HttpSecurity कॉन्फ़िगरेशन की गहन जानकारी

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.web.SecurityFilterChain;

// This snippet shows the core authorizeHttpRequests() part.
// It assumes the surrounding Spring Boot application and 
// SecurityConfig class from the previous scene.

@Configuration
@EnableWebSecurity
class SecurityConfigSnippet {

    @Bean
    public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
        http
            .authorizeHttpRequests(auth -> auth
                // Your specific rules go here!
                // Example: .requestMatchers("/public/**").permitAll()
                // Example: .anyRequest().authenticated()
            )
            .formLogin(form -> form.permitAll())
            .logout(logout -> logout.permitAll());
        return http.build();
    }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.provisioning.InMemoryUserDetailsManager;
import org.springframework.security.web.SecurityFilterChain;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class PublicPrivateApp {

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

    @GetMapping("/public")
    public String publicContent() {
        return "This is public content!";
    }

    @GetMapping("/private")
    public String privateContent() {
        return "This is private content!";
    }

    @GetMapping("/secret")
    public String secretContent() {
        return "Top secret! No one allowed here.";
    }
}

@Configuration
@EnableWebSecurity
class SecurityConfigPublicPrivate {

    @Bean
    public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
        http
            .authorizeHttpRequests(auth -> auth
                .requestMatchers("/public/**").permitAll() // Anyone can access
                .requestMatchers("/secret/**").denyAll()   // No one can access
                .anyRequest().authenticated()              // All other requests need login
            )
            .formLogin(form -> form.permitAll())
            .logout(logout -> logout.permitAll());
        return http.build();
    }

    @Bean
    public UserDetailsService userDetailsService() {
        UserDetails user = User.withDefaultPasswordEncoder()
            .username("user")
            .password("password")
            .roles("USER")
            .build();
        return new InMemoryUserDetailsManager(user);
    }
}

// Inside your SecurityFilterChain configuration:
http
    .authorizeHttpRequests(auth -> auth
        .requestMatchers("/login", "/register").permitAll() // Public paths
        .requestMatchers("/dashboard/**").authenticated() // Needs login
        .anyRequest().denyAll() // Deny everything else by default
    )
    // ... other http configurations (formLogin, logout) ...

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.provisioning.InMemoryUserDetailsManager;
import org.springframework.security.web.SecurityFilterChain;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class RoleBasedApp {

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

    @GetMapping("/home")
    public String home() { return "Welcome!"; }

    @GetMapping("/user-dashboard")
    public String userDashboard() { return "User Dashboard!"; }

    @GetMapping("/admin-panel")
    public String adminPanel() { return "Admin Panel!"; }
}

@Configuration
@EnableWebSecurity
class SecurityConfigRoles {

    @Bean
    public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
        http
            .authorizeHttpRequests(auth -> auth
                .requestMatchers("/home").permitAll()
                .requestMatchers("/user-dashboard").hasRole("USER") // Only users with ROLE_USER
                .requestMatchers("/admin-panel").hasRole("ADMIN")   // Only users with ROLE_ADMIN
                .anyRequest().authenticated() // All others need login
            )
            .formLogin(form -> form.permitAll())
            .logout(logout -> logout.permitAll());
        return http.build();
    }

    @Bean
    public UserDetailsService userDetailsService() {
        UserDetails user = User.withDefaultPasswordEncoder()
            .username("user")
            .password("password")
            .roles("USER")
            .build();
        UserDetails admin = User.withDefaultPasswordEncoder()
            .username("admin")
            .password("admin")
            .roles("ADMIN")
            .build();
        return new InMemoryUserDetailsManager(user, admin);
    }
}

// Incorrect order example (the second rule is unreachable):
// auth
//   .requestMatchers("/admin/**").authenticated()
//   .requestMatchers("/admin/public").permitAll() 

// Correct order example:
// auth
//   .requestMatchers("/admin/public").permitAll()
//   .requestMatchers("/admin/**").hasRole("ADMIN")
//   .anyRequest().authenticated()

// Inside your SecurityFilterChain configuration:
http
    .authorizeHttpRequests(auth -> auth
        .anyRequest().authenticated()
    )
    .formLogin(form -> form
        .loginPage("/custom-login")      // Specify custom login page URL
        .loginProcessingUrl("/authenticate") // URL to submit login data
        .defaultSuccessUrl("/dashboard", true) // Redirect after success
        .failureUrl("/custom-login?error")  // Redirect on failure
        .permitAll() // Allow access to login page and its processing
    )
    .logout(logout -> logout.permitAll());

// Inside your SecurityFilterChain configuration:
http
    // ... authorization rules ...
    .csrf(csrf -> csrf.disable()) // ONLY disable if you know what you're doing!
                                  // Common for stateless REST APIs.
    // ... formLogin, logout ...
;