import java.io.Serializable;
import java.util.Date;import javax.validation.constraints.Future;
import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Past;
import javax.validation.constraints.Pattern;
import javax.validation.constraints.Size;public class ValidationParameter implements Serializable {private static final long serialVersionUID = 7158911668568000392L;@NotNull // 不允许为空@Size(min = 1, max = 20) // 长度或大小范围private String name;@NotNull(groups = ValidationService.Save.class) // 保存时不允许为空，更新时允许为空 ，表示不更新该字段@Pattern(regexp = "^\\s*\\w+(?:\\.{0,1}[\\w-]+)*@[a-zA-Z0-9]+(?:[-.][a-zA-Z0-9]+)*\\.[a-zA-Z]+\\s*$")private String email;@Min(18) // 最小值@Max(100) // 最大值private int age;@Past // 必须为一个过去的时间private Date loginDate;@Future // 必须为一个未来的时间private Date expiryDate;public String getName() {return name;}public void setName(String name) {this.name = name;}public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public Date getLoginDate() {return loginDate;}public void setLoginDate(Date loginDate) {this.loginDate = loginDate;}public Date getExpiryDate() {return expiryDate;}public void setExpiryDate(Date expiryDate) {this.expiryDate = expiryDate;}}

public interface ValidationService { // 缺省可按服务接口区分验证场景，如：@NotNull(groups = ValidationService.class)
     @interface Save{} // 与方法同名接口，首字母大写，用于区分验证场景，如：@NotNull(groups = ValidationService.Save.class)，可选void save(ValidationParameter parameter);void update(ValidationParameter parameter);}

import javax.validation.GroupSequence;public interface ValidationService {@GroupSequence(Update.class) // 同时验证Update组规则@interface Save{}void save(ValidationParameter parameter);@interface Update{} void update(ValidationParameter parameter);}

import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;public interface ValidationService {void save(@NotNull ValidationParameter parameter); // 验证参数不为空
 void delete(@Min(1) int id); // 直接对基本类型参数验证

}

<dubbo:reference id="validationService" interface="com.alibaba.dubbo.examples.validation.api.ValidationService" validation="true" />

<dubbo:service interface="com.alibaba.dubbo.examples.validation.api.ValidationService" ref="validationService" validation="true" />

import javax.validation.ConstraintViolationException;
import javax.validation.ConstraintViolationException;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.alibaba.dubbo.examples.validation.api.ValidationParameter;
import com.alibaba.dubbo.examples.validation.api.ValidationService;
import com.alibaba.dubbo.rpc.RpcException;public class ValidationConsumer {public static void main(String[] args) throws Exception {String config = ValidationConsumer.class.getPackage().getName().replace('.', '/') + "/validation-consumer.xml";ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(config);context.start();ValidationService validationService = (ValidationService)context.getBean("validationService");// Errortry {parameter = new ValidationParameter();validationService.save(parameter);System.out.println("Validation ERROR");} catch (RpcException e) { // 抛出的是RpcExceptionConstraintViolationException ve = (ConstraintViolationException) e.getCause(); // 里面嵌了一个ConstraintViolationExceptionSet<ConstraintViolation<?>> violations = ve.getConstraintViolations(); // 可以拿到一个验证错误详细信息的集合
            System.out.println(violations);}}}

<dependency><groupId>javax.validation</groupId><artifactId>validation-api</artifactId><version>1.0.0.GA</version>
</dependency>
<dependency><groupId>org.hibernate</groupId><artifactId>hibernate-validator</artifactId><version>4.2.0.Final</version>
</dependency>