Spring Boot 实现国际化消息提示
前言
本文介绍使用Spring Boot实现国际化信息(i18n)提示。
Spring Boot 官方文档中关于国际化的文档资料：boot-features-internationalization
默认国际化配置
SpringBoot提供了自动配置类org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration。
可以看到自动配置类中提供的可配置参数为spring.messages，其中典型配置为：
#默认配置国际化文件路径
spring.messages.basename=messages
默认将读取resources名为messages的Resource Bundle文件。
如果要使用该自动化配置的国际化资源，注入org.springframework.context.MessageSource实例即可。
自定义国际化配置
如果需要更灵活的国际化配置，可以自行指定对应的国际化资源配置，自行读取。
这里以一个动态响应错误信息的国际化示例为例。
创建ResultCodeMessages国际化文件
在resources目录下创建i18n文件夹，用于存放国际化文件。
在i18n目录下创建名为ResultCodeMessages的Resource Bundle文件。
ResultCodeMessages.properties
00=success
97=request param error
98=not found
99=fail. arg : {0} , {1}
ResultCodeMessages_en.properties
#同ResultCodeMessages.properties，这里默认Locale为ENGLISH
00=success
97=request param error
98=not found
99=fail. arg : {0} , {1}
ResultCodeMessages_zh_CN.properties
00=成功
97=请求入参校验出错
98=未找到
99=失败。错了，说点啥吧：{0}，{1}
创建标准响应结果类和响应码枚举类
响应码枚举类
public enum ResultCodeEnum {
//成功
SUCCESS("00"),
//失败
FAIL("99"),
//未找到
NOT_FOUND("98"),
//请求入参校验出错
REQUEST_PARAM_ERROR("97");
private final String code;
public String getCode() {
return code;
}
ResultCodeEnum(String code) {
this.code = code;
}
public static ResultCodeEnum getEnum(String code) {
for (ResultCodeEnum resultCodeEnum : ResultCodeEnum.values()) {
if (resultCodeEnum.getCode().equals(code)) {
return resultCodeEnum;
}
}
return null;
}
}
标准响应结果类
@Data
@JsonInclude(JsonInclude.Include.NON_NULL)
public class ApiResult<T> implements Serializable {
private String code;
private String message;
@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
private LocalDateTime timestamp;
private T data;
private ApiResult(String code, String message, T data) {
this.code = code;
this.message = message;
this.timestamp = LocalDateTime.now();
this.data = data;
}
public static <T> ApiResult<T> success(T data) {
return new ApiResult<>(ResultCodeEnum.SUCCESS.getCode(), null, data);
}
public static ApiResult<Void> fail(String code, String message) {
return new ApiResult<>(code, message, null);
}
}
自定义国际化拦截器
Spring Boot中国际化拦截器默认为org.springframework.web.servlet.i18n.LocaleChangeInterceptor，默认国际化参数为URL参数locale。
这里自定义修改国际化拦截器，默认国际化参数为URL参数（可以修改为从请求头获取），这里不做实质上的修改
public class CustomizeLocaleChangeInterceptor extends LocaleChangeInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws ServletException {
//从URL参数中获取
String newLocale = request.getParameter(getParamName());
//可修改成从请求头获取
//String newLocale = request.getHeader(getParamName());
if (newLocale != null) {
if (checkHttpMethod(request.getMethod())) {
LocaleResolver localeResolver = RequestContextUtils.getLocaleResolver(request);
if (localeResolver == null) {
throw new IllegalStateException(
"No LocaleResolver found: not in a DispatcherServlet request?");
}
try {
localeResolver.setLocale(request, response, parseLocaleValue(newLocale));
} catch (IllegalArgumentException ex) {
if (isIgnoreInvalidLocale()) {
if (logger.isDebugEnabled()) {
logger.debug("Ignoring invalid locale value [" + newLocale + "]: " + ex.getMessage());
}
} else {
throw ex;
}
}
}
}
// Proceed in any case.
