FieldUtils.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package org.apache.commons.lang3.reflect;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.ClassUtils;
import org.apache.commons.lang3.JavaVersion;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.SystemUtils;
import org.apache.commons.lang3.Validate;
/**
* Utilities for working with {@link Field}s by reflection. Adapted and refactored from the dormant [reflect] Commons
* sandbox component.
* <p>
* The ability is provided to break the scoping restrictions coded by the programmer. This can allow fields to be
* changed that shouldn't be. This facility should be used with care.
* </p>
* @since 2.5
*/
public class FieldUtils {
/**
* Gets all fields of the given class and its parents (if any).
*
* @param cls
* the {@link Class} to query
* @return an array of Fields (possibly empty).
* @throws NullPointerException
* if the class is {@code null}
* @since 3.2
*/
public static Field[] getAllFields(final Class<?> cls) {
return getAllFieldsList(cls).toArray(ArrayUtils.EMPTY_FIELD_ARRAY);
}
/**
* Gets all fields of the given class and its parents (if any).
*
* @param cls
* the {@link Class} to query
* @return a list of Fields (possibly empty).
* @throws NullPointerException
* if the class is {@code null}
* @since 3.2
*/
public static List<Field> getAllFieldsList(final Class<?> cls) {
Objects.requireNonNull(cls, "cls");
final List<Field> allFields = new ArrayList<>();
Class<?> currentClass = cls;
while (currentClass != null) {
final Field[] declaredFields = currentClass.getDeclaredFields();
Collections.addAll(allFields, declaredFields);
currentClass = currentClass.getSuperclass();
}
return allFields;
}
/**
* Gets an accessible {@link Field} by name respecting scope. Only the specified class will be considered.
*
* @param cls
* the {@link Class} to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @return the Field object
* @throws NullPointerException
* if the class is {@code null}
* @throws IllegalArgumentException
* if the field name is {@code null}, blank, or empty
*/
public static Field getDeclaredField(final Class<?> cls, final String fieldName) {
return getDeclaredField(cls, fieldName, false);
}
/**
* Gets an accessible {@link Field} by name, breaking scope if requested. Only the specified class will be
* considered.
*
* @param cls
* the {@link Class} to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @return the Field object
* @throws NullPointerException
* if the class is {@code null}
* @throws IllegalArgumentException
* if the field name is {@code null}, blank, or empty
*/
public static Field getDeclaredField(final Class<?> cls, final String fieldName, final boolean forceAccess) {
Objects.requireNonNull(cls, "cls");
Validate.isTrue(StringUtils.isNotBlank(fieldName), "The field name must not be blank/empty");
try {
// only consider the specified class by using getDeclaredField()
final Field field = cls.getDeclaredField(fieldName);
if (!MemberUtils.isAccessible(field)) {
if (!forceAccess) {
return null;
}
field.setAccessible(true);
}
return field;
} catch (final NoSuchFieldException ignored) {
// ignore
}
return null;
}
/**
* Gets an accessible {@link Field} by name respecting scope. Superclasses/interfaces will be considered.
*
* @param cls
* the {@link Class} to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @return the Field object
* @throws NullPointerException
* if the class is {@code null}
* @throws IllegalArgumentException
* if the field name is {@code null}, blank, or empty
*/
public static Field getField(final Class<?> cls, final String fieldName) {
return MemberUtils.setAccessibleWorkaround(getField(cls, fieldName, false));
}
/**
* Gets an accessible {@link Field} by name, breaking scope if requested. Superclasses/interfaces will be
* considered.
*
* @param cls
* the {@link Class} to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @return the Field object
* @throws NullPointerException if the class is {@code null}
* @throws IllegalArgumentException if the field name is blank or empty or is matched at multiple places
* in the inheritance hierarchy
*/
public static Field getField(final Class<?> cls, final String fieldName, final boolean forceAccess) {
Objects.requireNonNull(cls, "cls");
Validate.isTrue(StringUtils.isNotBlank(fieldName), "The field name must not be blank/empty");
// FIXME is this workaround still needed? lang requires Java 6
// Sun Java 1.3 has a bugged implementation of getField hence we write the
// code ourselves
// getField() will return the Field object with the declaring class
// set correctly to the class that declares the field. Thus requesting the
// field on a subclass will return the field from the superclass.
