写springboot整合security，权限从数据库查询的代码

首先，需要在pom.xml中添加相应的依赖：

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

<dependency>
  <groupId>org.springframework.security</groupId>
  <artifactId>spring-security-jwt</artifactId>
  <version>1.0.10.RELEASE</version>
</dependency>

然后，创建一个实现了UserDetailsService接口的类，用于从数据库中查询用户信息：

@Service
public class UserDetailsServiceImpl implements UserDetailsService {

    @Autowired
    private UserRepository userRepository;

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        User user = userRepository.findByUsername(username);

        if (user == null) {
            throw new UsernameNotFoundException("User not found with username: " + username);
        }

        return new org.springframework.security.core.userdetails.User(user.getUsername(), user.getPassword(),
                new ArrayList<>());
    }
}

接着，创建一个实现了WebSecurityConfigurerAdapter接口的类，用于配置Spring Security：

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private JwtAuthenticationEntryPoint jwtAuthenticationEntryPoint;

    @Autowired
    private UserDetailsServiceImpl userDetailsService;

    @Autowired
    private JwtRequestFilter jwtRequestFilter;

    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userDetailsService).passwordEncoder(passwordEncoder());
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Bean
    @Override
    public AuthenticationManager authenticationManagerBean() throws Exception {
        return super.authenticationManagerBean();
    }

    @Override
    protected void configure(HttpSecurity httpSecurity) throws Exception {
        httpSecurity.csrf().disable()
                .authorizeRequests().antMatchers("/authenticate").permitAll()
                .anyRequest().authenticated().and()
                .exceptionHandling().authenticationEntryPoint(jwtAuthenticationEntryPoint).and().sessionManagement()
                .sessionCreationPolicy(SessionCreationPolicy.STATELESS);

        httpSecurity.addFilterBefore(jwtRequestFilter, UsernamePasswordAuthenticationFilter.class);
    }
}

其中，JwtAuthenticationEntryPoint用于处理认证失败的异常，JwtRequestFilter用于从请求中获取JWT并验证其有效性。

最后，在application.properties中配置相关属性：

# JWT
jwt.secret=mySecretKey
jwt.expiration=86400000

其中，jwt.secret为JWT的密钥，jwt.expiration为JWT的有效期，单位为毫秒。

至此，整合SpringBoot和Spring Security的代码就完成了。