/*
* 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 javax.el;
import java.beans.FeatureDescriptor;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
public class ListELResolver extends ELResolver {
private final boolean readOnly;
private final static Class UNMODIFIABLE = Collections.unmodifiableList(
new ArrayList()).getClass();
public ListELResolver() {
this.readOnly = false;
}
public ListELResolver(boolean readOnly) {
this.readOnly = readOnly;
}
public Object getValue(ELContext context, Object base, Object property)
throws NullPointerException, PropertyNotFoundException, ELException {
if (context == null) {
throw new NullPointerException();
}
if (base instanceof List) {
context.setPropertyResolved(true);
List list = (List) base;
int idx = coerce(property);
if (idx < 0 || idx >= list.size()) {
return null;
}
return list.get(idx);
}
return null;
}
public Class<?> getType(ELContext context, Object base, Object property)
throws NullPointerException, PropertyNotFoundException, ELException {
if (context == null) {
throw new NullPointerException();
}
if (base instanceof List) {
context.setPropertyResolved(true);
List list = (List) base;
int idx = coerce(property);
if (idx < 0 || idx >= list.size()) {
throw new PropertyNotFoundException(
new ArrayIndexOutOfBoundsException(idx).getMessage());
}
return Object.class;
}
return null;
}
public void setValue(ELContext context, Object base, Object property,
Object value) throws NullPointerException,
PropertyNotFoundException, PropertyNotWritableException,
ELException {
if (context == null) {
throw new NullPointerException();
}
if (base instanceof List) {
context.setPropertyResolved(true);
List list = (List) base;
if (this.readOnly) {
throw new PropertyNotWritableException(message(context,
"resolverNotWriteable", new Object[] { base.getClass()
.getName() }));
}
int idx = coerce(property);
try {
list.set(idx, value);
} catch (UnsupportedOperationException e) {
throw new PropertyNotWritableException(e);
} catch (IndexOutOfBoundsException e) {
throw new PropertyNotFoundException(e);
}
}
}
public boolean isReadOnly(ELContext context, Object base, Object property)
throws NullPointerException, PropertyNotFoundException, ELException {
if (context == null) {
throw new NullPointerException();
}
if (base instanceof List) {
context.setPropertyResolved(true);
List list = (List) base;
int idx = coerce(property);
if (idx < 0 || idx >= list.size()) {
throw new PropertyNotFoundException(
new ArrayIndexOutOfBoundsException(idx).getMessage());
}
return this.readOnly || UNMODIFIABLE.equals(list.getClass());
}
return this.readOnly;
}
public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base) {
if (base instanceof List) {
FeatureDescriptor[] descs = new FeatureDescriptor[((List) base).size()];
for (int i = 0; i < descs.length; i++) {
descs[i] = new FeatureDescriptor();
descs[i].setDisplayName("["+i+"]");
descs[i].setExpert(false);
descs[i].setHidden(false);
descs[i].setName(""+i);
descs[i].setPreferred(true);
descs[i].setValue(RESOLVABLE_AT_DESIGN_TIME, Boolean.FALSE);
descs[i].setValue(TYPE, Integer.class);
}
return Arrays.asList(descs).iterator();
}
return null;
}
public Class<?> getCommonPropertyType(ELContext context, Object base) {
if (base != null && base instanceof List) {
return Integer.class;
}
return null;
}
private final 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");
}
}