springboot中配置过滤器以及可能出现的问题

　　在springboot添加过滤器有两种方式：

　　　　1、通过创建FilterRegistrationBean的方式（建议使用此种方式，统一管理，且通过注解的方式若不是本地调试，如果在filter中需要增加cookie可能会存在写不进前端情况）

　　　　2、通过注解@WebFilter的方式

　　通过创建FilterRegistrationBean的方式创建多个filter以及设置执行顺序：

　　　　　1、创建两个实现Filter接口的类TestFilter1 、TestFilter2

package com.aoxun.core.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;

public class TestFilter1 implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {}

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        chain.doFilter(request, response);
    }

    @Override
    public void destroy() {}

}

package com.aoxun.core.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;

public class TestFilter2 implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {}

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        chain.doFilter(request, response);
    }

    @Override
    public void destroy() {}

}

　　　　2、创建配置类

　　　　　　有多个filter就创建多个FilterRegistrationBean ，若需注明filter的执行顺序，可通过registration.setOrder(FilterRegistrationBean.LOWEST_PRECEDENCE - 1)配置，值越大，执行顺序越靠后

package com.aoxun.config.web;

import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.aoxun.core.filter.TestFilter1;
import com.aoxun.core.filter.TestFilter2;

/**
 * filter配置
 * @author zcj
 *
 */
@Configuration
public class FilterConfig2 {

    @Bean
    public FilterRegistrationBean companyUrlFilterRegister() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        //注入过滤器
        registration.setFilter(new TestFilter1());
        //拦截规则
        registration.addUrlPatterns("/*");
        //过滤器名称
        registration.setName("testFilter1");
        //过滤器顺序
        registration.setOrder(FilterRegistrationBean.LOWEST_PRECEDENCE);
        return registration;
    }
    
    @Bean
    public FilterRegistrationBean outLinkSecurityFilterRegister() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        //注入过滤器
        registration.setFilter(new TestFilter2());
        //拦截规则
        registration.addUrlPatterns("/*");
        //过滤器名称
        registration.setName("testFilter2");
        //过滤器顺序
        registration.setOrder(FilterRegistrationBean.LOWEST_PRECEDENCE - 1);
        return registration;
    }
    
}

　　　　

　　　　通过注解@WebFilter的方式

　　　　　1、在启动类上增加@ServletComponentScan注解，自动扫描带有过滤器注解的包

　　　　　　  2、在类上使用@WebFilter和@Order组合实现

　　　　

package com.aoxun.core.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.annotation.WebFilter;

import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.core.annotation.Order;

@WebFilter(filterName="testFilter1",urlPatterns= {"/*"})
@Order(FilterRegistrationBean.LOWEST_PRECEDENCE)
public class TestFilter1 implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        // TODO Auto-generated method stub

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {

        chain.doFilter(request, response);

    }

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

    }

}