org.apache.activemq.artemis.selector.filter.ConstantExpression 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.activemq.artemis.selector.filter;
import java.math.BigDecimal;
/**
* Represents a constant expression
*
* @version $Revision: 1.2 $
*/
public class ConstantExpression implements Expression {
static class BooleanConstantExpression extends ConstantExpression implements BooleanExpression {
BooleanConstantExpression(Object value) {
super(value);
}
@Override
public boolean matches(Filterable message) throws FilterException {
Object object = evaluate(message);
return object != null && object == Boolean.TRUE;
}
}
public static final BooleanConstantExpression NULL = new BooleanConstantExpression(null);
public static final BooleanConstantExpression TRUE = new BooleanConstantExpression(Boolean.TRUE);
public static final BooleanConstantExpression FALSE = new BooleanConstantExpression(Boolean.FALSE);
private Object value;
public ConstantExpression(Object value) {
this.value = value;
}
public static ConstantExpression createFromDecimal(String text) {
// Strip off the 'l' or 'L' if needed.
if (text.endsWith("l") || text.endsWith("L")) {
text = text.substring(0, text.length() - 1);
}
Number value;
try {
value = new Long(text);
} catch (NumberFormatException e) {
// The number may be too big to fit in a long.
value = new BigDecimal(text);
}
long l = value.longValue();
if (Integer.MIN_VALUE <= l && l <= Integer.MAX_VALUE) {
value = Integer.valueOf(value.intValue());
}
return new ConstantExpression(value);
}
public static ConstantExpression createFromHex(String text) {
Number value = Long.valueOf(Long.parseLong(text.substring(2), 16));
long l = value.longValue();
if (Integer.MIN_VALUE <= l && l <= Integer.MAX_VALUE) {
value = Integer.valueOf(value.intValue());
}
return new ConstantExpression(value);
}
public static ConstantExpression createFromOctal(String text) {
Number value = Long.valueOf(Long.parseLong(text, 8));
long l = value.longValue();
if (Integer.MIN_VALUE <= l && l <= Integer.MAX_VALUE) {
value = Integer.valueOf(value.intValue());
}
return new ConstantExpression(value);
}
public static ConstantExpression createFloat(String text) {
Number value = new Double(text);
return new ConstantExpression(value);
}
@Override
public Object evaluate(Filterable message) throws FilterException {
return value;
}
public Object getValue() {
return value;
}
/**
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
if (value == null) {
return "NULL";
}
if (value instanceof Boolean) {
return ((Boolean) value).booleanValue() ? "TRUE" : "FALSE";
}
if (value instanceof String) {
return encodeString((String) value);
}
return value.toString();
}
/**
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
return value != null ? value.hashCode() : 0;
}
/**
* @see java.lang.Object#equals(Object)
*/
@Override
public boolean equals(final Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
final ConstantExpression that = (ConstantExpression) o;
if (value != null && !value.equals(that.value)) {
return false;
}
return true;
}
/**
* Encodes the value of string so that it looks like it would look like when
* it was provided in a selector.
*
* @param s
* @return
*/
public static String encodeString(String s) {
StringBuffer b = new StringBuffer();
b.append('\'');
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == '\'') {
b.append(c);
}
b.append(c);
}
b.append('\'');
return b.toString();
}
}