Spring Boot中是否有Filter类(用于web应用程序)的注释?也许@Filter ?

我想在我的项目中添加一个自定义过滤器。

Spring Boot参考指南中提到过 FilterRegistrationBean,但我不确定如何使用它。


当前回答

这是一个建议而不是答案,但如果你在你的web应用程序中使用Spring MVC,最好使用Spring HandlerInterceptor而不是Filter。

它可以做同样的工作,但是

可以使用ModelAndView吗 它的方法可以在请求处理之前和之后调用,或者在请求完成之后调用。 它很容易测试

1. 实现HandlerInterceptor接口,并向类中添加@Component注释

@Component
public class SecurityInterceptor implements HandlerInterceptor {

    private static Logger log = LoggerFactory.getLogger(SecurityInterceptor.class);

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        request.getSession(true);
        if(isLoggedIn(request))
            return true;

        response.getWriter().write("{\"loggedIn\":false}");
        return false;
    }

    private boolean isLoggedIn(HttpServletRequest request) {
        try {
            UserSession userSession = (UserSession) request.getSession(true).getAttribute("userSession");
            return userSession != null && userSession.isLoggedIn();
        } catch(IllegalStateException ex) {
            return false;
        }
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {

    }
}

2. 配置拦截器

@Configuration
public class WebConfig implements WebMvcConfigurer {

    private HandlerInterceptor securityInterceptor;

    @Autowired
    public void setSecurityInterceptor(HandlerInterceptor securityInterceptor) {
        this.securityInterceptor = securityInterceptor;
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(securityInterceptor).addPathPatterns("/**").excludePathPatterns("/login", "/logout");
    }

}

其他回答

此过滤器还将帮助您允许跨源访问

@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class SimpleCORSFilter implements Filter {

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {

            HttpServletResponse response = (HttpServletResponse) res;
            HttpServletRequest request = (HttpServletRequest) req;
            response.setHeader("Access-Control-Allow-Origin", "*");
            response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
            response.setHeader("Access-Control-Max-Age", "20000");
            response.setHeader("Access-Control-Allow-Headers", "x-requested-with, authorization, Content-Type, Authorization, credential, X-XSRF-TOKEN");

            if("OPTIONS".equalsIgnoreCase(request.getMethod())) {
                response.setStatus(HttpServletResponse.SC_OK);
            } else {
                chain.doFilter(req, res);
            }
    }


    public void destroy() {}

    @Override
    public void init(FilterConfig arg0) throws ServletException {
        // TODO Auto-generated method stub

    }

}

你可以在实现javax.servlet.Filter的类上使用@WebFilter javax.servlet.annotation.WebFilter:

@WebFilter(urlPatterns = "/*")
public class MyFilter implements Filter {
}

然后使用@ServletComponentScan注册。

没有特殊的注释来表示servlet筛选器。您只需声明一个Filter类型的@Bean(或FilterRegistrationBean)。在Boot自己的EndpointWebMvcAutoConfiguration中有一个例子(为所有响应添加自定义头);

如果你只声明一个过滤器,它将被应用到所有的请求。如果您还添加了一个FilterRegistrationBean,您可以另外指定要应用的单个servlet和url模式。

注意:

从Spring Boot 1.4开始,FilterRegistrationBean不再弃用,而是简单地将包从org.springframework. Boot .context. embedd.filterregistrationbean移动到org.springframework.boot.web.servlet.FilterRegistrationBean

如果您想要设置一个第三方过滤器,您可以使用FilterRegistrationBean。

例如,等价的web.xml:

<filter>
     <filter-name>SomeFilter</filter-name>
        <filter-class>com.somecompany.SomeFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>SomeFilter</filter-name>
    <url-pattern>/url/*</url-pattern>
    <init-param>
        <param-name>paramName</param-name>
        <param-value>paramValue</param-value>
    </init-param>
</filter-mapping>

这将是@Configuration文件中的两个bean:

@Bean
public FilterRegistrationBean someFilterRegistration() {

    FilterRegistrationBean registration = new FilterRegistrationBean();
    registration.setFilter(someFilter());
    registration.addUrlPatterns("/url/*");
    registration.addInitParameter("paramName", "paramValue");
    registration.setName("someFilter");
    registration.setOrder(1);
    return registration;
}

public Filter someFilter() {
    return new SomeFilter();
}

以上是用Spring Boot 1.2.3测试的。

这是一个建议而不是答案,但如果你在你的web应用程序中使用Spring MVC,最好使用Spring HandlerInterceptor而不是Filter。

它可以做同样的工作,但是

可以使用ModelAndView吗 它的方法可以在请求处理之前和之后调用,或者在请求完成之后调用。 它很容易测试

1. 实现HandlerInterceptor接口,并向类中添加@Component注释

@Component
public class SecurityInterceptor implements HandlerInterceptor {

    private static Logger log = LoggerFactory.getLogger(SecurityInterceptor.class);

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        request.getSession(true);
        if(isLoggedIn(request))
            return true;

        response.getWriter().write("{\"loggedIn\":false}");
        return false;
    }

    private boolean isLoggedIn(HttpServletRequest request) {
        try {
            UserSession userSession = (UserSession) request.getSession(true).getAttribute("userSession");
            return userSession != null && userSession.isLoggedIn();
        } catch(IllegalStateException ex) {
            return false;
        }
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {

    }
}

2. 配置拦截器

@Configuration
public class WebConfig implements WebMvcConfigurer {

    private HandlerInterceptor securityInterceptor;

    @Autowired
    public void setSecurityInterceptor(HandlerInterceptor securityInterceptor) {
        this.securityInterceptor = securityInterceptor;
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(securityInterceptor).addPathPatterns("/**").excludePathPatterns("/login", "/logout");
    }

}