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SpringBoot自定义Filter

SpringBoot自动添加了OrderedCharacterEncodingFilter和HiddenHttpMethodFilter，当然我们可以自定
义Filter。

自定义Filter需要两个步骤：

1. 实现Filter【javax.servlet.Filter】接口，实现Filter方法
2. 添加 @Configuration 注解，将自定义Filter加入过滤链

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【过滤打印请求URL】实例代码如下：

package xatu.zsl.Filter;

import org.apache.catalina.filters.RemoteIpFilter;import org.springframework.boot.web.servlet.FilterRegistrationBean;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;

import javax.servlet.*;import javax.servlet.http.HttpServletRequest;import java.io.IOException;

/*** Created by zsl on 2017/9/3.*/@Configurationpublic class ConfigurationFilter {@Beanpublic RemoteIpFilter remoteIpFilter() {return new RemoteIpFilter();}

@Beanpublic FilterRegistrationBean testFilterRegistration() {FilterRegistrationBean registration = new FilterRegistrationBean();registration.setFilter(new MyFilter());//添加过滤器registration.addUrlPatterns("/*");//设置过滤路径，/*所有路径registration.addInitParameter("name", "alue");//添加默认参数registration.setName("MyFilter");//设置优先级registration.setOrder(1);//设置优先级return registration;}

public class MyFilter implements Filter {@Overridepublic void destroy() {}

@Overridepublic void doFilter(ServletRequest srequest, ServletResponse sresponse, FilterChainfilterChain)

throws IOException, ServletException {HttpServletRequest request = (HttpServletRequest) srequest;//打印请求UrlSystem.out.println("this is MyFilter,url :" + request.getRequestURI());filterChain.doFilter(srequest, sresponse);}

@Overridepublic void init(FilterConfig arg0) throws ServletException {}}
}

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有人好奇public FilterRegistrationBean testFilterRegistration() 这个方法返回的FilterRegistrationBean如何在Coltroller中获取？，(●’◡’●)，我很好奇，，于是乎！搞了点事情

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在Controller中获取刚才ConfigurationFilter中【registration.addInitParameter(“name”, “alue”);//添加默认参数】这个设置的参数。

在Controller中加入如下代码就能获取（刚才【testFilterRegistration()】方法加了注解@Bean，所以Spring容器中会有一个实例， @Autowired就理所应当的注入进来了。）

    @AutowiredFilterRegistrationBean registration;

@GetMapping("/getname")public Map<String, String> getName() {Map<String, String> initParameters = registration.getInitParameters();return initParameters;}