CODEWITHSUNDEEP
javareflectionfield
gstackoverflow
gstackoverflow

Reputation: 36984

reflection. How to know sibling field value?

I have following class:

class CampaignBeanDto {

    Date startDate;

    @MyAnnotation
    Date endDate;

}

I need the reference to field endDate

I should know which value has value startDate for same instance

Upvotes: 1

Views: 137

Answers (2)

Rahul Thachilath
Rahul Thachilath

Reputation: 363

The following code will get all the fields from the instance provided. It will scan the annotations. will get all the value of the fields having your custom annotation

Field[] fields = instance.getClass().getDeclaredFields();
if(instance.getAnnotation(MyAnnotation.class) != null){
        for (Field field : fields) {
            boolean access = field.isAccessible();
            field.setAccessible(true);

            //getting value
            System.out.println(field.get(instance));

            field.setAccessible(access);

        }
}

Upvotes: 0

Jean-François Savard
Jean-François Savard

Reputation: 21004

Assuming you wrote @MyAnnotation on top of endDate I believe what you want is to retrieve a field which is annotated with some annotation.

You can achieve this that way :

for(Field f : CampaignBeanDto.class.getFields())
{
    if(f.getAnnotation(MyAnnotation.class) != null)
    {
         //this is the field you are searching
    }
}

If the field is always named endDate then you can simply do :

for(Field f : CampaignBeanDto.class.getFields())
{
    if(f.getName().equals("endDate"))
    {
         //this is the field you are searching
    }
}

Upvotes: 1

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