return true;
}
private boolean checkHttpMethod(String currentMethod) {
String[] configuredMethods = getHttpMethods();
if (ObjectUtils.isEmpty(configuredMethods)) {
return true;
}
for (String configuredMethod : configuredMethods) {
if (configuredMethod.equalsIgnoreCase(currentMethod)) {
return true;
}
}
return false;
}
}
注册自定义国际化拦截器
@Configuration
public class WebConfiguration implements WebMvcConfigurer {
@Resource(name = "customizeLocaleChangeInterceptor")
LocaleChangeInterceptor localeChangeInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(localeChangeInterceptor);
}
}
国际化配置
i18n配置
@Configuration
public class LocaleConfig {
/**
* 默认本地化解析器
*/
@Bean
public LocaleResolver localeResolver() {
SessionLocaleResolver localeResolver = new SessionLocaleResolver();
//指定默认语言
localeResolver.setDefaultLocale(Locale.ENGLISH);
return localeResolver;
}
/**
* 默认本地化拦截器
*/
@Bean("customizeLocaleChangeInterceptor")
public LocaleChangeInterceptor localeChangeInterceptor() {
CustomizeLocaleChangeInterceptor localeChangeInterceptor = new CustomizeLocaleChangeInterceptor();
//自定义国际化参数
localeChangeInterceptor.setParamName("language");
return localeChangeInterceptor;
}
// result code : 响应码信息国际化配置
@Bean("resultCodeMessageResource")
public MessageSource resultCodeMessageResource() {
ResourceBundleMessageSource resourceBundleMessageSource = new ResourceBundleMessageSource();
//指定国际化的Resource Bundle地址
resourceBundleMessageSource.setBasename("i18n/ResultCodeMessages");
//指定国际化的默认编码
resourceBundleMessageSource.setDefaultEncoding("UTF-8");
return resourceBundleMessageSource;
}
@Bean("resultCodeLocaleMessage")
public LocaleMessage resultCodeLocaleMessage() {
return new LocaleMessage(resultCodeMessageResource());
}
}
国际化资源工具类
public class LocaleMessage {
private final MessageSource messageSource;
public LocaleMessage(MessageSource messageSource) {
this.messageSource = messageSource;
}
public String getMessage(String code) {
return getMessage(code, new Object[]{});
}
public String getMessage(String code, String defaultMessage) {
return getMessage(code, new Object[]{}, defaultMessage);
}
public String getMessage(String code, String defaultMessage, Locale locale) {
return getMessage(code, new Object[]{}, defaultMessage, locale);
}
public String getMessage(String code, Locale locale) {
return getMessage(code, new Object[]{}, "", locale);
}
public String getMessage(String code, Object[] args) {
return getMessage(code, args, "");
}
public String getMessage(String code, Object[] args, Locale locale) {
return getMessage(code, args, "", locale);
}
public String getMessage(String code, Object[] args, String defaultMessage) {
//根据应用部署的服务器系统来决定国际化
return getMessage(code, args, defaultMessage, LocaleContextHolder.getLocale());
}
public String getMessage(String code, Object[] args, String defaultMessage, Locale locale) {
return messageSource.getMessage(code, args == null ? new Object[]{} : args, defaultMessage, locale);
}
}
全局统一异常处理
业务异常类
public class BusinessException extends RuntimeException {
private final String resultCode;
private final Object[] args;
public String getResultCode() {
return resultCode;
}
public Object[] getArgs() {
return args;
}
public BusinessException(ResultCodeEnum resultCodeEnum, Object[] args) {
this.resultCode = resultCodeEnum.getCode();
this.args = args;
}
public BusinessException(String code, Object[] args) {
this.resultCode = code;
this.args = args;
}
public static void throwMessage(String errorCode, Object[] args) {
throw new BusinessException(errorCode, args);
}
public static void throwMessage(ResultCodeEnum resultCodeEnum, Object[] args) {
throw new BusinessException(resultCodeEnum.getCode(), args);
}
}
统一异常处理
@Slf4j
@RestControllerAdvice
class GlobalExceptionHandler {
@Resource(name = "resultCodeLocaleMessage")
LocaleMessage resultCodeLocaleMessage;
@ExceptionHandler(BindException.class)
public ApiResult<Void> handlerBindExceptionHandler(HttpServletRequest req, final BindException e) {
log.error(req.getServletPath() + " Bind Exception", e);
String message = e.getBindingResult().getAllErrors().stream().map(DefaultMessageSourceResolvable::getDefaultMessage).collect(Collectors.joining(";"));
return ApiResult.fail(ResultCodeEnum.REQUEST_PARAM_ERROR.getCode(), message);
}
@ExceptionHandler(MethodArgumentNotValidException.class)
public ApiResult<Void> handlerMethodArgumentNotValidException(HttpServletRequest req, final MethodArgumentNotValidException e) {
log.error(req.getServletPath() + " MethodArgumentNotValid Exception", e);
String message = e.getBindingResult().getAllErrors().stream().map(ObjectError::getDefaultMessage).collect(Collectors.joining(";"));
return ApiResult.fail(ResultCodeEnum.REQUEST_PARAM_ERROR.getCode(), message);
}
@ExceptionHandler(BusinessException.class)
public ApiResult<Void> handlerBusinessException(HttpServletRequest req, final BusinessException e) {
log.error(req.getServletPath() + " Business Exception", e);
return ApiResult.fail(e.getResultCode(), resultCodeLocaleMessage.getMessage(e.getResultCode(), e.getArgs(), RequestContextUtils.getLocale(req)));
}
}
请求示例
@GetMapping("/success")
public ApiResult<String> success() {
return ApiResult.success("success");
}
@GetMapping("/fail")
public void fail(@RequestParam(value = "code", required = false, defaultValue = "99") String code,
@RequestParam(value = "content", required = false, defaultValue = "错了吧，说点啥吧") List<String> contentList) {
BusinessException.throwMessage(code, contentList.toArray());
}
http测试示例
### 测试成功响应
GET http://localhost:8080/success HTTP/1.1
### 测试中文，响应码99
GET http://localhost:8080/fail?language=zh_CN&code=99&content=我没错&content=是系统的错 HTTP/1.1
### 测试英文，响应码99
GET http://localhost:8080/fail?language=en&code=99&content=I'm not wrong&content=It's the system's fault HTTP/1.1
示例
项目Demo：internationalization
效果图：
参考
- SpringBoot项目国际化