hibernate validator是Bean Validation 1.1 (JSR 349) Reference Implementation，其广泛的应用在mvc的参数校验中，尤其是使用服务端spring mvc模板的时候。在这里，我们要讲的不是如何使用的问题。而是如何基于其提供更加符合项目要求以及最小化重复实现的目标，在不少情况下，我们在不同的服务中，对于相同的请求类Req，对于其中不同字段的校验要求是不同的，比如有些时候name字段是必须的，但其他情况下是非必须的，所以需要跟着服务或者服务组进行校验。再如，几乎每个系统都会使用到数据字典，使用数据字典的时候，有两种方式可以校验其取值范围，一种是直接使用java枚举类型，另外一种是人工进行判断。只不过，我们不建议使用枚举类型，但是我们也希望能够和通用的参数一样进行校验，而不是对于数据字典进行特殊校验。对于这两种情况，都可以在hibernate validator的技术上实现。对于服务分组，可以新增一个注解比如ValidServices实现，对于枚举校验，可以增加一个自定义的校验注解实现，如下：

ValidServices.java

package tf56.lf.base.metadata.validate;import java.lang.annotation.Retention;import java.lang.annotation.Target;import java.lang.annotation.ElementType;import java.lang.annotation.RetentionPolicy;/** * 参数校验分组注解 * @author admin * */@Target({ElementType.FIELD})@Retention(value = RetentionPolicy.RUNTIME)public @interface ValidServices {    String[] services();}

package tf56.lf.base.metadata.validate;import java.util.Map;public class ValidationResult {    // 校验结果是否有错    private boolean success = true;    // 校验错误信息    private Map
     
       errorPair;    public boolean isSuccess() {        return success;    }    public void setSuccess(boolean success) {        this.success = success;    }    public Map
      
        getErrorPair() {        return errorPair;    }    public void setErrorPair(Map
       
         errorPair) {        this.errorPair = errorPair;    }}
       
      
     

Dict.java

package tf56.lf.base.metadata.validate;import java.lang.annotation.Documented;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;import javax.validation.Constraint;import javax.validation.Payload;@Target({ElementType.FIELD})@Retention(value = RetentionPolicy.RUNTIME)@Constraint(validatedBy = { DictValidator.class })@Documentedpublic @interface Dict {        String dictName();        String message() default "{数据字典取值不合法,请参考标准数据字典管理}";    Class
     [] groups() default {};    Class
     [] payload() default {};}

DictValidator：

package tf56.lf.base.metadata.validate;import javax.validation.ConstraintValidator;import javax.validation.ConstraintValidatorContext;import tf56.lf.base.metadata.cons.DictUtils;public class DictValidator implements ConstraintValidator
     
       {        private String dictName;        @Override    public void initialize(Dict dictAnno) {        this.dictName = dictAnno.dictName();    }    @Override    public boolean isValid(String value, ConstraintValidatorContext context) {        if (DictUtils.isValid(dictName, value)) {            return true;        }        context.disableDefaultConstraintViolation();        context.buildConstraintViolationWithTemplate("该字段的当前值" + value + "不在数据字典" + dictName + "的有效取值范围内, 有效值为:[" + DictUtils.getDictKeys(dictName) + "]").addConstraintViolation();        return false;    }}
     

DictUtils为字典取值范围校验类，每个公司的实现不同，读者自己构建一个即可。

主类：

package tf56.lf.common.util;import java.lang.reflect.Field;import java.util.Date;import java.util.HashMap;import java.util.HashSet;import java.util.Map;import java.util.Set;import java.util.concurrent.ConcurrentHashMap;import javax.validation.ConstraintViolation;import javax.validation.Validation;import javax.validation.Validator;import javax.validation.constraints.AssertTrue;import javax.validation.constraints.Past;import javax.validation.constraints.Pattern;import javax.validation.groups.Default;import org.apache.commons.collections.CollectionUtils;import org.hibernate.validator.constraints.Email;import org.hibernate.validator.constraints.Length;import org.hibernate.validator.constraints.NotBlank;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import tf56.lf.base.metadata.validate.Dict;import tf56.lf.base.metadata.validate.ValidServices;import tf56.lf.base.metadata.validate.ValidationResult;import tf56.lf.common.cons.SpiderSystemError;import tf56.lf.common.exception.LfException;public class ValidationUtils {        private static Map
     
