find pojo fields by annotation name

field annotation
java annotation set field value
java change field annotation value runtime
java field annotation
java get field value
java get annotation value
use of custom annotation in java

This question already has an answer here:

You can do it with java reflection

for(Field field : BigcommerceNewsletterSubscriberData.class.getDeclaredFields()){
  Annotation[] annotations = field.getDeclaredAnnotationsByType(DataTableHeader.class);
  if (annotations.length > 0)
    System.out.println(field.getName());
}

Just filter fields, that have annotation you want.

Java Reflection - Annotations, Here is an example of a field with annotations: public class TheClass { @MyAnnotation(name="someName", value = "Hello How can I, using reflection, get the primary key column name from my POJO, defined with the javax.persistence.Id annotation? I'd have to find the @Id and then get the name property of the @Column annotation

We can use Class#getDeclaredFields() to get all fields as Field[]. With Field#getAnnotations(), we can get all annotations of one specific field as Annotation[].

With the help of these two methods, the problem is solvable. Below is a sample implementation using Java 8 Streams and Predicates.

List<Field> allFields = 
    Arrays.asList(BigcommerceNewsletterSubscriberData.class.getFields());
Predicate<Field> isAnnotated = 
    field -> Arrays.asList(field.getAnnotations()).contains(DataTableHeader.class);
List<Field> annotatedFields = allFields.stream()
        .filter(isAnnotated)
        .collect(Collectors.toList());

Please keep in mind though that Collectors.toList() does not guarantee that the returned List is mutable.

Java Reflection - Fields, This text explains how to introspect fields of classes, and get/set them at Obtaining Field Objects; Field Name; Field Type; Getting and Setting Allows for an alternative document key name when converting the POJO field to BSON. Also, allows a field to turn on using a discriminator when storing a POJO value. Annotations can be applied to read and / or write contexts by configuring the getter / setter methods. Any annotations applied to a field are applied to both read and write contexts.

You can also use the reflections library that provides a set of utilities for doing reflections in Java. To obtain a list of fields that contains a certain annotations, you can try this :

Reflections reflections = new Reflections("my.project");
Set<Field> fields = reflections.getFieldsAnnotatedWith(DataTableHeader .class);

If you are using maven, try add this to your pom dependencies :

<dependency>
   <groupId>org.reflections</groupId>
   <artifactId>reflections</artifactId>
    <version>0.9.11</version>
</dependency>

FieldUtils (Apache Commons Lang 3.10 API), Gets all fields of the given class and its parents (if any) that are annotated with is null , or the field name is blank or empty, is not static , or could not be found Entity (JPA Annotated POJO) How to annotate and transform your POJO to a JPA Entity Object. How to create a JPA Entity from a data-base table definition; How to create a data-base table from a JPA Entity; Do I annotate the field or property accessors (Field vs. Property Access) How to implement and handle data-base ID Generation (Primary Key IDs)

Creating Annotations in Java, For example, it is not difficult to find Java source code that includes the @Override For our JSON serializer, we will create a field annotation that allows a In summary, we created a public, single-element annotation named The @JsonIgnore annotation marks a field in a POJO to be ignored by Jackson during serialization and deserialization. Jackson ignores the field in both JSON serialization and deserialization. An example of Java class that uses the @JsonIgnore annotation is this.

Project Lombok: Clean, Concise Java Code, Add Lombok to your project and get rid of most of your boilerplate code. a plain old Java object (POJO), a Java class with several private fields that will Lombok can take care of generating these methods if a field is annotated with If you're using Lombok, you simply change the field name and move on with your life. In this quick tutorial, I show you how to change the name of a field to map to another JSON property on serialization. Jackson library provides @JsonProperty annotation that is used to change the property name in serialized JSON.

@Value, @Value is the immutable variant of @Data ; all fields are made private and final by default, access level on a field, or by using the @NonFinal or @PackagePrivate annotations. public ValueExample(String name, int age, double score, String[] tags) { See Getter/Setter documentation's small print for more information. Field Name. Once you have obtained a Field instance, you can get its field name using the Field.getName() method, like this: Field field = //obtain field object String fieldName = field.getName(); Field Type. You can determine the field type (String, int etc.) of a field using the Field.getType() method:

Comments

I want list of fields which contains @DataTableHeader annotation will it return list of fields? i am not getting perfactly so if you can clearify how it will return then please....
edited comment. Please check it
ok thank you i'll cheack it
@HardikSiroya please mark this answer as resolution after you test it