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。
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
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。
其他回答
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");
}
}
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。
过滤器,顾名思义,用于对资源的请求或资源的响应执行过滤,或同时对两者执行过滤。Spring Boot提供了一些选项来在Spring Boot应用程序中注册自定义过滤器。让我们看看不同的选项。
1. 定义Spring Boot过滤器和调用顺序
实现Filter接口,在Spring Boot中创建一个新的过滤器。
@Configuration
@Order(Ordered.HIGHEST_PRECEDENCE)
public class CustomFilter implements Filter {
private static final Logger LOGGER = LoggerFactory.getLogger(CustomFilter.class);
@Override
public void init(FilterConfig filterConfig) throws ServletException {
LOGGER.info("########## Initiating Custom filter ##########");
}
@Override
public void doFilter(ServletRequest servletRequest,
ServletResponse servletResponse,
FilterChain filterChain)
throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) servletRequest;
HttpServletResponse response = (HttpServletResponse) servletResponse;
LOGGER.info("Logging Request {} : {}", request.getMethod(), request.getRequestURI());
// Call next filter in the filter chain
filterChain.doFilter(request, response);
LOGGER.info("Logging Response :{}", response.getContentType());
}
@Override
public void destroy() {
// TODO: 7/4/2018
}
}
让我们快速看一下上面代码中的一些要点
@Component注释注册的过滤器。 为了以正确的顺序触发过滤器,我们需要使用@Order注释。 @ component @Order (1) 公共类CustomFirstFilter实现了Filter { } @ component @Order (2) 公共类CustomSecondFilter实现了Filter { }
在上面的代码中,CustomFirstFilter将在CustomSecondFilter之前运行。
数字越低,优先级越高
2. URL模式
如果基于约定的映射不够灵活,我们可以使用FilterRegistrationBean对应用程序进行完全控制。在这里,不要为过滤器类使用@Component注释,而是使用FilterRegistrationBean注册过滤器。
public class CustomURLFilter implements Filter {
private static final Logger LOGGER = LoggerFactory.getLogger(CustomURLFilter.class);
@Override
public void init(FilterConfig filterConfig) throws ServletException {
LOGGER.info("########## Initiating CustomURLFilter filter ##########");
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) servletRequest;
HttpServletResponse response = (HttpServletResponse) servletResponse;
LOGGER.info("This Filter is only called when request is mapped for /customer resource");
// Call the next filter in the filter chain
filterChain.doFilter(request, response);
}
@Override
public void destroy() {
}
}
使用FilterRegistrationBean注册自定义过滤器。
@Configuration
public class AppConfig {
@Bean
public FilterRegistrationBean < CustomURLFilter > filterRegistrationBean() {
FilterRegistrationBean < CustomURLFilter > registrationBean = new FilterRegistrationBean();
CustomURLFilter customURLFilter = new CustomURLFilter();
registrationBean.setFilter(customURLFilter);
registrationBean.addUrlPatterns("/greeting/*");
registrationBean.setOrder(2); // Set precedence
return registrationBean;
}
}
对于Spring Boot在我所做的任何配置类:
@Bean
public OncePerRequestFilter myFilter() {
return new OncePerRequestFilter() {
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
AuthUser authUser = SecurityUtil.safeGet(); // applied after secutiry filters
...
filterChain.doFilter(request, response);
}
};
}
这就是全部,不需要任何注册。参见什么是OncePerRequestFilter?
过滤器主要用于日志文件中。它根据您在项目中使用的记录器而有所不同。
让我解释一下log4j2:
<Filters>
<!-- It prevents an error -->
<ThresholdFilter level="error" onMatch="DENY" onMismatch="NEUTRAL"/>
<!-- It prevents debug -->
<ThresholdFilter level="debug" onMatch="DENY" onMismatch="NEUTRAL" />
<!-- It allows all levels except debug/trace -->
<ThresholdFilter level="info" onMatch="ACCEPT" onMismatch="DENY" />
</Filters>
过滤器用于限制数据,我使用阈值过滤器进一步限制流中的数据级别。我提到了可以限制的水平。
请参见“log4j2 - Log4J Levels”的级别顺序:ALL > TRACE > DEBUG > INFO > WARN > ERROR > FATAL > OFF