//
// priority order for lookup:
// searchclass private/protected/package/public
// superclass protected/package/public
// private/different package blocks access to further superclasses
// implementedinterface public
// check up the superclass hierarchy
for (Class<?> acls = cls; acls != null; acls = acls.getSuperclass()) {
try {
final Field field = acls.getDeclaredField(fieldName);
// getDeclaredField checks for non-public scopes as well
// and it returns accurate results
if (!MemberUtils.isPublic(field)) {
if (!forceAccess) {
continue;
}
field.setAccessible(true);
}
return field;
} catch (final NoSuchFieldException ignored) {
// ignore
}
}
// check the public interface case. This must be manually searched for
// incase there is a public supersuperclass field hidden by a private/package
// superclass field.
Field match = null;
for (final Class<?> class1 : ClassUtils.getAllInterfaces(cls)) {
try {
final Field test = class1.getField(fieldName);
Validate.isTrue(match == null, "Reference to field %s is ambiguous relative to %s"
+ "; a matching field exists on two or more implemented interfaces.", fieldName, cls);
match = test;
} catch (final NoSuchFieldException ignored) {
// ignore
}
}
return match;
}
/**
* Gets all fields of the given class and its parents (if any) that are annotated with the given annotation.
* @param cls
* the {@link Class} to query
* @param annotationCls
* the {@link Annotation} that must be present on a field to be matched
* @return a list of Fields (possibly empty).
* @throws NullPointerException
* if the class or annotation are {@code null}
* @since 3.4
*/
public static List<Field> getFieldsListWithAnnotation(final Class<?> cls, final Class<? extends Annotation> annotationCls) {
Objects.requireNonNull(annotationCls, "annotationCls");
return getAllFieldsList(cls).stream().filter(field -> field.getAnnotation(annotationCls) != null).collect(Collectors.toList());
}
/**
* Gets all fields of the given class and its parents (if any) that are annotated with the given annotation.
* @param cls
* the {@link Class} to query
* @param annotationCls
* the {@link Annotation} that must be present on a field to be matched
* @return an array of Fields (possibly empty).
* @throws NullPointerException
* if the class or annotation are {@code null}
* @since 3.4
*/
public static Field[] getFieldsWithAnnotation(final Class<?> cls, final Class<? extends Annotation> annotationCls) {
return getFieldsListWithAnnotation(cls, annotationCls).toArray(ArrayUtils.EMPTY_FIELD_ARRAY);
}
/**
* Reads the named {@code public} {@link Field}. Only the class of the specified object will be considered.
*
* @param target
* the object to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @return the value of the field
* @throws NullPointerException
* if {@code target} is {@code null}
* @throws IllegalArgumentException
* if {@code fieldName} is {@code null}, blank or empty, or could not be found
* @throws IllegalAccessException
* if the named field is not {@code public}
*/
public static Object readDeclaredField(final Object target, final String fieldName) throws IllegalAccessException {
return readDeclaredField(target, fieldName, false);
}
/**
* Gets a {@link Field} value by name. Only the class of the specified object will be considered.
*
* @param target
* the object to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match public fields.
* @return the Field object
* @throws NullPointerException
* if {@code target} is {@code null}
* @throws IllegalArgumentException
* if {@code fieldName} is {@code null}, blank or empty, or could not be found
* @throws IllegalAccessException
* if the field is not made accessible
*/
public static Object readDeclaredField(final Object target, final String fieldName, final boolean forceAccess) throws IllegalAccessException {
Objects.requireNonNull(target, "target");
final Class<?> cls = target.getClass();
final Field field = getDeclaredField(cls, fieldName, forceAccess);
Validate.isTrue(field != null, "Cannot locate declared field %s.%s", cls, fieldName);
// already forced access above, don't repeat it here:
return readField(field, target, false);
}
/**
* Gets the value of a {@code static} {@link Field} by name. The field must be {@code public}. Only the specified
* class will be considered.
