setUnauthorizedUrl("/403")不起作用

SpringBoot中集成Shiro的时候， 配置setUnauthorizedUrl("/403")了，但是不起作用，只会在控制台打印UnauthorizedException异常信息：

原因：
Shiro源码中是这样做的：

    private void applyUnauthorizedUrlIfNecessary(Filter filter) {
        String unauthorizedUrl = this.getUnauthorizedUrl();
        if(StringUtils.hasText(unauthorizedUrl) && filter instanceof AuthorizationFilter) {
            AuthorizationFilter authzFilter = (AuthorizationFilter)filter;
            String existingUnauthorizedUrl = authzFilter.getUnauthorizedUrl();
            if(existingUnauthorizedUrl == null) {
                authzFilter.setUnauthorizedUrl(unauthorizedUrl);
            }
        }

    }

只有perms，roles，ssl，rest，port才是属于AuthorizationFilter，而anon，authcBasic，authc，user是AuthenticationFilter，所以unauthorizedUrl设置后不起作用，只会在控制台打印异常信息。

接下来，我们需要做一些配置，自己来处理UnauthorizedException异常：

1.第一种方式

@Configuration
public class ExceptionConf {

    @Bean
    public SimpleMappingExceptionResolver resolver() {
        SimpleMappingExceptionResolver resolver = new SimpleMappingExceptionResolver();
        Properties properties = new Properties();
        properties.setProperty("org.apache.shiro.authz.UnauthorizedException", "/403");
        resolver.setExceptionMappings(properties);
        return resolver;
    }
}

当然，还有其他的方法可以自己处理。
比如：

2.用spring mvc的统一异常处理类HandlerExceptionResolver

定义一个类继承HandlerExceptionResolver，然后判断UnauthorizedException异常即可。

public class MyExceptionResolver implements HandlerExceptionResolver {

    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
        if (e instanceof UnauthorizedException) {
            ModelAndView mv = new ModelAndView("/403");
            return mv;
        }
        return null;
    }
}

然后，在启动类中注册该bean

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

    // 注册统一异常处理bean
    @Bean
    public MyExceptionResolver myExceptionResolver() {
        return new MyExceptionResolver();
    }
}