Spring Boot：accessDeniedHandler 不起作用

使用Spring Boot开发Web应用程序时，有时候我们需要对用户的访问进行权限控制。在这种情况下，我们可以使用Spring Security来实现访问控制。Spring Security是一个功能强大且灵活的框架，可以帮助我们轻松地实现各种身份验证和授权方案。

xml
    org.springframework.boot
    spring-boot-starter-security

java
@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
                .antMatchers("/admin/**").hasRole("ADMIN")
                .anyRequest().authenticated()
                .and()
                .formLogin()
                .and()
                .exceptionHandling()
                .accessDeniedHandler(accessDeniedHandler());
    }
    @Bean
    public AccessDeniedHandler accessDeniedHandler() {
        return new CustomAccessDeniedHandler();
    }
}

java
public class CustomAccessDeniedHandler implements AccessDeniedHandler {
    @Override
    public void handle(HttpServletRequest request, HttpServletResponse response, AccessDeniedException accessDeniedException) throws IOException, ServletException {
        response.sendRedirect("/access-denied");
    }
}

java
@RestController
public class HomeController {
    @GetMapping("/")
    public String home() {
        return "Welcome to the home page!";
    }
    @GetMapping("/admin")
    public String admin() {
        return "Welcome to the admin page!";
    }
    @GetMapping("/access-denied")
    public String accessDenied() {
        return "Access Denied!";
    }
}