*
* @param cls
* the {@link Class} to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @return the value of the field
* @throws NullPointerException
* if the class is {@code null}, or the field could not be found
* @throws IllegalArgumentException
* if the field name is {@code null}, blank, empty, or is not {@code static}
* @throws IllegalAccessException
* if the field is not accessible
*/
public static Object readDeclaredStaticField(final Class<?> cls, final String fieldName) throws IllegalAccessException {
return readDeclaredStaticField(cls, fieldName, false);
}
/**
* Gets the value of a {@code static} {@link Field} by name. Only the specified class will be considered.
*
* @param cls
* the {@link Class} to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @return the Field object
* @throws NullPointerException
* if the class is {@code null}, or the field could not be found
* @throws IllegalArgumentException
* if the field name is blank or empty, is not {@code static}
* @throws IllegalAccessException
* if the field is not made accessible
*/
public static Object readDeclaredStaticField(final Class<?> cls, final String fieldName, final boolean forceAccess) throws IllegalAccessException {
final Field field = getDeclaredField(cls, fieldName, forceAccess);
Validate.notNull(field, "Cannot locate declared field %s.%s", cls.getName(), fieldName);
// already forced access above, don't repeat it here:
return readStaticField(field, false);
}
/**
* Reads an accessible {@link Field}.
*
* @param field
* the field to use
* @param target
* the object to call on, may be {@code null} for {@code static} fields
* @return the field value
* @throws NullPointerException
* if the field is {@code null}
* @throws IllegalAccessException
* if the field is not accessible
*/
public static Object readField(final Field field, final Object target) throws IllegalAccessException {
return readField(field, target, false);
}
/**
* Reads a {@link Field}.
*
* @param field
* the field to use
* @param target
* the object to call on, may be {@code null} for {@code static} fields
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method.
* @return the field value
* @throws NullPointerException
* if the field is {@code null}
* @throws IllegalAccessException
* if the field is not made accessible
*/
public static Object readField(final Field field, final Object target, final boolean forceAccess) throws IllegalAccessException {
Objects.requireNonNull(field, "field");
if (forceAccess && !field.isAccessible()) {
field.setAccessible(true);
} else {
MemberUtils.setAccessibleWorkaround(field);
}
return field.get(target);
}
/**
* Reads the named {@code public} {@link Field}. Superclasses will be considered.
*
* @param target
* the object to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @return the value of the field
* @throws NullPointerException
* if the target is {@code null}
* @throws IllegalArgumentException
* if the field name is {@code null}, blank, empty, or could not be found
* @throws IllegalAccessException
* if the named field is not {@code public}
*/
public static Object readField(final Object target, final String fieldName) throws IllegalAccessException {
return readField(target, fieldName, false);
}
/**
* Reads the named {@link Field}. Superclasses will be considered.
*
* @param target
* the object to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @return the field value
* @throws NullPointerException
* if {@code target} is {@code null}
* @throws IllegalArgumentException
* if the field name is {@code null}, blank, empty, or could not be found
* @throws IllegalAccessException
* if the named field is not made accessible
*/
public static Object readField(final Object target, final String fieldName, final boolean forceAccess) throws IllegalAccessException {
Objects.requireNonNull(target, "target");
final Class<?> cls = target.getClass();
final Field field = getField(cls, fieldName, forceAccess);
Validate.isTrue(field != null, "Cannot locate field %s on %s", fieldName, cls);
// already forced access above, don't repeat it here:
return readField(field, target, false);
}
/**
* Reads the named {@code public static} {@link Field}. Superclasses will be considered.
