Hibernate Validation使用示例及讲解

http://wdmcygah.iteye.com/blog/2174680

备注：
（1）上述示例只是展示了Hibernate Validation比较常用的示例，框架其实还支持方法返回值、方法参数校验，另外也可以通过XML进行配置，校验还可以分组、合并等等。这些内容请查阅官方使用手册。
一、依赖包

J2SE环境下除了需要引入Hibernate Validation包外，还需要额外引入两个实现表达式语言的包。J2EE环境如果容器提供不需要再引入。下面是J2SE环境下的依赖包：

<dependency>  
            <groupId>org.hibernate</groupId>  
            <artifactId>hibernate-validator</artifactId>  
            <version>5.1.3.Final</version>  
        </dependency>  
        <dependency>  
            <groupId>javax.el</groupId>  
            <artifactId>javax.el-api</artifactId>  
            <version>2.2.4</version>  
        </dependency>  
        <dependency>  
            <groupId>org.glassfish.web</groupId>  
            <artifactId>javax.el</artifactId>  
            <version>2.2.4</version>  
        </dependency> 

二、校验工具类

工具类提供了校验实体类、实体字段的方法，返回一个自定义的校验对象。

/** 
 * 校验工具类 
 * @author wdmcygah 
 * 
 */  
public class ValidationUtils {  
  
    private static Validator validator =  Validation.buildDefaultValidatorFactory().getValidator();  
      
    public static <T> ValidationResult validateEntity(T obj){  
        ValidationResult result = new ValidationResult();  
         Set<ConstraintViolation<T>> set = validator.validate(obj,Default.class);  
         if( CollectionUtils.isNotEmpty(set) ){  
             result.setHasErrors(true);  
             Map<String,String> errorMsg = new HashMap<String,String>();  
             for(ConstraintViolation<T> cv : set){  
                 errorMsg.put(cv.getPropertyPath().toString(), cv.getMessage());  
             }  
             result.setErrorMsg(errorMsg);  
         }  
         return result;  
    }  
      
    public static <T> ValidationResult validateProperty(T obj,String propertyName){  
        ValidationResult result = new ValidationResult();  
         Set<ConstraintViolation<T>> set = validator.validateProperty(obj,propertyName,Default.class);  
         if( CollectionUtils.isNotEmpty(set) ){  
             result.setHasErrors(true);  
             Map<String,String> errorMsg = new HashMap<String,String>();  
             for(ConstraintViolation<T> cv : set){  
                 errorMsg.put(propertyName, cv.getMessage());  
             }  
             result.setErrorMsg(errorMsg);  
         }  
         return result;  
    }  
}  

三、校验返回对象

/** 
 * 校验结果 
 * @author wdmcygah 
 * 
 */  
public class ValidationResult {  
  
    //校验结果是否有错  
    private boolean hasErrors;  
      
    //校验错误信息  
    private Map<String,String> errorMsg;  
  
    public boolean isHasErrors() {  
        return hasErrors;  
    }  
  
    public void setHasErrors(boolean hasErrors) {  
        this.hasErrors = hasErrors;  
    }  
  
    public Map<String, String> getErrorMsg() {  
        return errorMsg;  
    }  
  
    public void setErrorMsg(Map<String, String> errorMsg) {  
        this.errorMsg = errorMsg;  
    }  
  
    @Override  
    public String toString() {  
        return "ValidationResult [hasErrors=" + hasErrors + ", errorMsg="  
                + errorMsg + "]";  
    }  
  
}

四、被校验实体

public class SimpleEntity {  
  
    @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;  
      
    @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;  
    
       //get set方法省略，自己添加  
}  

有些情况下，Hibernate Validation自带的注解不能够满足需求，我们想定制一个注解进行使用，此时可以参考下面的示例（自定义密码注解及校验规则）。

一、密码注解

package research.hibernate.validation.extend;  
  
import static java.lang.annotation.ElementType.ANNOTATION_TYPE;  
import static java.lang.annotation.ElementType.FIELD;  
import static java.lang.annotation.ElementType.METHOD;  
import static java.lang.annotation.RetentionPolicy.RUNTIME;  
  
import java.lang.annotation.Documented;  
import java.lang.annotation.Retention;  
import java.lang.annotation.Target;  
  
import javax.validation.Constraint;  
import javax.validation.Payload;  
  
@Target( { METHOD, FIELD, ANNOTATION_TYPE })  
@Retention(RUNTIME)  
@Constraint(validatedBy = PasswordValidator.class)  
@Documented  
public @interface Password {  
  
    String message() default "{密码必须是5~10位数字和字母组合}";  
  
    Class<?>[] groups() default {};  
  
    Class<? extends Payload>[] payload() default {};  
}  

二、密码校验类

/** 
 * 自定义密码校验类 
 * @author wdmcygah 
 * 
 */  
public class PasswordValidator implements ConstraintValidator<Password, String> {  
  
    //5~10位的数字与字母组合  
    private static Pattern pattern = Pattern.compile("(?![0-9]+$)(?![a-zA-Z]+$)[0-9A-Za-z]{5,10}");  
      
    public void initialize(Password constraintAnnotation) {  
        //do nothing  
    }  
  
    public boolean isValid(String value, ConstraintValidatorContext context) {  
        if( value==null ){  
            return false;  
        }  
        Matcher m = pattern.matcher(value);  
        return m.matches();  
    }     
}  

三、被校验实体

public class ExtendEntity {  
  
    @Password  
    private String password;  
      
    public String getPassword() {  
        return password;  
    }  
  
    public void setPassword(String password) {  
        this.password = password;  
    }  
  
}  

对应的测试类如下：

public class ValidationUtilsTest extends TestCase{  
  
  public void validateSimpleEntity() {  
      SimpleEntity se = new SimpleEntity();  
      se.setDate(new Date());  
      se.setEmail("123");  
      se.setName("123");  
      se.setPassword("123");  
      se.setValid(false);  
      ValidationResult result = ValidationUtils.validateEntity(se);  
      System.out.println("--------------------------");  
      System.out.println(result);  
      Assert.assertTrue(result.isHasErrors());  
  }  
    
  public void validateSimpleProperty() {  
      SimpleEntity se = new SimpleEntity();  
      ValidationResult result = ValidationUtils.validateProperty(se,"name");  
      System.out.println("--------------------------");  
      System.out.println(result);  
      Assert.assertTrue(result.isHasErrors());  
  }  
    
  public void validateExtendEntity() {  
      ExtendEntity ee = new ExtendEntity();  
      ee.setPassword("212");  
      ValidationResult result = ValidationUtils.validateEntity(ee);  
      System.out.println("--------------------------");  
      System.out.println(result);  
      Assert.assertTrue(result.isHasErrors());  
  }  
}