filter实例

web.xml:

 

   

                 <filter>
	    <filter-name>FilterTest</filter-name>
	    <filter-class>org.util.filterTest</filter-class>
	</filter>
                <filter-mapping>
	     <filter-name>FilterTest</filter-name>
	      <url-pattern>/h1.jsp</url-pattern>  //指定过滤器过滤的页面，如果写“/”则是所有请求
	</filter-mapping>

 

filterTest.java:

public class filterTest implements Filter{

	public void destroy() {
		// TODO Auto-generated method stub
		
	}

	public void doFilter(ServletRequest arg0, ServletResponse arg1,
			FilterChain arg2) throws IOException, ServletException {
		// TODO Auto-generated method stub
		System.out.println("filter start");
	    
	}

	public void init(FilterConfig arg0) throws ServletException {
		// TODO Auto-generated method stub
		
	}

}

 

 

在游览器中输入http://localhost:8080/Test/h1.jsp则会打印filter start

输入http://localhost:8080/Test/h2.jsp则不会打印