Get Annotated Declared Fields : Annotation « Reflection « Java

1. Java
2. Reflection
3. Annotation

Get Annotated Declared Fields

    
//package com.kupal.skypeCommand.util;

import java.lang.reflect.Field;
import java.lang.annotation.Annotation;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

/**
 * @author Kupal 3kb
 */
public class ClassUtil {

    /**
     * Create new instance of specified class and type
     *
     * @param clazz of instance
     * @param <T> type of object
     * @return new Class instance
     */
    public static <T> T getInstance(Class<T> clazz) {
        T t = null;
        try {
            t = clazz.newInstance();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }

        return t;
    }

    /**
     * Retrieving fields list of specified class
     * If recursively is true, retrieving fields from all class hierarchy
     *
     * @param clazz where fields are searching
     * @param recursively param
     * @return list of fields
     */
    public static Field[] getDeclaredFields(Class clazz, boolean recursively) {
        List<Field> fields = new LinkedList<Field>();
        Field[] declaredFields = clazz.getDeclaredFields();
        Collections.addAll(fields, declaredFields);

        Class superClass = clazz.getSuperclass();

        if(superClass != null && recursively) {
            Field[] declaredFieldsOfSuper = getDeclaredFields(superClass, recursively);
            if(declaredFieldsOfSuper.length > 0)
                Collections.addAll(fields, declaredFieldsOfSuper);
        }

        return fields.toArray(new Field[fields.size()]);
    }

    /**
     * Retrieving fields list of specified class and which
     * are annotated by incoming annotation class
     * If recursively is true, retrieving fields from all class hierarchy
     *
     * @param clazz - where fields are searching
     * @param annotationClass - specified annotation class
     * @param recursively param
     * @return list of annotated fields
     */
    public static Field[] getAnnotatedDeclaredFields(Class clazz,
                                                     Class<? extends Annotation> annotationClass,
                                                     boolean recursively) {
        Field[] allFields = getDeclaredFields(clazz, recursively);
        List<Field> annotatedFields = new LinkedList<Field>();

        for (Field field : allFields) {
            if(field.isAnnotationPresent(annotationClass))
                annotatedFields.add(field);
        }

        return annotatedFields.toArray(new Field[annotatedFields.size()]);
    }
}

   
    
    
    
  

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