标签:http name provider local ber 对象属性 resource framework jsonview
本文简单介绍如何引入validation的步骤,如何通过自定义validation减少代码量,提高生产力。特别提及:非基本类型属性的valid,GET方法的处理,validation错误信息的统一resolve。
本文中validation的实际实现委托给Hibernate validation处理
<!-- validation begin --> <dependency> <groupId>javax.validation</groupId> <artifactId>validation-api</artifactId> <version>1.1.0.Final</version> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-validator</artifactId> <version>5.4.0.Final</version> </dependency> <!-- validation end -->
在spring-mvc-servlet.xml中增加如下配置:
<mvc:annotation-driven validator="validator"> <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean"> <property name="providerClass" value="org.hibernate.validator.HibernateValidator" /> <property name="validationMessageSource" ref="messageSource"/> </bean> //messageSource 为i18n资源管理bean,见applicationContext.xml配置
个性化处理validation错误信息,返回给调用方的信息更加友好,在applicationContext.xml中增加如下配置:
<!-- 加载i18n消息资源文件 --> <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"> <property name="basenames"> <list> <value>errormsg</value> <value>validation_error</value> </list> </property> </bean> <bean id="validationExceptionResolver" class="com.*.exception.ValidationExceptionResovler"/>
在项目类路径上增加:validation_error_zh_CN.properties资源文件:
#the error msg for input validation
#common field.can.not.be.null={field}不能为空 field.can.not.be.empty={field}不能为空或者空字符串 field.must.be.greater.than.min={field}不能小于{value} field.must.be.letter.than.max={field}不能大于{value}
ValidationExceptionResovler实现:
1 @Slf4j 2 public class ValidationExceptionResovler extends AbstractHandlerExceptionResolver { 3 public ValidationExceptionResovler() { 4 // 设置order,在DefaultHandlerExceptionResolver之前执行 5 this.setOrder(0); 6 } 7 8 /** 9 * Handle the case where an argument annotated with {@code @Valid} such as 10 * an {@link } or {@link } argument fails validation. 11 * <p> 12 * 自定义ValidationException 异常处理器 13 * 获取到具体的validation 错误信息,并组装CommonResponse,返回给调用方。 14 * 15 * @param request current HTTP request 16 * @param response current HTTP response 17 * @param handler the executed handler 18 * @return an empty ModelAndView indicating the exception was handled 19 * @throws IOException potentially thrown from response.sendError() 20 */ 21 @ResponseBody 22 protected ModelAndView handleMethodArgumentNotValidException(BindingResult bindingResult, 23 HttpServletRequest request, 24 HttpServletResponse response, 25 Object handler) 26 throws IOException { 27 28 List<ObjectError> errors = bindingResult.getAllErrors(); 29 StringBuffer errmsgBF = new StringBuffer(); 30 for (ObjectError error : errors) { 31 String massage = error.getDefaultMessage(); 32 errmsgBF.append(massage); 33 errmsgBF.append("||"); 34 } 35 String errmsgString = errmsgBF.toString(); 36 errmsgString = errmsgString.length() > 2 ? errmsgString.substring(0, errmsgString.length() - 2) : errmsgString; 37 log.error("Validation failed! {} ", errmsgString); 38 39 Map<String, Object> map = new TreeMap<String, Object>(); 40 map.put("success", false); 41 map.put("errorCode", "9999"); 42 map.put("errorMsg", errmsgString); 43 44 ModelAndView mav = new ModelAndView(); 45 MappingJackson2JsonView view = new MappingJackson2JsonView(); 46 view.setAttributesMap(map); 47 mav.setView(view); 48 49 return mav; 50 } 51 52 @Override 53 protected ModelAndView doResolveException(HttpServletRequest request, 54 HttpServletResponse response, Object handler, 55 Exception ex) { 56 BindingResult bindingResult = null; 57 if (ex instanceof MethodArgumentNotValidException) { 58 bindingResult = ((MethodArgumentNotValidException) ex).getBindingResult(); 59 } else if(ex instanceof BindException) { 60 bindingResult = ((BindException) ex).getBindingResult(); 61 } else { 62 //other exception , ignore 63 } 64 65 if(bindingResult != null) { 66 try { 67 return handleMethodArgumentNotValidException(bindingResult, request, response, handler); 68 } catch (IOException e) { 69 log.error("doResolveException: ", e); 70 } 71 } 72 73 return null; 74 } 75 }
@RequestMapping("/buy") @ResponseBody public BaseResponse buy(@RequestBody @Valid BuyFlowerRequest request) throws Exception { //...... }
在request bean上为需要validation的属性增加validation注解
@Setter @Getter public class BuyFlowerRequest { @NotEmpty(message = "{name.can.not.be.null}")
private String name;
}
上面的写法,只能对BuyFlowerRequest在基本类型属性上做校验,但是没有办法对对象属性的属性进行validation,如果需要对二级对象的属性进行validation,则需要在二级对象及二级对象属性上同时添加@Valid 和 具体的validation注解.
