get All Fields from a Class - Java Reflection

Java examples for Reflection:Field Get

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Description

get All Fields from a Class

Demo Code

/**/* w  w w  . ja v  a 2s  .co m*/
 * 
 * Funf: Open Sensing Framework
 * Copyright (C) 2010-2011 Nadav Aharony, Wei Pan, Alex Pentland.
 * Acknowledgments: Alan Gardner
 * Contact: nadav@media.mit.edu
 * 
 * This file is part of Funf.
 * 
 * Funf is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 * 
 * Funf is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with Funf. If not, see <http://www.gnu.org/licenses/>.
 * 
 */
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.util.List;

public class Main{
    public static void main(String[] argv) throws Exception{
        List fields = java.util.Arrays.asList("asdf","java2s.com");
        Class type = String.class;
        System.out.println(getAllFields(fields,type));
    }
    /**
     * @param fields
     * @param type
     * @return
     */
    public static List<Field> getAllFields(List<Field> fields, Class<?> type) {
        return getAllFieldsWithAnnotation(fields, type, null);
    }
    public static List<Field> getAllFieldsWithAnnotation(
            List<Field> fields, Class<?> type,
            Class<? extends Annotation> annotationType) {
        for (Field field : type.getDeclaredFields()) {
            if (annotationType == null
                    || field.getAnnotation(annotationType) != null) {
                fields.add(field);
            }
        }

        if (type.getSuperclass() != null) {
            fields = getAllFieldsWithAnnotation(fields,
                    type.getSuperclass(), annotationType);
        }

        return fields;
    }
}

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