Spring Boot 技术问题教程：Spring Security 权限控制

引言

在Spring Boot项目中，权限控制是确保应用安全性的重要环节。Spring Security作为一个功能强大且高度可定制的安全框架，能够与Spring Boot无缝集成，实现用户认证和权限管理。本文将介绍如何在Spring Boot项目中配置和使用Spring Security，并通过一个详细案例展示如何实现用户认证和授权。

Spring Security 基本配置

首先，在项目的pom.xml文件中添加Spring Security依赖：

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

然后，创建一个Spring Security配置类：

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.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.provisioning.InMemoryUserDetailsManager;

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

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

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

案例：用户认证和授权

接下来，我们通过一个简单的案例来展示用户认证和授权的实现。

1. 创建控制器

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.security.core.annotation.AuthenticationPrincipal;
import org.springframework.security.core.userdetails.UserDetails;

@RestController
public class MyController {

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

    @GetMapping("/admin")
    public String admin(@AuthenticationPrincipal UserDetails userDetails) {
        if (userDetails.getAuthorities().stream().anyMatch(grantedAuth -> grantedAuth.getAuthority().equals("ROLE_ADMIN"))) {
            return "Welcome to the admin page, " + userDetails.getUsername();
        } else {
            return "Access Denied!";
        }
    }

    @GetMapping("/login")
    public String login() {
        return "Login page (this is just a placeholder)";
    }
}