如下写法:
@Setter @Getter public class BuyFlowerRequest { @NotEmpty(field = "花名") private String name; @Min(field = "价格", value = 1) private int price; @NotNull private List<PayType> payTypeList; } @Setter @Getter public class PayType { @Valid @Min(value = 1) private int payType; @Valid @Min(value = 1) private int payAmount; }
为了减少编码工作量,通过自定义Validation注解,尝试将validation作用的filed名称传递到 错误信息的资源文件中,从而避免为每个域编写不同的message模版.
下面以重写的@NotNull为例讲解:
1、定义Validation注解,注意相比原生注解增加了field(),用于传递被validated的filed名字
@Target( { ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE, ElementType.CONSTRUCTOR, ElementType.PARAMETER }) @Constraint(validatedBy = { NotNullValidator.class }) @Retention(RetentionPolicy.RUNTIME) public @interface NotNull { String field() default ""; String message() default "{field.can.not.be.null}"; Class<?>[] groups() default {}; Class<? extends Payload>[] payload() default {}; }
2、定义Validator,所有的Validator均实现ConstraintValidator接口:
1 public class NotNullValidator implements ConstraintValidator<NotNull, Object> { 2 3 @Override 4 public void initialize(NotNull annotation) { 5 6 } 7 8 @Override 9 public boolean isValid(Object str, ConstraintValidatorContext constraintValidatorContext) { 10 return str != null; 11 } 12 13 }
3、在filed上加入Validation注解,注意指定filed值,message如果没有个性化需求,可以不用指明,validation组件会自行填充default message。
@Setter @Getter public class BuyFlowerRequest { @NotEmpty(field = "花名") private String name; @Min(field = "价格", value = 1) private int price; }
注:@NotNull注解已经支持对list的特殊校验,对于List类型节点,如果list==null || list.size() == 0都会返回false,validation失败。目前已按照此思路自定义实现了@NotNull、@NotEmpty、@Min、@Max注解,在goods工程中可以找到.
上面的示例都是POST请求,@RequestBody可以 resolve POST请求,但是不支持GET请求,阅读spring的文档和源码,发现@ModelAttribute可以将GET请求resolve成Bean,且支持Validation。具体可以翻阅spring源码:ModelAttributeMethodProcessor.resolveArgument()方法。
使用示例:
@RequestMapping(value = "/buy", method = RequestMethod.GET) @ResponseBody public BaseResponse detail(@Valid @ModelAttribute DetailFlowerRequest request) throws Exception { DetailFlowerResponse response = new DetailFlowerResponse(); response.setName(request.getName()); return ResultFactory.success(response, BaseResponse.class); }
1、根据业务场景扩展validation,如:日期格式、金额等
2、支持多个field关系校验的validation
@RequestBody
实现类:RequestResponseBodyMethodProcessor.java
public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
Object arg = this.readWithMessageConverters(webRequest, parameter, parameter.getGenericParameterType());
String name = Conventions.getVariableNameForParameter(parameter);
WebDataBinder binder = binderFactory.createBinder(webRequest, arg, name);
if (arg != null) {
this.validateIfApplicable(binder, parameter);
if (binder.getBindingResult().hasErrors() && this.isBindExceptionRequired(binder, parameter)) {
throw new MethodArgumentNotValidException(parameter, binder.getBindingResult());
}
}
mavContainer.addAttribute(BindingResult.MODEL_KEY_PREFIX + name, binder.getBindingResult());
return arg;
}
@ModelAttibute
实现类:ModelAttributeMethodProcessor.java
public final Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
String name = ModelFactory.getNameForParameter(parameter);
Object attribute = mavContainer.containsAttribute(name) ? mavContainer.getModel().get(name) : this.createAttribute(name, parameter, binderFactory, webRequest);
if (!mavContainer.isBindingDisabled(name)) {
ModelAttribute ann = (ModelAttribute)parameter.getParameterAnnotation(ModelAttribute.class);
if (ann != null && !ann.binding()) {
mavContainer.setBindingDisabled(name);
}
}
WebDataBinder binder = binderFactory.createBinder(webRequest, attribute, name);
if (binder.getTarget() != null) {
if (!mavContainer.isBindingDisabled(name)) {
this.bindRequestParameters(binder, webRequest);
}
this.validateIfApplicable(binder, parameter);
if (binder.getBindingResult().hasErrors() && this.isBindExceptionRequired(binder, parameter)) {
throw new BindException(binder.getBindingResult());
}
}
Map<String, Object> bindingResultModel = binder.getBindingResult().getModel();
mavContainer.removeAttributes(bindingResultModel);
mavContainer.addAllAttributes(bindingResultModel);
return binder.convertIfNecessary(binder.getTarget(), parameter.getParameterType(), parameter);
}
标签:http name provider local ber 对象属性 resource framework jsonview
原文地址:https://www.cnblogs.com/daoqidelv/p/9061862.html