How can security authentication and authorization be implemented in Spring Boot?

In Spring Boot, security authentication and authorization can be achieved using Spring Security. Spring Security is a robust and highly customizable framework that can assist in easily implementing various security features such as user authentication, authorization, password encryption, and session management.

Here is a general overview of the steps to implement authentication and authorization security using Spring Security in Spring Boot.

1. Include the Spring Security dependency.

Add the dependency for Spring Security in the pom.xml file.

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

1. Create a configuration class that extends WebSecurityConfigurerAdapter.

@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/admin/**").hasRole("ADMIN")
                .antMatchers("/user/**").hasRole("USER")
                .anyRequest().authenticated()
                .and()
            .formLogin()
                .loginPage("/login")
                .defaultSuccessUrl("/home")
                .permitAll()
                .and()
            .logout()
                .permitAll();
    }

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth
            .inMemoryAuthentication()
                .withUser("admin").password("{noop}admin123").roles("ADMIN")
                .and()
                .withUser("user").password("{noop}user123").roles("USER");
    }
}

1. Basic security rules have been configured in the above configuration class, including:

1. Only users with the ADMIN role can access the /admin/** path.
2. Access to the /user/** path requires the USER role.
3. Access to other paths requires authentication.
4. The setup includes a login page, a redirect page after successful login, and a logout page.

1. When launching the application and accessing a page that requires authentication, you will be redirected to the login page. After entering the correct username and password, you will be redirected to the corresponding page.

In summary, using Spring Security makes it easy to implement security authentication and authorization functions with just simple configurations. Additionally, Spring Security offers advanced features and customization options for further configuration and expansion based on specific needs.