“No Bean Named ‘springSecurityFilterChain’ is Defined” Error in Spring Security

Introduction:
When working with Spring Security, encountering the error “No Bean Named ‘springSecurityFilterChain’ is Defined” can be frustrating. This error typically occurs when Spring Security cannot find the required springSecurityFilterChain bean in the application context. Fortunately, resolving this issue is usually straightforward. Let’s explore some common causes and solutions.

1. Missing Security Configuration:
Ensure that you have properly configured Spring Security in your application. This often involves creating a class that extends WebSecurityConfigurerAdapter and overrides the configure(HttpSecurity http) method.

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/public/**").permitAll()
                .anyRequest().authenticated()
            .and()
            .formLogin()
                .loginPage("/login")
                .permitAll()
            .and()
            .logout()
                .logoutSuccessUrl("/login?logout")
                .permitAll();
    }
}

2. Component Scanning Issue:
Ensure that your security configuration class is being picked up during component scanning. If it’s in a different package, make sure it’s included in your component scan configuration.

@SpringBootApplication
@ComponentScan(basePackages = {"com.example"})
public class YourApplication {
    public static void main(String[] args) {
        SpringApplication.run(YourApplication.class, args);
    }
}

3. Incorrect Bean Name:
If you’ve explicitly defined the springSecurityFilterChain bean, ensure that the bean name matches exactly.

@Bean(name = AbstractSecurityWebApplicationInitializer.DEFAULT_FILTER_NAME)
public Filter springSecurityFilterChain() {
    // Your filter configuration here
    return new DelegatingFilterProxy();
}

4. Multiple Security Configurations:
If you have multiple security configurations, ensure that they are properly configured and that there are no conflicts between them.

5. Check Dependencies:
Ensure that you have all the necessary Spring Security dependencies in your pom.xml (if using Maven) or build.gradle (if using Gradle) file.

Conclusion:
By following these steps and reviewing your Spring Security configuration, you should be able to resolve the “No Bean Named ‘springSecurityFilterChain’ is Defined” error. Remember to check your security configuration, component scanning, bean names, and dependencies. Once resolved, your Spring Security setup should function smoothly without encountering this error.