ELInterpreterTagSetters.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.jasper.optimizations;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.el.ELResolver;
import org.apache.jasper.JspCompilationContext;
import org.apache.jasper.compiler.ELInterpreter;
import org.apache.jasper.compiler.JspUtil;
import org.apache.jasper.compiler.Localizer;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
/**
* A non-specification compliant {@link ELInterpreter} that optimizes a subset
* of setters for tag attributes.
* <p>
* The cases optimized by this implementation are:
* <ul>
* <li>expressions that are solely a literal boolean</li>
* <li>expressions that are solely a constant string used (with coercion where
* necessary) with a setter that accepts:</li>
* <li><ul>
* <li>boolean / Boolean</li>
* <li>char / Character</li>
* <li>BigDecimal</li>
* <li>long / Long</li>
* <li>int / Integer</li>
* <li>short / Short</li>
* <li>byte / Byte</li>
* <li>double / Double</li>
* <li>float / Float</li>
* <li>BigInteger</li>
* <li>Enum</li>
* <li>String</li>
* </ul></li>
* </ul>
* The specification compliance issue is that it essentially skips the first
* three {@link ELResolver}s listed in section JSP.2.9 and effectively hard
* codes the use of the 4th {@link ELResolver} in that list.
*
* @see "https://bz.apache.org/bugzilla/show_bug.cgi?id=64872"
*/
public class ELInterpreterTagSetters implements ELInterpreter {
// Can't be static
private final Log log = LogFactory.getLog(ELInterpreterTagSetters.class);
private final Pattern PATTERN_BOOLEAN = Pattern.compile("[$][{]([\"']?)(true|false)\\1[}]");
private final Pattern PATTERN_STRING_CONSTANT = Pattern.compile("[$][{]([\"'])(\\w+)\\1[}]");
private final Pattern PATTERN_NUMERIC = Pattern.compile("[$][{]([\"'])([+-]?\\d+(\\.\\d+)?)\\1[}]");
@Override
public String interpreterCall(JspCompilationContext context,
boolean isTagFile, String expression,
Class<?> expectedType, String fnmapvar) {
String result = null;
// Boolean
if (Boolean.TYPE == expectedType) {
Matcher m = PATTERN_BOOLEAN.matcher(expression);
if (m.matches()) {
result = m.group(2);
}
} else if (Boolean.class == expectedType) {
Matcher m = PATTERN_BOOLEAN.matcher(expression);
if (m.matches()) {
if ("true".equals(m.group(2))) {
result = "Boolean.TRUE";
} else {
result = "Boolean.FALSE";
}
}
// Character
} else if (Character.TYPE == expectedType) {
Matcher m = PATTERN_STRING_CONSTANT.matcher(expression);
if (m.matches()) {
return "\'" + m.group(2).charAt(0) + "\'";
}
} else if (Character.class == expectedType) {
Matcher m = PATTERN_STRING_CONSTANT.matcher(expression);
if (m.matches()) {
return "Character.valueOf(\'" + m.group(2).charAt(0) + "\')";
}
// Numeric - BigDecimal
} else if (BigDecimal.class == expectedType) {
Matcher m = PATTERN_NUMERIC.matcher(expression);
if (m.matches()) {
try {
@SuppressWarnings("unused")
BigDecimal unused = new BigDecimal(m.group(2));
result = "new java.math.BigDecimal(\"" + m.group(2) + "\")";
} catch (NumberFormatException e) {
log.debug(Localizer.getMessage("jsp.error.typeConversion", m.group(2), "BigDecimal"), e);
// Continue and resolve the value at runtime
}
}
// Numeric - long/Long
} else if (Long.TYPE == expectedType || Long.class == expectedType) {
Matcher m = PATTERN_NUMERIC.matcher(expression);
if (m.matches()) {
try {
@SuppressWarnings("unused")
Long unused = Long.valueOf(m.group(2));
if (expectedType.isPrimitive()) {
// Long requires explicit declaration as a long literal
result = m.group(2) + "L";
} else {
result = "Long.valueOf(\"" + m.group(2) + "\")";
}
} catch (NumberFormatException e) {
log.debug(Localizer.getMessage("jsp.error.typeConversion", m.group(2), "Long"), e);
// Continue and resolve the value at runtime
}
}
// Numeric - int/Integer
} else if (Integer.TYPE == expectedType || Integer.class == expectedType) {
Matcher m = PATTERN_NUMERIC.matcher(expression);
if (m.matches()) {
try {
@SuppressWarnings("unused")
Integer unused = Integer.valueOf(m.group(2));
