Springboot实现filter拦截token验证和跨域

背景

web验证授权合法的一般分为下面几种

• 使用session作为验证合法用户访问的验证方式
• 使用自己实现的token
• 使用OCA标准

在使用API接口授权验证时，token是自定义的方式实现起来不需要引入其他东西，关键是简单实用。

合法登陆后一般使用用户UID+盐值+时间戳使用多层对称加密生成token并放入分布式缓存中设置固定的过期时间长（和session的方式有些相同），这样当用户访问时使用token可以解密获取它的UID并据此验证其是否是合法的用户。

springboot中实现filter

• 一种是注解filter
• 一种是显示的硬编码注册filter

先有filter

import javax.servlet.annotation.WebFilter;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import springfox.documentation.spring.web.json.Json;

import com.alibaba.fastjson.JSON;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;

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;

/***************
 * token验证拦截
 * @author bamboo zjcjava@163.com
 * @time 2017-08-01
 */
@Component
//@WebFilter(urlPatterns = { "/api/v/*" }, filterName = "tokenAuthorFilter")
public class TokenAuthorFilter implements Filter {

    private static Logger logger = LoggerFactory
            .getLogger(TokenAuthorFilter.class);

    @Override
    public void destroy() {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse rep = (HttpServletResponse) response;

        //设置允许跨域的配置
        // 这里填写你允许进行跨域的主机ip（正式上线时可以动态配置具体允许的域名和IP）
        rep.setHeader("Access-Control-Allow-Origin", "*");
        // 允许的访问方法
        rep.setHeader("Access-Control-Allow-Methods","POST, GET, PUT, OPTIONS, DELETE, PATCH");
        // Access-Control-Max-Age 用于 CORS 相关配置的缓存
        rep.setHeader("Access-Control-Max-Age", "3600");
        rep.setHeader("Access-Control-Allow-Headers","token,Origin, X-Requested-With, Content-Type, Accept");

        response.setCharacterEncoding("UTF-8");
        response.setContentType("application/json; charset=utf-8");
        String token = req.getHeader("token");//header方式
        ResultInfo resultInfo = new ResultInfo();
        boolean isFilter = false;

        String method = ((HttpServletRequest) request).getMethod();
        if (method.equals("OPTIONS")) {
            rep.setStatus(HttpServletResponse.SC_OK);
        }else{

            if (null == token || token.isEmpty()) {
                resultInfo.setCode(Constant.UN_AUTHORIZED);
                resultInfo.setMsg("用户授权认证没有通过!客户端请求参数中无token信息");
            } else {
                if (TokenUtil.volidateToken(token)) {
                    resultInfo.setCode(Constant.SUCCESS);
                    resultInfo.setMsg("用户授权认证通过!");
                    isFilter = true;
                } else {
                    resultInfo.setCode(Constant.UN_AUTHORIZED);
                    resultInfo.setMsg("用户授权认证没有通过!客户端请求参数token信息无效");
                }
            }
            if (resultInfo.getCode() == Constant.UN_AUTHORIZED) {// 验证失败
                PrintWriter writer = null;
                OutputStreamWriter osw = null;
                try {
                    osw = new OutputStreamWriter(response.getOutputStream(),
                            "UTF-8");
                    writer = new PrintWriter(osw, true);
                    String jsonStr = JSON.toJSONString(resultInfo);
                    writer.write(jsonStr);
                    writer.flush();
                    writer.close();
                    osw.close();
                } catch (UnsupportedEncodingException e) {
                    logger.error("过滤器返回信息失败:" + e.getMessage(), e);
                } catch (IOException e) {
                    logger.error("过滤器返回信息失败:" + e.getMessage(), e);
                } finally {
                    if (null != writer) {
                        writer.close();
                    }
                    if (null != osw) {
                        osw.close();
                    }
                }
                return;
            }

            if (isFilter) {
            logger.info("token filter过滤ok!");
            chain.doFilter(request, response);
            }
        }

    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {

    }

}

注解配置filter

加上如下配置则启动时会根据注解加载此filter 
@WebFilter(urlPatterns = { “/api/*” }, filterName = “tokenAuthorFilter”)

硬编码注册filter

在application.java中加入如下代码

 //注册filter
    @Bean
    public FilterRegistrationBean  filterRegistrationBean() {
        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        TokenAuthorFilter tokenAuthorFilter = new TokenAuthorFilter();
        registrationBean.setFilter(tokenAuthorFilter);
        List<String> urlPatterns = new ArrayList<String>();
        urlPatterns.add("/api/*");
        registrationBean.setUrlPatterns(urlPatterns);
        return registrationBean;
    }  

以上两种方式都可以实现filter

跨域说明

springboot可以设置全局跨域，但是对于filter中的拦截地址并不其中作用，因此需要在dofilter中再次设置一次

区局设置跨域方式如下

方式1.在application.java中加入如下代码

//跨域设置
    private CorsConfiguration buildConfig() {
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.addAllowedOrigin("*");
        corsConfiguration.addAllowedHeader("*");
        corsConfiguration.addAllowedMethod("*");  

        return corsConfiguration;
    }  

    /**
     * 跨域过滤器
     * @return
     */
    @Bean
    public CorsFilter corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", buildConfig()); // 4
        return new CorsFilter(source);
    }  

方式2.配置注解

必须集成WebMvcConfigurerAdapter类

/**********
 * 跨域 CORS:使用 方法3
 * 方法:
    1服务端设置Respone Header头中Access-Control-Allow-Origin
    2配合前台使用jsonp
    3继承WebMvcConfigurerAdapter 添加配置类
    http://blog.csdn.net/hanghangde/article/details/53946366
 * @author xialeme
 *
 */
@Configuration
public class CorsConfig extends WebMvcConfigurerAdapter{  

   /* @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("*")
                .allowCredentials(true)
                .allowedMethods("GET", "POST", "DELETE", "PUT")
                .maxAge(3600);
    }  */

    private CorsConfiguration buildConfig() {
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.addAllowedOrigin("*"); //
        corsConfiguration.addAllowedHeader("*"); //
        corsConfiguration.addAllowedMethod("*"); //
        return corsConfiguration;
    }

    @Bean
    public CorsFilter corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", buildConfig()); //
        return new CorsFilter(source);
    }

}