springboot如何配置Filter過濾器

更新時間：2023年12月11日 14:25:02 作者：小布的世界

這篇文章主要介紹了springboot如何配置Filter過濾器問題,具有很好的參考價值,希望對大家有所幫助,如有錯誤或未考慮完全的地方,望不吝賜教

springboot配置Filter過濾器

Filter 過濾器是web開發(fā)中很重要的一個組件，下面以一個session登陸的例子介紹下spring boot中如何使用Filter

首先要準(zhǔn)備一個實(shí)現(xiàn)了Filter的接口的類

SessionFilter：

import org.slf4j.LoggerFactory;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Created by mazhenhua on 2016/12/27.
 *
 * 過濾器
 */
public class SessionFilter implements Filter {
    private static final org.slf4j.Logger logger = LoggerFactory.getLogger(SessionFilter.class);


    /**
     * 封裝，不需要過濾的list列表
     */
    protected static List<Pattern> patterns = new ArrayList<Pattern>();

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

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;
        HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
        logger.info("aaaaaaaaaa");
        String url = httpRequest.getRequestURI().substring(httpRequest.getContextPath().length());
        if (url.startsWith("/") && url.length() > 1) {
            url = url.substring(1);
        }

        if (isInclude(url)){
            chain.doFilter(httpRequest, httpResponse);
            return;
        } else {
            HttpSession session = httpRequest.getSession();
            if (session.getAttribute("") != null){
                // session存在
                chain.doFilter(httpRequest, httpResponse);
                return;
            } else {
                // session不存在 準(zhǔn)備跳轉(zhuǎn)失敗
                /* RequestDispatcher dispatcher = request.getRequestDispatcher(path);
                    dispatcher.forward(request, response);*/
                chain.doFilter(httpRequest, httpResponse);
                return;
            }
        }


    }

    @Override
    public void destroy() {

    }


    /**
     * 是否需要過濾
     * @param url
     * @return
     */
    private boolean isInclude(String url) {
        for (Pattern pattern : patterns) {
            Matcher matcher = pattern.matcher(url);
            if (matcher.matches()) {
                return true;
            }
        }
        return false;
    }

}

實(shí)際開發(fā)中往往有很多請求要直接請求進(jìn)來

不需要鑒權(quán)登陸的，所以代碼中過濾掉這種請求的代碼，裝進(jìn)list就好了。

    /**
     * 配置過濾器
     * @return
     */
    @Bean
    public FilterRegistrationBean someFilterRegistration() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(sessionFilter());
        registration.addUrlPatterns("/*");
        registration.addInitParameter("paramName", "paramValue");
        registration.setName("sessionFilter");
        return registration;
    }

    /**
     * 創(chuàng)建一個bean
     * @return
     */
    @Bean(name = "sessionFilter")
    public Filter sessionFilter() {
        return new SessionFilter();
    }

經(jīng)過上面這倆步的配置，過濾器基本上就可以了。

配置多個filter，并指定順序，請參考： spring boot filter 配置多個時，執(zhí)行順序