet extends HttpServlet {
    @Override
    public void init() throws ServletException {
        System.out.println("初始化");
    }


    @Override
    public ServletConfig getServletConfig() {
        ServletConfig servletConfig = super.getServletConfig();
        System.out.println("zyServlet的配置对象:" + servletConfig);
        return servletConfig;
    }

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("响应客户端请求, hhhh" );
        ServletConfig servletConfig = this.getServletConfig();
        System.out.println("zyServlet的相关信息" + servletConfig);

    }

    @Override
    public void destroy() {
        System.out.println("zyServlet的销毁方法");
    }

}

web.xml文件代码

        zyServlet
        com.qiku.web.zyServlet
    
    
        zyServlet
        /zyServlet
    

运行结果：

 

ServletContext

@WebServlet(name = "zyServletContext" , urlPatterns = "/zycontext")
public class zyServletContext extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ServletContext zycontext = getServletConfig().getServletContext();
        ServletContext servletContext = getServletConfig().getServletContext();
        System.out.println(servletContext);
        Enumeration initParameterNames = zycontext.getInitParameterNames();
        while(initParameterNames.hasMoreElements()){
            String s = initParameterNames.nextElement();
            System.out.println(s + "对应的值" + zycontext.getInitParameter(s));

        }


        String contextPath = zycontext.getContextPath();
        System.out.println("相对路径:" + contextPath);

        String realPath = zycontext.getRealPath("/");
        System.out.println("绝对路径:" +realPath);

        zycontext.setAttribute("param2","values2");
        Object param2 = zycontext.getAttribute("param2");
        System.out.println("根据属性名获得属性值:" + param2);

        zycontext.removeAttribute("param2");
        param2 = zycontext.getAttribute("param2");
        System.out.println("根据属性名删除属性值:" + param2);
    }

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

        System.out.println("do get");
        doPost(req,resp);
    }
}

xml文件 ：

 
        username
        root
    
    
        password
        123456789
    

 结果：