Java中bcrypt算法实现密码加密的方法步骤

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

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userDetailsService()).passwordEncoder(passwordEncoder());
    }
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
            .antMatchers("/admin/**").hasRole("ADMIN")
            .antMatchers("/user/**").hasAnyRole("USER", "ADMIN")
            .anyRequest().authenticated()
            .and()
            .formLogin().permitAll()
            .and()
            .logout().permitAll();
    }
    @Bean
    public BCryptPasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }
    @Bean
    public UserDetailsService userDetailsService() {
        // 返回自定义的UserDetailsService实现类，用于从数据库中获取用户信息
        return new UserDetailsServiceImpl();
    }
}

@Service
public class UserDetailsServiceImpl implements UserDetailsService {
    @Autowired
    private UserMapper userMapper;
    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        User user = userMapper.findByUsername(username);
        if (user == null) {
            throw new UsernameNotFoundException("User not found");
        }
        return new org.springframework.security.core.userdetails.User(user.getUsername(), user.getPassword(), getAuthorities(user));
    }
    private Collection<GrantedAuthority> getAuthorities(User user) {
        List<String> roles = user.getRoles();
        List<GrantedAuthority> authorities = new ArrayList<>();
        for (String role : roles) {
            authorities.add(new SimpleGrantedAuthority(role));
        }
        return authorities;
    }
}

@Autowired
private BCryptPasswordEncoder passwordEncoder;
public void registerUser(User user) {
    // 加密密码
    String encryptedPassword = passwordEncoder.encode(user.getPassword());
    user.setPassword(encryptedPassword);
    // 保存到数据库
    userMapper.save(user);
}