struts2拦截器与过滤器

1.拦截器只拦截请求
  过滤器过滤request和response
2.用户登陆拦截器：

/**
 * 用户登陆的拦截器
 * 
 * @author xxx
 * @date 2014-10-22
 * @time 下午3:24:33
 * @version 1.0
 */
@SuppressWarnings("serial")
public class LoginInterceptor extends AbstractInterceptor {
	private static Logger logger = Logger.getLogger(LoginInterceptor.class);

	@Override
	public String intercept(ActionInvocation invocation) throws Exception
	{
//		String className = invocation.getAction().getClass().getName();
//	    String action = className.substring(className.lastIndexOf(".")+1,className.length());
//	    String actionName = invocation.getProxy().getActionName();
//	    logger.info("className="+className+";action="+action+";actionName="+actionName);
		String result;
		HttpServletRequest request = ServletActionContext.getRequest();
		HttpServletResponse response = ServletActionContext.getResponse();
		ActionContext ctx = invocation.getInvocationContext();// 取得请求相关的ActionContext实例
		Map<String, Object> session = ctx.getSession();
		Operator user = (Operator) session.get(WebConstant.OPERATOR);
		if (null == user)//session超时
		{
			String type = request.getHeader("X-Requested-With");
			if ("XMLHttpRequest".equalsIgnoreCase(type)|| request.getParameter("ajax") != null)//ajax提交的请求
			{
				response.setHeader("sessionstatus", "timeout");
				logger.warn("Ajax提交，请求超时，请重新登录");
				result = null;
			} else//其他方式提交的请求
			{
				logger.warn("请求超时，请重新登录");
				result = Action.LOGIN;
			}
		} else
		{
			SessionUser.setOperator(user);
			result = invocation.invoke();
		}
		return result;
	}

}

在struts.xml配置：

<package name="default" extends="struts-default"> 
	<!-- 定义一个拦截器  拦截用户必须先登录-->  
	<interceptors>  
		<interceptor name="authority" class="xxxx.filter.LoginInterceptor" />  //自定义的拦截器
		<!-- 拦截器栈 --> 包含自定义拦截器和默认拦截器
	   <interceptor-stack name="mydefault">  
			<interceptor-ref name="defaultStack" />  
			<interceptor-ref name="authority" />  
		</interceptor-stack>  
	</interceptors>  
	<!-- 定义全局Result -->  
	<global-results>  
	   <!-- 当返回login视图名时，转入/login.jsp页面 -->  
	   <!--<result name="login" >user/login.action</result>  --> 
		<result name="login" >/jsp/login.jsp</result>
		<result name="input" >/jsp/login.jsp</result>
	</global-results>  
</package>	

使用：action类上annotation
@InterceptorRefs({
@InterceptorRef("mydefault")
})
3.编码格式过滤器

/**
 * 编码过滤器
 * @author xxx
 * @date 2014-10-22
 * @time 下午3:24:33
 * @version 1.0
 */
public class EncodeFilter implements Filter  {
	private FilterConfig config = null;  
    private String encoding = null;  
	
    @Override
	public void destroy() {
		config = null;  
        encoding = null; 
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		 if (encoding == null) {  
	            encoding = config.getInitParameter("encoding");  
	           }  
	           request.setCharacterEncoding(encoding);  
	           response.setCharacterEncoding(encoding); 
//	           response.setContentType("text/html;charset="+encoding );
	           chain.doFilter(request, response);  
	}

	@Override
	public void init(FilterConfig config) throws ServletException {
		this.config = config;
	}


}

web.xml配置过滤规则

<!-- 编码格式过滤 -->
<filter>   
	<filter-name>encoding</filter-name>   
	<filter-class>xxx.filter.EncodeFilter  </filter-class>   
	<init-param>   
		<param-name>encoding</param-name>   
		<param-value>UTF-8</param-value>   
	</init-param>   
</filter>    
<filter-mapping>  
	   <filter-name>encoding</filter-name>  
	   <url-pattern>/*</url-pattern>  
</filter-mapping>