*
* @param cls
* the {@link Class} to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @return the value of the field
* @throws NullPointerException
* if the class is {@code null}, or the field could not be found
* @throws IllegalArgumentException
* if the field name is {@code null}, blank or empty, or is not {@code static}
* @throws IllegalAccessException
* if the field is not accessible
*/
public static Object readStaticField(final Class<?> cls, final String fieldName) throws IllegalAccessException {
return readStaticField(cls, fieldName, false);
}
/**
* Reads the named {@code static} {@link Field}. Superclasses will be considered.
*
* @param cls
* the {@link Class} to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @return the Field object
* @throws NullPointerException
* if the class is {@code null}, or the field could not be found
* @throws IllegalArgumentException
* if the field name is {@code null}, blank or empty, or is not {@code static}
* @throws IllegalAccessException
* if the field is not made accessible
*/
public static Object readStaticField(final Class<?> cls, final String fieldName, final boolean forceAccess) throws IllegalAccessException {
final Field field = getField(cls, fieldName, forceAccess);
Validate.notNull(field, "Cannot locate field '%s' on %s", fieldName, cls);
// already forced access above, don't repeat it here:
return readStaticField(field, false);
}
/**
* Reads an accessible {@code static} {@link Field}.
*
* @param field
* to read
* @return the field value
* @throws NullPointerException
* if the field is {@code null}
* @throws IllegalArgumentException
* if the field is not {@code static}
* @throws IllegalAccessException
* if the field is not accessible
*/
public static Object readStaticField(final Field field) throws IllegalAccessException {
return readStaticField(field, false);
}
/**
* Reads a static {@link Field}.
*
* @param field
* to read
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method.
* @return the field value
* @throws NullPointerException
* if the field is {@code null}
* @throws IllegalArgumentException
* if the field is not {@code static}
* @throws IllegalAccessException
* if the field is not made accessible
*/
public static Object readStaticField(final Field field, final boolean forceAccess) throws IllegalAccessException {
Objects.requireNonNull(field, "field");
Validate.isTrue(MemberUtils.isStatic(field), "The field '%s' is not static", field.getName());
return readField(field, (Object) null, forceAccess);
}
/**
* Removes the final modifier from a {@link Field}.
*
* @param field
* to remove the final modifier
* @throws NullPointerException
* if the field is {@code null}
* @since 3.2
*/
public static void removeFinalModifier(final Field field) {
removeFinalModifier(field, true);
}
/**
* Removes the final modifier from a {@link Field}.
*
* @param field
* to remove the final modifier
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @throws NullPointerException
* if the field is {@code null}
* @deprecated As of Java 12, we can no longer drop the {@code final} modifier, thus
* rendering this method obsolete. The JDK discussion about this change can be found
* here: https://mail.openjdk.java.net/pipermail/core-libs-dev/2018-November/056486.html
* @since 3.3
*/
@Deprecated
public static void removeFinalModifier(final Field field, final boolean forceAccess) {
Objects.requireNonNull(field, "field");
try {
if (Modifier.isFinal(field.getModifiers())) {
// Do all JREs implement Field with a private ivar called "modifiers"?
final Field modifiersField = Field.class.getDeclaredField("modifiers");
final boolean doForceAccess = forceAccess && !modifiersField.isAccessible();
if (doForceAccess) {
modifiersField.setAccessible(true);
}
try {
modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);
} finally {
if (doForceAccess) {
modifiersField.setAccessible(false);
}
}
}
} catch (final NoSuchFieldException | IllegalAccessException e) {
if (SystemUtils.isJavaVersionAtLeast(JavaVersion.JAVA_12)) {
throw new UnsupportedOperationException(
"In java 12+ final cannot be removed.",
e
);
}
// else no exception is thrown because we can modify final.
}
}
/**
* Writes a {@code public} {@link Field}. Only the specified class will be considered.