if (expectedType.isPrimitive()) {
result = m.group(2);
} else {
result = "Integer.valueOf(\"" + m.group(2) + "\")";
}
} catch (NumberFormatException e) {
log.debug(Localizer.getMessage("jsp.error.typeConversion", m.group(2), "Integer"), e);
// Continue and resolve the value at runtime
}
}
// Numeric - short/Short
} else if (Short.TYPE == expectedType || Short.class == expectedType) {
Matcher m = PATTERN_NUMERIC.matcher(expression);
if (m.matches()) {
try {
@SuppressWarnings("unused")
Short unused = Short.valueOf(m.group(2));
if (expectedType.isPrimitive()) {
// short requires a downcast
result = "(short) " + m.group(2);
} else {
result = "Short.valueOf(\"" + m.group(2) + "\")";
}
} catch (NumberFormatException e) {
log.debug(Localizer.getMessage("jsp.error.typeConversion", m.group(2), "Short"), e);
// Continue and resolve the value at runtime
}
}
// Numeric - byte/Byte
} else if (Byte.TYPE == expectedType || Byte.class == expectedType) {
Matcher m = PATTERN_NUMERIC.matcher(expression);
if (m.matches()) {
try {
@SuppressWarnings("unused")
Byte unused = Byte.valueOf(m.group(2));
if (expectedType.isPrimitive()) {
// byte requires a downcast
result = "(byte) " + m.group(2);
} else {
result = "Byte.valueOf(\"" + m.group(2) + "\")";
}
} catch (NumberFormatException e) {
log.debug(Localizer.getMessage("jsp.error.typeConversion", m.group(2), "Byte"), e);
// Continue and resolve the value at runtime
}
}
// Numeric - double/Double
} else if (Double.TYPE == expectedType || Double.class == expectedType) {
Matcher m = PATTERN_NUMERIC.matcher(expression);
if (m.matches()) {
try {
@SuppressWarnings("unused")
Double unused = Double.valueOf(m.group(2));
if (expectedType.isPrimitive()) {
result = m.group(2);
} else {
result = "Double.valueOf(\"" + m.group(2) + "\")";
}
} catch (NumberFormatException e) {
log.debug(Localizer.getMessage("jsp.error.typeConversion", m.group(2), "Double"), e);
// Continue and resolve the value at runtime
}
}
// Numeric - float/Float
} else if (Float.TYPE == expectedType || Float.class == expectedType) {
Matcher m = PATTERN_NUMERIC.matcher(expression);
if (m.matches()) {
try {
@SuppressWarnings("unused")
Float unused = Float.valueOf(m.group(2));
if (expectedType.isPrimitive()) {
// Float requires explicit declaration as a float literal
result = m.group(2) + "f";
} else {
result = "Float.valueOf(\"" + m.group(2) + "\")";
}
} catch (NumberFormatException e) {
log.debug(Localizer.getMessage("jsp.error.typeConversion", m.group(2), "Float"), e);
// Continue and resolve the value at runtime
}
}
// Numeric - BigInteger
} else if (BigInteger.class == expectedType) {
Matcher m = PATTERN_NUMERIC.matcher(expression);
if (m.matches()) {
try {
@SuppressWarnings("unused")
BigInteger unused = new BigInteger(m.group(2));
result = "new java.math.BigInteger(\"" + m.group(2) + "\")";
} catch (NumberFormatException e) {
log.debug(Localizer.getMessage("jsp.error.typeConversion", m.group(2), "BigInteger"), e);
// Continue and resolve the value at runtime
}
}
// Enum
} else if (expectedType.isEnum()){
Matcher m = PATTERN_STRING_CONSTANT.matcher(expression);
if (m.matches()) {
try {
@SuppressWarnings({ "unchecked", "rawtypes" })
Enum<?> enumValue = Enum.valueOf((Class<? extends Enum>) expectedType, m.group(2));
result = expectedType.getName() + "." + enumValue.name();
} catch (IllegalArgumentException iae) {
log.debug(Localizer.getMessage("jsp.error.typeConversion", m.group(2), "Enum[" + expectedType.getName() + "]"), iae);
// Continue and resolve the value at runtime
}
}
// String
} else if (String.class == expectedType) {
Matcher m = PATTERN_STRING_CONSTANT.matcher(expression);
if (m.matches()) {
result = "\"" + m.group(2) + "\"";
}
}
if (result == null) {
result = JspUtil.interpreterCall(isTagFile, expression, expectedType,
fnmapvar);
}
if (log.isTraceEnabled()) {
log.trace("Expression [" + expression + "], type [" + expectedType.getName() + "], returns [" + result + "]");
}
return result;
}
}