spring security国际化及UserCache的配置和使用

1. Spring Security国际化配置：

要实现Spring Security的国际化，需要进行以下配置：

（1）在Spring Security的配置文件中增加MessageSourceBean的配置，并将其注入到Spring Security的配置中：

@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private MessageSource messageSource;

    @Bean
    public MessageSource messageSource() {
        ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
        messageSource.setBasenames("classpath:messages");
        messageSource.setDefaultEncoding("UTF-8");
        return messageSource;
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
            .anyRequest().authenticated()
            .and()
            .formLogin()
            .loginPage("/login")
            .defaultSuccessUrl("/home")
            .permitAll()
            .and()
            .logout()
            .logoutUrl("/logout")
            .logoutSuccessUrl("/login?logout")
            .permitAll()
            .and()
            .exceptionHandling()
            .accessDeniedPage("/403")
            .and()
            .csrf().disable();
    }

    @Override
    public void configure(WebSecurity web) throws Exception {
        web.ignoring().antMatchers("/webjars/**","/css/**","/js/**");
    }

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

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        LocaleChangeInterceptor localeChangeInterceptor = new LocaleChangeInterceptor();
        localeChangeInterceptor.setParamName("language");
        registry.addInterceptor(localeChangeInterceptor);
    }

    @Bean
    public LocaleResolver localeResolver() {
        CookieLocaleResolver cookieLocaleResolver = new CookieLocaleResolver();
        cookieLocaleResolver.setDefaultLocale(Locale.ENGLISH);
        cookieLocaleResolver.setCookieName("language");
        cookieLocaleResolver.setCookieMaxAge(3600);
        return cookieLocaleResolver;
    }

    @Bean
    public AuthenticationSuccessHandler authenticationSuccessHandler() {
        SavedRequestAwareAuthenticationSuccessHandler authenticationSuccessHandler = new SavedRequestAwareAuthenticationSuccessHandler();
        authenticationSuccessHandler.setTargetUrlParameter("targetUrl");
        return authenticationSuccessHandler;
    }

    @Bean
    public AuthenticationFailureHandler authenticationFailureHandler() {
        SimpleUrlAuthenticationFailureHandler authenticationFailureHandler = new SimpleUrlAuthenticationFailureHandler();
        authenticationFailureHandler.setUseForward(true);
        authenticationFailureHandler.setDefaultFailureUrl("/login?error");
        return authenticationFailureHandler;
    }
}

（2）在项目的资源文件中增加messages.properties和messages_zh_CN.properties两个文件，分别用于英语和中文语言环境的国际化支持。

messages.properties

login.title=Login Page
login.username=Username
login.password=Password
login.signIn=Sign in
login.language=Language
home.title=Home Page
home.welcome=Welcome, {0}!
403.title=Access Denied
403.message=Sorry, you do not have permission to access this page.

messages_zh_CN.properties

login.title=登录页
login.username=用户名
login.password=密码
login.signIn=登录
login.language=语言
home.title=主页
home.welcome=欢迎，{0}！
403.title=拒绝访问
403.message=对不起，你没有权限访问这个页面。

（3）在页面中添加语言环境的切换按钮，并实现其功能，即控制语言环境参数的传递。

<div class="language-switch">
    <a href="?language=en">English</a>
    <span>|</span>
    <a href="?language=zh_CN">中文</a>
</div>

1. UserCache的配置和使用：

UserCache主要用于在一个会话中缓存用户信息，主要配置如下：

（1）在Spring Security的配置文件中增加UserCacheBean的配置，并将其注入到Spring Security的配置中：

@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private UserCache userCache;

    @Bean
    public UserCache userCache() {
        return new HttpSessionUserCache();
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
            .anyRequest().authenticated()
            .and()
            .formLogin()
            .loginPage("/login")
            .defaultSuccessUrl("/home")
            .successHandler(authenticationSuccessHandler())
            .failureHandler(authenticationFailureHandler())
            .permitAll()
            .and()
            .logout()
            .logoutUrl("/logout")
            .logoutSuccessUrl("/login?logout")
            .permitAll()
            .and()
            .exceptionHandling()
            .accessDeniedPage("/403")
            .and()
            .csrf().disable();
    }
}

（2）在登录成功后，通过UserCache缓存用户信息：

@Service
public class AuthenticationUserDetailsService implements UserDetailsService {

    @Autowired
    private UserCache userCache;

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        // 查数据库获取用户信息
        User user = userService.getUserByUsername(username);
        if (user == null) {
            throw new UsernameNotFoundException(username);
        }
        String password = user.getPassword();
        List<GrantedAuthority> authorities = new ArrayList<>();
        authorities.add(new SimpleGrantedAuthority("ROLE_USER"));
        UserDetails userDetails = new User(username, password, authorities);
        userCache.putUserInCache(userDetails);
        return userDetails;
    }
}

（3）在需要使用UserCache缓存的地方，通过UserCache获取缓存的用户信息：

@Controller
public class HomeController {

    @Autowired
    private UserCache userCache;

    @GetMapping("/home")
    public String home(Model model) {
        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
        String username = authentication.getName();
        UserDetails userDetails = userCache.getUserFromCache(username);
        String welcomeMessage = messageSource().getMessage("home.welcome", new Object[]{userDetails.getUsername()}, LocaleContextHolder.getLocale());
        model.addAttribute("welcomeMessage", welcomeMessage);
        return "home";
    }
}

在以上代码中，我们通过UserCache缓存登录成功后的用户信息，在HomeController中的home方法中，通过UserCache获取缓存的用户信息，然后从国际化的资源文件中获取欢迎信息，并添加到model中。