org.apache.taglibs.standard.lang.jstl.ArraySuffix Maven / Gradle / Ivy
/*
* 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.taglibs.standard.lang.jstl;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.util.List;
import java.util.Map;
/**
* Represents an operator that obtains a Map entry, an indexed
* value, a property value, or an indexed property value of an object.
* The following are the rules for evaluating this operator:
*
* Evaluating a[b] (assuming a.b == a["b"])
* a is null
* return null
* b is null
* return null
* a is Map
* !a.containsKey (b)
* return null
* a.get(b) == null
* return null
* otherwise
* return a.get(b)
* a is List or array
* coerce b to int (using coercion rules)
* coercion couldn't be performed
* error
* a.get(b) or Array.get(a, b) throws ArrayIndexOutOfBoundsException or IndexOutOfBoundsException
* return null
* a.get(b) or Array.get(a, b) throws other exception
* error
* return a.get(b) or Array.get(a, b)
*
* coerce b to String
* b is a readable property of a
* getter throws an exception
* error
* otherwise
* return result of getter call
*
* otherwise
* error
*
*
* @author Nathan Abramson - Art Technology Group
* @author Shawn Bayern
*/
public class ArraySuffix
extends ValueSuffix {
//-------------------------------------
// Constants
//-------------------------------------
// Zero-argument array
static Object[] sNoArgs = new Object[0];
//-------------------------------------
// Properties
//-------------------------------------
// property index
Expression mIndex;
public Expression getIndex() {
return mIndex;
}
public void setIndex(Expression pIndex) {
mIndex = pIndex;
}
//-------------------------------------
/**
* Constructor
*/
public ArraySuffix(Expression pIndex) {
mIndex = pIndex;
}
//-------------------------------------
/**
* Gets the value of the index
*/
Object evaluateIndex(Object pContext,
VariableResolver pResolver,
Map functions,
String defaultPrefix,
Logger pLogger)
throws ELException {
return mIndex.evaluate(pContext, pResolver, functions, defaultPrefix,
pLogger);
}
//-------------------------------------
/**
* Returns the operator symbol
*/
String getOperatorSymbol() {
return "[]";
}
//-------------------------------------
// ValueSuffix methods
//-------------------------------------
/**
* Returns the expression in the expression language syntax
*/
public String getExpressionString() {
return "[" + mIndex.getExpressionString() + "]";
}
//-------------------------------------
/**
* Evaluates the expression in the given context, operating on the
* given value.
*/
public Object evaluate(Object pValue,
Object pContext,
VariableResolver pResolver,
Map functions,
String defaultPrefix,
Logger pLogger)
throws ELException {
Object indexVal;
String indexStr;
BeanInfoProperty property;
BeanInfoIndexedProperty ixproperty;
// Check for null value
if (pValue == null) {
if (pLogger.isLoggingWarning()) {
pLogger.logWarning
(Constants.CANT_GET_INDEXED_VALUE_OF_NULL,
getOperatorSymbol());
}
return null;
}
// Evaluate the index
else if ((indexVal = evaluateIndex(pContext, pResolver,
functions, defaultPrefix, pLogger)) ==
null) {
if (pLogger.isLoggingWarning()) {
pLogger.logWarning
(Constants.CANT_GET_NULL_INDEX,
getOperatorSymbol());
}
return null;
}
// See if it's a Map
else if (pValue instanceof Map) {
Map val = (Map) pValue;
return val.get(indexVal);
}
// See if it's a List or array
else if (pValue instanceof List ||
pValue.getClass().isArray()) {
Integer indexObj = Coercions.coerceToInteger(indexVal, pLogger);
if (indexObj == null) {
if (pLogger.isLoggingError()) {
pLogger.logError
(Constants.BAD_INDEX_VALUE,
getOperatorSymbol(),
indexVal.getClass().getName());
}
return null;
} else if (pValue instanceof List) {
try {
return ((List) pValue).get(indexObj.intValue());
}
catch (ArrayIndexOutOfBoundsException exc) {
if (pLogger.isLoggingWarning()) {
pLogger.logWarning
(Constants.EXCEPTION_ACCESSING_LIST,
exc,
indexObj);
}
return null;
}
catch (IndexOutOfBoundsException exc) {
if (pLogger.isLoggingWarning()) {
pLogger.logWarning
(Constants.EXCEPTION_ACCESSING_LIST,
exc,
indexObj);
}
return null;
}
catch (Exception exc) {
if (pLogger.isLoggingError()) {
pLogger.logError
(Constants.EXCEPTION_ACCESSING_LIST,
exc,
indexObj);
}
return null;
}
} else {
try {
return Array.get(pValue, indexObj.intValue());
}
catch (ArrayIndexOutOfBoundsException exc) {
if (pLogger.isLoggingWarning()) {
pLogger.logWarning
(Constants.EXCEPTION_ACCESSING_ARRAY,
exc,
indexObj);
}
return null;
}
catch (IndexOutOfBoundsException exc) {
if (pLogger.isLoggingWarning()) {
pLogger.logWarning
(Constants.EXCEPTION_ACCESSING_ARRAY,
exc,
indexObj);
}
return null;
}
catch (Exception exc) {
if (pLogger.isLoggingError()) {
pLogger.logError
(Constants.EXCEPTION_ACCESSING_ARRAY,
exc,
indexObj);
}
return null;
}
}
}
// Coerce to a String for property access
else if ((indexStr = Coercions.coerceToString(indexVal, pLogger)) ==
null) {
return null;
}
// Look for a JavaBean property
else if ((property = BeanInfoManager.getBeanInfoProperty
(pValue.getClass(),
indexStr,
pLogger)) != null &&
property.getReadMethod() != null) {
try {
return property.getReadMethod().invoke(pValue, sNoArgs);
}
catch (InvocationTargetException exc) {
if (pLogger.isLoggingError()) {
pLogger.logError
(Constants.ERROR_GETTING_PROPERTY,
exc.getTargetException(),
indexStr,
pValue.getClass().getName());
}
return null;
}
catch (Exception exc) {
if (pLogger.isLoggingError()) {
pLogger.logError
(Constants.ERROR_GETTING_PROPERTY,
exc,
indexStr,
pValue.getClass().getName());
}
return null;
}
} else {
if (pLogger.isLoggingError()) {
pLogger.logError
(Constants.CANT_FIND_INDEX,
indexVal,
pValue.getClass().getName(),
getOperatorSymbol());
}
return null;
}
}
//-------------------------------------
}