nl.nn.xmldecoder.finder.FieldFinder Maven / Gradle / Ivy
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package nl.nn.xmldecoder.finder;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
/**
* This utility class provides {@code static} methods
* to find a public field with specified name
* in specified class.
*
* @since 1.7
*
* @author Sergey A. Malenkov
*/
public final class FieldFinder {
/**
* Finds public field (static or non-static)
* that is declared in public class.
*
* @param type the class that can have field
* @param name the name of field to find
* @return object that represents found field
* @throws NoSuchFieldException if field is not found
* @see Class#getField
*/
public static Field findField(Class type, String name) throws NoSuchFieldException {
if (name == null) {
throw new IllegalArgumentException("Field name is not set");
}
Field field = type.getField(name);
if (!Modifier.isPublic(field.getModifiers())) {
throw new NoSuchFieldException("Field '" + name + "' is not public");
}
if (!Modifier.isPublic(field.getDeclaringClass().getModifiers())) {
throw new NoSuchFieldException("Field '" + name + "' is not accessible");
}
return field;
}
/**
* Finds public non-static field
* that is declared in public class.
*
* @param type the class that can have field
* @param name the name of field to find
* @return object that represents found field
* @throws NoSuchFieldException if field is not found
* @see Class#getField
*/
public static Field findInstanceField(Class type, String name) throws NoSuchFieldException {
Field field = findField(type, name);
if (Modifier.isStatic(field.getModifiers())) {
throw new NoSuchFieldException("Field '" + name + "' is static");
}
return field;
}
/**
* Finds public static field
* that is declared in public class.
*
* @param type the class that can have field
* @param name the name of field to find
* @return object that represents found field
* @throws NoSuchFieldException if field is not found
* @see Class#getField
*/
public static Field findStaticField(Class type, String name) throws NoSuchFieldException {
Field field = findField(type, name);
if (!Modifier.isStatic(field.getModifiers())) {
throw new NoSuchFieldException("Field '" + name + "' is not static");
}
return field;
}
/**
* Disable instantiation.
*/
private FieldFinder() {
}
}