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Web开发需要常见的问题

1、sendRedirec()方法执行后,是会直接跳转到目标页面还是执行完其后的语句再跳转到目标页面???

  该方法在执行完其后面的语句才会跳转到目标页面,比如:

  public void doGet(HttpServletRequest req,HttpServletResponse resp)throws ServletException,IOException{

    req.setCharacterEncoding("utf-8");

    String name = req.getParameter("userName");

    if(name==null || name.equals(" ")){

      resp.sendRedirec("input.jsp");

      return;  //调用return语句,结束doGet方法,避免后面的语句执行

    }

    PrintWriter out = resp.getWriter();

    out.println("hello");

  }

 2 在web.xml配置文件中有如下配置,Servlet容器会创建几个HelloServlet实例???

<servlet>

  <servlet-name>hello_zh</servlet-name>

  <servlet-class>com.hzw.HelloServlet</servlet-class>

  <init-param>

    <param-name>language</param-name>

    <param-value>中文</param-value>

    <param-name>mesage</param-name>

    <param-value>欢迎</param-value>

  </init-param>

<servlet/>

<servlet-mapping>

  <servlet-name>hello_zh</servlet-name>

  <url-pattern>/zh/hello</url-pattern>

</servlet-mapping>

 

<servlet>

  <servlet-name>hello_en</servlet-name>

  <servlet-class>com.hzw.HelloServlet</servlet-class>

  <init-param>

    <param-name>language</param-name>

    <param-value>English</param-value>

    <param-name>mesage</param-name>

    <param-value>welcome</param-value>

  </init-param>

<servlet/>

<servlet-mapping>

  <servlet-name>hello_en</servlet-name>

  <url-pattern>/en/hello</url-pattern>

</servlet-mapping>

 Servlet容器是根据web.xml配置文件中Servlet的数量来创建Servlet实例,而不管Servlet类是不是同一个

 

Web开发需要常见的问题