function dss(userid,obj){ $.post("test?flag=2",{id:userid},function(data) if("删除成功"==data){ alert("删除成功"); $(obj).parent().parent().remove(); } }); }
filter:java中的filter 并不是一个标准的servlet ,它不能处理用户请求,也不能对客户端生成响应。 主要用于对httpservletrequest 进行预处理,也可以对httpservletresponse 进行后处理,是个典型的处理链。
优点:过滤链的好处是,执行过程中任何时候都可以打断,只要不执行chain.dofilter()就不会再执行后面的过滤器和请求的内容。而在实际使用时,就要特别注意过滤链的执行顺序问题.
web.xml配置filter:
<filter> <filter-name>firstfilter</filter-name> <filter-class>com.jkx.web.filter.firstfilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>firstfilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
编写filter:
package com.jkx.web.filter; import java.io.ioexception; import javax.servlet.filter; import javax.servlet.filterchain; import javax.servlet.filterconfig; import javax.servlet.servletexception; import javax.servlet.servletrequest; import javax.servlet.servletresponse; import javax.servlet.http.httpservletrequest; import javax.servlet.http.httpservletresponse; public class firstfilter implements filter{ public string encoding=null; //服务器正常关闭时执行 public void destroy() { system.out.println("firstfilter销毁"); } public void dofilter(servletrequest request, servletresponse response, filterchain chain) throws ioexception, servletexception { httpservletrequest req = (httpservletrequest) request; httpservletresponse resp = (httpservletresponse) response; req.setcharacterencoding(encoding); req.setattribute("fileparam", "222222"); chain.dofilter(req, resp); } //服务器启动时初始化 public void init(filterconfig filterconfig) throws servletexception { system.out.println("firstfilter初始化,被创建"); encoding = filterconfig.getinitparameter("encoding"); } }
以上就是ajax的简单应用和filter的编写方法的详细内容。
