Java Reflection Field Find findField(final Class clazz, final String name, final Class type)

Description

Attempt to find a Field field on the supplied Class with the supplied name and/or Class type .

License

Apache License

Parameter

Parameter	Description
clazz	The class to introspect
name	The name of the field (may be <code>null</code> if type is specified)
type	The type of the field (may be <code>null</code> if name is specified)

Return

The corresponding Field object

Declaration

public static Field findField(final Class<?> clazz, final String name, final Class<?> type) 

Method Source Code

//package com.java2s;
/*/*from  w  w  w . j  a  va 2 s.c  om*/
 * Copyright (C) 2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.lang.reflect.Field;

public class Main {
    /**
     * Attempt to find a {@link Field field} on the supplied {@link Class} with
     * the supplied <code>name</code> and/or {@link Class type}. Searches all
     * superclasses up to {@link Object}.
     *
     * @param clazz The class to introspect
     * @param name The name of the field (may be <code>null</code> if type is specified)
     * @param type The type of the field (may be <code>null</code> if name is specified)
     * @return The corresponding Field object
     */
    public static Field findField(final Class<?> clazz, final String name, final Class<?> type) {
        if (clazz == null) {
            throw new IllegalArgumentException("Class must not be null");
        }
        if (name == null && type == null) {
            throw new IllegalArgumentException("Either name or type of the field must be specified.");
        }
        Class<?> searchType = clazz;
        while (!Object.class.equals(searchType) && searchType != null) {
            Field[] fields = searchType.getDeclaredFields();
            for (Field field : fields) {
                if ((name == null || name.equals(field.getName()))
                        && (type == null || type.equals(field.getType()))) {
                    return field;
                }
            }
            searchType = searchType.getSuperclass();
        }
        throw new IllegalArgumentException(
                "Unable to find " + (type != null ? type.getName() : "") + " " + (name != null ? name : "") + ".");
    }
}

Related

1. findField(Class type, Class annotationClass)
2. findField(Class type, String fieldName)
3. findField(final Class aClass, final String fieldName)
4. findField(final Class clazz, final String name)
5. findField(final Class clazz, final String name)
6. findField(final Class cls, final String fieldName)
7. findField(final Class currentClass, final String fieldName)
8. findField(final Class declaringClass, final String fieldName)
9. findField(final Class klaz, final String fieldName)