org.protempa.proposition.value.NominalValue Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of protempa-framework Show documentation
Show all versions of protempa-framework Show documentation
Protempa Framework is the core of Protempa.
/*
* #%L
* Protempa Framework
* %%
* Copyright (C) 2012 - 2013 Emory University
* %%
* Licensed 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.
* #L%
*/
package org.protempa.proposition.value;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.text.Format;
import java.util.Map;
import org.apache.commons.collections4.map.ReferenceMap;
import org.apache.commons.lang3.builder.ToStringBuilder;
/**
* Represents a {@link String} value.
*
* @author Andrew Post
*/
public final class NominalValue implements Value, Comparable,
Serializable {
private static final long serialVersionUID = 440118249272295573L;
private String val;
private transient volatile int hashCode;
private static final Map cache = new ReferenceMap<>();
/**
* Creates a new nominal value. If val's length is less than 20
* characters, the created {@link NominalValue} object will be cached and
* reused.
*
* @param val a {@link String}. If null, {@link NominalValue}
* with "" will be created.
* @return a {@link NominalValue}.
*/
public static NominalValue getInstance(String val) {
if (val != null && val.length() < 20) {
NominalValue result;
synchronized (cache) {
result = cache.get(val);
if (result == null) {
result = new NominalValue(val);
cache.put(val, result);
}
}
return result;
} else {
return new NominalValue(val);
}
}
/**
* Creates a new nominal value with the given value. The recommended way to
* create nominal values is with {@link #getInstance(java.lang.String) }.
*
* @param val a String. If null, the default
* string is used ("").
*/
public NominalValue(String val) {
if (val != null) {
this.val = val;
} else {
this.val = "";
}
}
@Override
public NominalValue replace() {
NominalValue result;
synchronized (cache) {
result = cache.get(this.val);
}
if (result != null) {
return result;
} else {
return this;
}
}
@Override
public int hashCode() {
if (this.hashCode == 0) {
this.hashCode = val.hashCode();
}
return this.hashCode;
}
/**
* Compares this nominal value and another for string equality.
*
* @param obj another object.
* @return true if the two nominal values' strings are equal,
* false if not.
*/
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final NominalValue other = (NominalValue) obj;
return this.val.equals(other.val);
}
/**
* Gets the value as a Java {@link String}.
*
* @return a {@link String}.
*/
public String getString() {
return val;
}
/**
* Returns the same thing as {@link #getString}.
*/
@Override
public String getFormatted() {
return val;
}
@Override
public String format(Format format) {
if (format == null) {
return getFormatted();
} else {
return format.format(this.val);
}
}
@Override
public ValueType getType() {
return ValueType.NOMINALVALUE;
}
/**
* Compares this nominal value and another lexically. If the argument is a
* {@link ListValue}, it checks this string for membership in the list.
*
* @param o another {@link Value}.
* @return If the provided value is a {@link NominalValue}, returns null {@link ValueComparator#GREATER_THAN},
* {@link ValueComparator#LESS_THAN} or {@link ValueComparator#EQUAL_TO}
* depending on whether this nominal value is lexically greater than, less
* than or equal to the nominal value provided as argument. If the provided
* value is a {@link ValueList}, returns {@link ValueComparator#IN} if this
* object is a member of the list, or {@link ValueComparator#NOT_IN} if not.
* Otherwise, returns {@link ValueComparator#UNKNOWN}.
*/
@Override
public ValueComparator compare(Value o) {
if (o == null) {
return ValueComparator.NOT_EQUAL_TO;
}
switch (o.getType()) {
case NOMINALVALUE:
NominalValue other = (NominalValue) o;
int comp = compareTo(other);
return comp > 0 ? ValueComparator.GREATER_THAN
: (comp < 0 ? ValueComparator.LESS_THAN
: ValueComparator.EQUAL_TO);
case VALUELIST:
ValueList vl = (ValueList) o;
return vl.contains(this) ? ValueComparator.IN : ValueComparator.NOT_IN;
default:
return ValueComparator.NOT_EQUAL_TO;
}
}
@Override
public void accept(ValueVisitor valueVisitor) {
if (valueVisitor == null) {
throw new IllegalArgumentException("valueVisitor cannot be null");
}
valueVisitor.visit(this);
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
private void writeObject(ObjectOutputStream s) throws IOException {
s.writeObject(this.val);
}
private void readObject(ObjectInputStream s) throws IOException,
ClassNotFoundException {
String tmpVal = (String) s.readObject();
this.val = tmpVal != null ? tmpVal : "";
if (tmpVal != null && tmpVal.length() < 20) {
if (!cache.containsKey(tmpVal)) {
cache.put(tmpVal, this);
}
}
}
@Override
public int compareTo(NominalValue t) {
return this.val.compareTo(t.val);
}
@Override
public NominalValueBuilder asBuilder() {
return new NominalValueBuilder(this);
}
}