你能在运行时更改注释消息吗？ [英] Can you change an annotation message at run time?

问题描述

我正在尝试在我的注释中包含一个动态消息，该消息根据传递给它的其他变量中的值来更改文本的主体。我设置了默认消息，但是当设置了某个指示符时，我想显示不同的消息。这可能吗？

这是我的注释 -

  @Target（{TYPE，ANNOTATION_TYPE }）
 @Retention（RUNTIME）
 @Constraint（validatedBy = FieldMatchValidator.class）
 @Documented 
 public @interface FieldMatch 
 {
 Class<？ > [] groups（）默认{}; 
等级<？扩展Payload> [] payload（）default {}; 
 String first（）; 
 String second（）; 
 String third（）default; 
 String match（）默认为true; 
 String message（）默认{error.theseValuesDontMatch}; 
 
 / ** 
 *定义几个< code> @ FieldMatch< / code>同一元素上的注释
 * 
 * @see FieldMatch 
 * / 
 @Target（{TYPE，ANNOTATION_TYPE}）
 @Retention（RUNTIME）
 @Documented @interface List 
 {
 FieldMatch [] value（）; 
} 
} 
  

这是注释使用的验证器类 -

 公共类FieldMatchValidator实现ConstraintValidator< FieldMatch，Object> 
 {
 private String firstFieldName; 
 private String secondFieldName; 
 private String thirdFieldName; 
 private String match; 
私有字符串消息; 
 
 @Override 
 public void initialize（FieldMatch constraintAnnotation）
 {
 firstFieldName = constraintAnnotation.first（）; 
 secondFieldName = constraintAnnotation.second（）; 
 thirdFieldName = constraintAnnotation.third（）; 
 match = constraintAnnotation.match（）; 
 if（match！= null&&！Boolean.getBoolean（match））{
 message =error.theseValuesMustNotMatch; 
} 
} 
 
 @Override 
 public boolean isValid（final Object value，final ConstraintValidatorContext context）
 {
 try 
 {
 final Object firstObj = BeanUtils.getProperty（value，firstFieldName）; 
 final Object secondObj = BeanUtils.getProperty（value，secondFieldName）; 
 final Object thirdObj = BeanUtils.getProperty（value，thirdFieldName）; 
 final String same = BeanUtils.getProperty（value，match）; 
 
 boolean valid = false; 
 if（same！= null&& Boolean.getBoolean（same））{
 if（。equals（thirdObj））{
 valid = firstObj == null&& ; secondObj == null || firstObj！= null&& firstObj.equals（secondObj）; 
} 
 else {
 valid = firstObj！= null&& firstObj.equals（secondObj）&& firstObj.equals（thirdObj）; 
} 
} 
 else {
 if（。equals（thirdObj））{
 valid = firstObj == null&& secondObj == null || firstObj！= null&& ！firstObj.equals（secondObj）; 
} 
 else {
 valid = firstObj！= null&& ！（firstObj.equals（secondObj）&& firstObj.equals（thirdObj））; 
} 
} 
返回有效; 
} 
 catch（最终忽略异常）
 {
 //忽略
} 
返回true; 
} 
} 
  

我最感兴趣的是代码如果（匹配！= null&&！Boolean.getBoolean（match））{
message =password.error.theseValuesMustNotMatch;
}

解决方案

以下是我的能力这样做 -

  @Override 
 public void initialize（FieldMatch constraintAnnotation）
 {
 firstFieldName = constraintAnnotation.first（）; 
 secondFieldName = constraintAnnotation.second（）; 
 thirdFieldName = constraintAnnotation.third（）; 
 match = constraintAnnotation.match（）; 
 
 //在初始化时设置消息变量
 if（true.equals（match））{
 message = constraintAnnotation.message（）; 
} 
 else {
 message ={password.error.threeQuestionsSameAnswer};} 
} 
 
 @Override 
 public boolean isValid （final Object value，final ConstraintValidatorContext context）
 {
 Object firstObj = null; 
 Object secondObj = null; 
 Object thirdObj = null; 
 
 //禁用现有违规消息
 context.disableDefaultConstraintViolation（）; 
 //构建新的违规消息并添加它
 context.buildConstraintViolationWithTemplate（message）.addConstraintViolation（）; 
 
等......... 
} 
  

I'm trying to include a dynamic message in my annotation that changes the main body of the text based on the values that are found in the other variables that are passed to it. I set a default message, but when a certain indicator is set, I want to display a different message. Is this possible?

