The error “Caused by: java.lang.IllegalArgumentException: AuthenticationManager must be specified” typically occurs in a Spring Security configuration when the authentication manager is not properly defined or missing. The authentication manager is a crucial component that handles user authentication and authorization.
To resolve this error, you need to ensure that the authentication manager is correctly configured in your Spring Security configuration file. Here is an example of how you can define and specify the authentication manager:
<!-- In your Spring Security configuration file -->
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:security="http://www.springframework.org/schema/security"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security.xsd">
<security:authentication-manager>
<security:authentication-provider>
<security:user-service>
<security:user name="admin" password="password" authorities="ROLE_USER"/>
</security:user-service>
</security:authentication-provider>
</security:authentication-manager>
</beans>
In the above example, we configure an in-memory authentication provider using the <security:authentication-provider> element. Inside the authentication provider, we define a user with the name “admin”, password “password”, and assigned the “ROLE_USER” authority. This is a simplified example, and in a practical scenario, you would typically configure authentication against a database or other supported authentication providers.
Make sure to adapt the authentication manager configuration to your specific requirements. Once you have defined the authentication manager correctly, the error should no longer occur.