      
       > validFields = new ConcurrentHashMap
       
        
         >();        static final Logger logger = LoggerFactory.getLogger(ValidationUtils.class);        private static Validator validator = Validation            .buildDefaultValidatorFactory().getValidator();    public static 
         
           ValidationResult validateEntity(String serviceId,T obj) {        boolean noNeedCheck = true;        Map
          
            errorMsg = new HashMap
           
            (); Field[] fields = obj.getClass().getDeclaredFields(); for(int i=0;i
            
              services = new HashSet
             
              (); ValidServices serviceAnno = fields[i].getAnnotation(ValidServices.class); if (serviceAnno != null) { for (int j=0;j
              
                errorPair = validatePropertyInternal(serviceId,obj,fields[i].getName()); errorMsg.putAll(errorPair); } } if (noNeedCheck) { logger.warn("服务" + serviceId + "在" + obj.getClass().getCanonicalName() + "中所有字段都没有配置做任何校验."); } ValidationResult result = new ValidationResult(); if (!errorMsg.isEmpty()) { result.setErrorPair(errorMsg); result.setSuccess(false); } return result; } private static 
               
                 Map
                
                  validatePropertyInternal(String serviceId, T obj, String propertyName) { Set
                 
                  
                   > set = validator.validateProperty(obj, propertyName, Default.class); Map
                   
                     errorMsg = new HashMap
                    
                     (); if (CollectionUtils.isNotEmpty(set)) { for (ConstraintViolation
                     
                       cv : set) { errorMsg.put(propertyName, cv.getMessage()); } } return errorMsg; } public static 
                      
                        ValidationResult validateProperty(String serviceId, T obj, String propertyName) { ValidationResult result = new ValidationResult(); Field field = null; try { field = obj.getClass().getDeclaredField(propertyName); } catch (NoSuchFieldException | SecurityException e) { throw new LfException(SpiderSystemError.ERR_NO_SUCH_FIELD_OR_FORBIDDEN); } if(validFields.get(field) == null) { Set
                       
                         services = new HashSet
                        
                         (); ValidServices serviceAnno = field.getAnnotation(ValidServices.class); if (serviceAnno != null) { for (int i=0;i
                         
                           errorPair = validatePropertyInternal(serviceId,obj,field.getName()); if (!errorPair.isEmpty()) { result.setErrorPair(errorPair); result.setSuccess(false); } } return result; } public static void main(String[] args) { SimpleEntity entity = new SimpleEntity(); entity.setValid(true); ValidationResult result = ValidationUtils.validateEntity("1001",entity); if (!result.isSuccess()) { System.out.println(FastJsonUtil.serializeFromObject(result.getErrorPair())); } result = ValidationUtils.validateEntity("100",entity); if (!result.isSuccess()) { System.out.println(FastJsonUtil.serializeFromObject(result.getErrorPair())); } entity = new SimpleEntity(); entity.setValid(true); result = ValidationUtils.validateEntity("1",entity); if (!result.isSuccess()) { System.out.println(FastJsonUtil.serializeFromObject(result.getErrorPair())); } } public static class SimpleEntity { @ValidServices(services = { "1001","1002" }) @NotBlank(message="名字不能为空或者空串") @Length(min=2,max=10,message="名字必须由2~10个字组成") private String name; @Dict(dictName = "payType") private String payType; @Past(message="时间不能晚于当前时间") private Date date; @Email(message="邮箱格式不正确") private String email; @Pattern(regexp="(?![0-9]+$)(?![a-zA-Z]+$)[0-9A-Za-z]{5,10}",message="密码必须是5~10位数字和字母的组合") private String password; @AssertTrue(message="字段必须为真") private boolean valid; public String getName() { return name; } public void setName(String name) { this.name = name; } public Date getDate() { return date; } public void setDate(Date date) { this.date = date; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public boolean isValid() { return valid; } public void setValid(boolean valid) { this.valid = valid; } }}
                         
                        
                       
                      
                     
                    
                   
                  
                 
                
               
              
             
            
           
          
         
        
       
      
     

输出如下：

{"name":"名字不能为空或者空串","payType":"该字段的当前值null不在数据字典payType的有效取值范围内, 有效值为:[OTHER,BANK,CASH,TF_ACCOUNT]"}

{"payType":"该字段的当前值null不在数据字典payType的有效取值范围内, 有效值为:[OTHER,BANK,CASH,TF_ACCOUNT]"}

{"payType":"该字段的当前值null不在数据字典payType的有效取值范围内, 有效值为:[OTHER,BANK,CASH,TF_ACCOUNT]"}