ArrayELResolver.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 jakarta.el;
- import java.beans.FeatureDescriptor;
- import java.lang.reflect.Array;
- import java.util.Iterator;
- import java.util.Objects;
- /**
- * Standard ELResolver for working with arrays.
- */
- public class ArrayELResolver extends ELResolver {
- private final boolean readOnly;
- /**
- * Creates a writable instance of the standard array resolver.
- */
- public ArrayELResolver() {
- this.readOnly = false;
- }
- /**
- * Creates an instance of the standard array resolver.
- *
- * @param readOnly {@code true} if the created instance should be read-only otherwise false.
- */
- public ArrayELResolver(boolean readOnly) {
- this.readOnly = readOnly;
- }
- @Override
- public Class<?> getType(ELContext context, Object base, Object property) {
- Objects.requireNonNull(context);
- if (base != null && base.getClass().isArray()) {
- context.setPropertyResolved(base, property);
- try {
- int idx = coerce(property);
- checkBounds(base, idx);
- } catch (IllegalArgumentException e) {
- // ignore
- }
- /*
- * The resolver may have been created in read-only mode but the array and its elements will always be
- * read-write.
- */
- if (readOnly) {
- return null;
- }
- return base.getClass().getComponentType();
- }
- return null;
- }
- @Override
- public Object getValue(ELContext context, Object base, Object property) {
- Objects.requireNonNull(context);
- if (base != null && base.getClass().isArray()) {
- context.setPropertyResolved(base, property);
- int idx = coerce(property);
- if (idx < 0 || idx >= Array.getLength(base)) {
- return null;
- }
- return Array.get(base, idx);
- }
- return null;
- }
- @Override
- public void setValue(ELContext context, Object base, Object property, Object value) {
- Objects.requireNonNull(context);
- if (base != null && base.getClass().isArray()) {
- context.setPropertyResolved(base, property);
- if (this.readOnly) {
- throw new PropertyNotWritableException(
- Util.message(context, "resolverNotWritable", base.getClass().getName()));
- }
- int idx = coerce(property);
- checkBounds(base, idx);
- if (value != null && !Util.isAssignableFrom(value.getClass(), base.getClass().getComponentType())) {
- throw new ClassCastException(Util.message(context, "objectNotAssignable", value.getClass().getName(),
- base.getClass().getComponentType().getName()));
- }
- Array.set(base, idx, value);
- }
- }
- @Override
- public boolean isReadOnly(ELContext context, Object base, Object property) {
- Objects.requireNonNull(context);
- if (base != null && base.getClass().isArray()) {
- context.setPropertyResolved(base, property);
- try {
- int idx = coerce(property);
- checkBounds(base, idx);
- } catch (IllegalArgumentException e) {
- // ignore
- }
- }
- return this.readOnly;
- }
- @Deprecated(forRemoval = true, since = "EL 5.0")
- @Override
- public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base) {
- return null;
- }
- @Override
- public Class<?> getCommonPropertyType(ELContext context, Object base) {
- if (base != null && base.getClass().isArray()) {
- return Integer.class;
- }
- return null;
- }
- private static void checkBounds(Object base, int idx) {
- if (idx < 0 || idx >= Array.getLength(base)) {
- throw new PropertyNotFoundException(new ArrayIndexOutOfBoundsException(idx).getMessage());
- }
- }
- private static int coerce(Object property) {
- if (property instanceof Number) {
- return ((Number) property).intValue();
- }
- if (property instanceof Character) {
- return ((Character) property).charValue();
- }
- if (property instanceof Boolean) {
- return ((Boolean) property).booleanValue() ? 1 : 0;
- }
- if (property instanceof String) {
- return Integer.parseInt((String) property);
- }
- throw new IllegalArgumentException(property != null ? property.toString() : "null");
- }
- }