java / j2ee / jee filter学习笔记(一)

取得web.xml里面的参数:

web.xml的部分代码

 

<filter>
      <filter-name>t</filter-name>
    <filter-class>test.t</filter-class>
    <init-param>
    <param-name>kk</param-name>
    <param-value>kk-value</param-value>
    </init-param>
  </filter>

  <filter-mapping>
    <filter-name>t</filter-name>
    <url-pattern>/servlet/t</url-pattern>
  </filter-mapping>

filter的代码

 

public void init(FilterConfig filterConfig) throws ServletException ...{
        // TODO Auto-generated method stub
        System.out.println("12lsx");
        Map<String,String> params = new HashMap<String,String>();
        for (Enumeration e = filterConfig.getInitParameterNames(); e.hasMoreElements(); ) ...{
            String name = (String) e.nextElement();
            System.out.println("name="+name);
            String value = filterConfig.getInitParameter(name);
            System.out.println("value="+value);
            params.put(name, value);
        }
    }