*
* @param target
* the object to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @param value
* to set
* @throws NullPointerException
* if {@code target} is {@code null}
* @throws IllegalArgumentException
* if {@code fieldName} is {@code null}, blank or empty, or could not be found,
* or {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not made accessible
*/
public static void writeDeclaredField(final Object target, final String fieldName, final Object value) throws IllegalAccessException {
writeDeclaredField(target, fieldName, value, false);
}
/**
* Writes a {@code public} {@link Field}. Only the specified class will be considered.
*
* @param target
* the object to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @param value
* to set
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @throws IllegalArgumentException
* if {@code fieldName} is {@code null}, blank or empty, or could not be found,
* or {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not made accessible
*/
public static void writeDeclaredField(final Object target, final String fieldName, final Object value, final boolean forceAccess)
throws IllegalAccessException {
Objects.requireNonNull(target, "target");
final Class<?> cls = target.getClass();
final Field field = getDeclaredField(cls, fieldName, forceAccess);
Validate.isTrue(field != null, "Cannot locate declared field %s.%s", cls.getName(), fieldName);
// already forced access above, don't repeat it here:
writeField(field, target, value, false);
}
/**
* Writes a named {@code public static} {@link Field}. Only the specified class will be considered.
*
* @param cls
* {@link Class} on which the field is to be found
* @param fieldName
* to write
* @param value
* to set
* @throws NullPointerException
* if {@code cls} is {@code null} or the field cannot be located
* @throws IllegalArgumentException
* if the field name is {@code null}, blank, empty, not {@code static}, or {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not {@code public} or is {@code final}
*/
public static void writeDeclaredStaticField(final Class<?> cls, final String fieldName, final Object value) throws IllegalAccessException {
writeDeclaredStaticField(cls, fieldName, value, false);
}
/**
* Writes a named {@code static} {@link Field}. Only the specified class will be considered.
*
* @param cls
* {@link Class} on which the field is to be found
* @param fieldName
* to write
* @param value
* to set
* @param forceAccess
* whether to break scope restrictions using the {@code AccessibleObject#setAccessible(boolean)} method.
* {@code false} will only match {@code public} fields.
* @throws NullPointerException
* if {@code cls} is {@code null} or the field cannot be located
* @throws IllegalArgumentException
* if the field name is {@code null}, blank, empty, not {@code static}, or {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not made accessible or is {@code final}
*/
public static void writeDeclaredStaticField(final Class<?> cls, final String fieldName, final Object value, final boolean forceAccess)
throws IllegalAccessException {
final Field field = getDeclaredField(cls, fieldName, forceAccess);
Validate.notNull(field, "Cannot locate declared field %s.%s", cls.getName(), fieldName);
// already forced access above, don't repeat it here:
writeField(field, (Object) null, value, false);
}
/**
* Writes an accessible {@link Field}.
*
* @param field
* to write
* @param target
* the object to call on, may be {@code null} for {@code static} fields
* @param value
* to set
* @throws NullPointerException
* if the field is {@code null}
* @throws IllegalArgumentException
* if {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not accessible or is {@code final}
*/
public static void writeField(final Field field, final Object target, final Object value) throws IllegalAccessException {
writeField(field, target, value, false);
}
/**
* Writes a {@link Field}.
*
* @param field
* to write
* @param target
* the object to call on, may be {@code null} for {@code static} fields
* @param value
* to set
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @throws NullPointerException
* if the field is {@code null}
* @throws IllegalArgumentException
* if {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not made accessible or is {@code final}
*/
public static void writeField(final Field field, final Object target, final Object value, final boolean forceAccess)
throws IllegalAccessException {
Objects.requireNonNull(field, "field");
if (forceAccess && !field.isAccessible()) {
field.setAccessible(true);
} else {
MemberUtils.setAccessibleWorkaround(field);
}
field.set(target, value);
}
/**
* Writes a {@code public} {@link Field}. Superclasses will be considered.