Here's my annotation -

@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = FieldMatchValidator.class)
@Documented
public @interface FieldMatch
{
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};
    String first();
    String second();
    String third() default "";
    String match() default "true";
    String message() default "{error.theseValuesDontMatch}";

    /**
     * Defines several <code>@FieldMatch</code> annotations on the same element
     *
     * @see FieldMatch
     */
    @Target({TYPE, ANNOTATION_TYPE})
    @Retention(RUNTIME)
    @Documented @interface List
    {
        FieldMatch[] value();
    }
}

Here's the validator class used by the annotation -

public class FieldMatchValidator implements ConstraintValidator<FieldMatch, Object>
{
    private String firstFieldName;
    private String secondFieldName;
    private String thirdFieldName;
    private String match;
    private String message;

    @Override
    public void initialize(FieldMatch constraintAnnotation)
    {
        firstFieldName = constraintAnnotation.first();
        secondFieldName = constraintAnnotation.second();
        thirdFieldName = constraintAnnotation.third();
        match = constraintAnnotation.match();
        if(match != null && !Boolean.getBoolean(match)){
            message = "error.theseValuesMustNotMatch";
        }
    }

    @Override
    public boolean isValid(final Object value, final ConstraintValidatorContext context)
    {
        try
        {
            final Object firstObj = BeanUtils.getProperty(value, firstFieldName);
            final Object secondObj = BeanUtils.getProperty(value, secondFieldName);
            final Object thirdObj = BeanUtils.getProperty(value, thirdFieldName);
            final String same = BeanUtils.getProperty(value, match);

            boolean valid = false;
            if(same != null && Boolean.getBoolean(same)){
                if("".equals(thirdObj)){
                    valid = firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj) ;
                }
                else{
                    valid = firstObj != null && firstObj.equals(secondObj) && firstObj.equals(thirdObj) ;   
                }
            }
            else{
                if("".equals(thirdObj)){
                    valid = firstObj == null && secondObj == null || firstObj != null && !firstObj.equals(secondObj) ;
                }
                else{
                    valid = firstObj != null && !(firstObj.equals(secondObj) && firstObj.equals(thirdObj)) ;   
                }
            }
            return valid ;
        }
        catch (final Exception ignore)
        {
            // ignore
        }
        return true;
    }
}

The piece I'm most interested in is the code that reads -

    if(match != null && !Boolean.getBoolean(match)){
        message = "password.error.theseValuesMustNotMatch";
    }

解决方案

Here's how I was able to do this -

@Override
public void initialize(FieldMatch constraintAnnotation)
{
    firstFieldName = constraintAnnotation.first();
    secondFieldName = constraintAnnotation.second();
    thirdFieldName = constraintAnnotation.third();
    match = constraintAnnotation.match();

    //set a message variable on initialization    
    if("true".equals(match)){
        message = constraintAnnotation.message();
    }
    else{
        message = "{password.error.threeQuestionsSameAnswer}";}
}

@Override
public boolean isValid(final Object value, final ConstraintValidatorContext context)
{
    Object firstObj = null;
    Object secondObj = null;
    Object thirdObj = null;

    //disable existing violation message
    context.disableDefaultConstraintViolation();
    //build new violation message and add it
    context.buildConstraintViolationWithTemplate(message).addConstraintViolation();

etc.........
}

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