SERVLET（2）

SERVLET（2）

package  cn.mldn.lxh.servlet ;
import  java.io. *  ;
import  javax.servlet. *  ;
import  javax.servlet.http. *  ;

public   class  FormServlet  extends  HttpServlet
{
    private ServletConfig config = null ;
    public void init(ServletConfig config) throws ServletException 
    {
        this.config = config ;
    }
    // 表示处理get请求
    public void doGet(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
    {
        // System.out.println("** Servlet doGet处理提交参数 ") ;
        this.doPost(req,resp) ;
    }
    // 处理post请求
    public void doPost(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
    {
        String name = req.getParameter("uname") ;
        // 取得application对象
        // ServletContext app = this.getServletContext() ;
        ServletContext app = this.config.getServletContext() ;
        app.setAttribute("addr","www.MLDN.cn") ;
        // 取得一个session对象
        HttpSession session = req.getSession() ;
        session.setAttribute("sname",name) ;
        // System.out.println("** Servlet doPost处理提交参数 ") ;
        System.out.println("name = "+name) ;
        // 重定向
        resp.sendRedirect("demo.jsp") ;
    }
} ;

/**/ /*
  <servlet>
    <servlet-name>form</servlet-name>
    <servlet-class>cn.mldn.lxh.servlet.FormServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>form</servlet-name>
    <url-pattern>/formServlet</url-pattern>
  </servlet-mapping>
*/

初始化两种方法
有参数与无参数
有参数的方法优先


多个地址可以映射到同一个SERVLET
配置初始化参数

form表单

< form  action ="formServlet"  method ="post" >
用户名： < input  type ="text"  name ="uname" >
< input  type ="submit"  value ="提交" >
</ form >

下面是处理表单的servlet

package  cn.mldn.lxh.servlet ;
import  java.io. *  ;
import  javax.servlet. *  ;
import  javax.servlet.http. *  ;

public   class  InitParameterServlet  extends  HttpServlet
{
    // 初始化
    // 要取得初始化参数，必须使用以下初始化方法
    public void init(ServletConfig config) throws ServletException
    {
        // config对象中有取得初始化参数的方法：getInitParameter("参数名称")
        String ref1 = config.getInitParameter("ref1") ;
        String ref2 = config.getInitParameter("ref2") ;
        String dd = config.getInitParameter("DBDRIVER") ;

        System.out.println("REF1 => "+ref1) ;
        System.out.println("REF2 => "+ref2) ;
        System.out.println("DBDRIVER => "+dd) ;
    }

    // 表示处理get请求
    public void doGet(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
    {
        // System.out.println("** Servlet doGet处理 ") ;
    }
    // 处理post请求
    public void doPost(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
    {
        // System.out.println("** Servlet doPost处理 ") ;
    }
    // 销毁
    public void destroy()
    {
        // System.out.println("** Servlet 销毁 ") ;
    }
} ;

/**/ /*
  <servlet>
    <servlet-name>param</servlet-name>
    <servlet-class>cn.mldn.lxh.servlet.InitParameterServlet</servlet-class>
    <load-on-startup>0</load-on-startup>
    <init-param>
        <param-name>ref1</param-name>
        <param-value>MLDN</param-value>
    </init-param>
    <init-param>
        <param-name>ref2</param-name>
        <param-value>LiXingHua</param-value>
    </init-param>
    <init-param>
        <param-name>DBDRIVER</param-name>
        <param-value>oracle.jdbc.driver.OracleDriver</param-value>
    </init-param>
  </servlet>

  <servlet-mapping>
    <servlet-name>param</servlet-name>
    <url-pattern>/ipar</url-pattern>
  </servlet-mapping>
*/

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