*
* @param target
* the object to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @param value
* to set
* @throws NullPointerException
* if {@code target} is {@code null}
* @throws IllegalArgumentException
* if {@code fieldName} is {@code null}, blank, empty, or could not be found,
* or {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not accessible
*/
public static void writeField(final Object target, final String fieldName, final Object value) throws IllegalAccessException {
writeField(target, fieldName, value, false);
}
/**
* Writes a {@link Field}. Superclasses will be considered.
*
* @param target
* the object to reflect, must not be {@code null}
* @param fieldName
* the field name to obtain
* @param value
* to set
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @throws NullPointerException
* if {@code target} is {@code null}
* @throws IllegalArgumentException
* if {@code fieldName} is {@code null}, blank, empty, or could not be found,
* or {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not made accessible
*/
public static void writeField(final Object target, final String fieldName, final Object value, final boolean forceAccess)
throws IllegalAccessException {
Objects.requireNonNull(target, "target");
final Class<?> cls = target.getClass();
final Field field = getField(cls, fieldName, forceAccess);
Validate.isTrue(field != null, "Cannot locate declared field %s.%s", cls.getName(), fieldName);
// already forced access above, don't repeat it here:
writeField(field, target, value, false);
}
/**
* Writes a named {@code public static} {@link Field}. Superclasses will be considered.
*
* @param cls
* {@link Class} on which the field is to be found
* @param fieldName
* to write
* @param value
* to set
* @throws NullPointerException
* if {@code target} is {@code null}
* @throws IllegalArgumentException
* if {@code fieldName} is {@code null}, blank or empty, the field cannot be located or is
* not {@code static}, or {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not {@code public} or is {@code final}
*/
public static void writeStaticField(final Class<?> cls, final String fieldName, final Object value) throws IllegalAccessException {
writeStaticField(cls, fieldName, value, false);
}
/**
* Writes a named {@code static} {@link Field}. Superclasses will be considered.
*
* @param cls
* {@link Class} on which the field is to be found
* @param fieldName
* to write
* @param value
* to set
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @throws NullPointerException
* if {@code cls} is {@code null} or the field cannot be located
* @throws IllegalArgumentException
* if {@code fieldName} is {@code null}, blank or empty, the field not {@code static}, or {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not made accessible or is {@code final}
*/
public static void writeStaticField(final Class<?> cls, final String fieldName, final Object value, final boolean forceAccess)
throws IllegalAccessException {
final Field field = getField(cls, fieldName, forceAccess);
Validate.notNull(field, "Cannot locate field %s on %s", fieldName, cls);
// already forced access above, don't repeat it here:
writeStaticField(field, value, false);
}
/**
* Writes a {@code public static} {@link Field}.
*
* @param field
* to write
* @param value
* to set
* @throws NullPointerException
* if the field is {@code null}
* @throws IllegalArgumentException
* if the field is not {@code static}, or {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not {@code public} or is {@code final}
*/
public static void writeStaticField(final Field field, final Object value) throws IllegalAccessException {
writeStaticField(field, value, false);
}
/**
* Writes a static {@link Field}.
*
* @param field
* to write
* @param value
* to set
* @param forceAccess
* whether to break scope restrictions using the
* {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} method. {@code false} will only
* match {@code public} fields.
* @throws NullPointerException
* if the field is {@code null}
* @throws IllegalArgumentException
* if the field is not {@code static}, or {@code value} is not assignable
* @throws IllegalAccessException
* if the field is not made accessible or is {@code final}
*/
public static void writeStaticField(final Field field, final Object value, final boolean forceAccess) throws IllegalAccessException {
Objects.requireNonNull(field, "field");
Validate.isTrue(MemberUtils.isStatic(field), "The field %s.%s is not static", field.getDeclaringClass().getName(),
field.getName());
writeField(field, (Object) null, value, forceAccess);
}
/**
* {@link FieldUtils} instances should NOT be constructed in standard programming.
* <p>
* This constructor is {@code public} to permit tools that require a JavaBean instance to operate.
* </p>
*
* @deprecated TODO Make private in 4.0.
*/
@Deprecated
public FieldUtils() {
// empty
}
}