com.groupbyinc.common.joda.time.field.UnsupportedDurationField Maven / Gradle / Ivy
/*
* Copyright 2001-2009 Stephen Colebourne
*
* 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.
*/
package org.joda.time.field;
import java.io.Serializable;
import java.util.HashMap;
import org.joda.time.DurationField;
import org.joda.time.DurationFieldType;
/**
* A placeholder implementation to use when a duration field is not supported.
*
* UnsupportedDurationField is thread-safe and immutable.
*
* @author Brian S O'Neill
* @since 1.0
*/
public final class UnsupportedDurationField extends DurationField implements Serializable {
/** Serialization lock. */
private static final long serialVersionUID = -6390301302770925357L;
/** The cache of unsupported duration field instances */
private static HashMap cCache;
/**
* Gets an instance of UnsupportedDurationField for a specific named field.
* The returned instance is cached.
*
* @param type the type to obtain
* @return the instance
*/
public static synchronized UnsupportedDurationField getInstance(DurationFieldType type) {
UnsupportedDurationField field;
if (cCache == null) {
cCache = new HashMap(7);
field = null;
} else {
field = cCache.get(type);
}
if (field == null) {
field = new UnsupportedDurationField(type);
cCache.put(type, field);
}
return field;
}
/** The name of the field */
private final DurationFieldType iType;
/**
* Constructor.
*
* @param type the type to use
*/
private UnsupportedDurationField(DurationFieldType type) {
iType = type;
}
//-----------------------------------------------------------------------
// Design note: Simple Accessors return a suitable value, but methods
// intended to perform calculations throw an UnsupportedOperationException.
public final DurationFieldType getType() {
return iType;
}
public String getName() {
return iType.getName();
}
/**
* This field is not supported.
*
* @return false always
*/
public boolean isSupported() {
return false;
}
/**
* This field is precise.
*
* @return true always
*/
public boolean isPrecise() {
return true;
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public int getValue(long duration) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public long getValueAsLong(long duration) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public int getValue(long duration, long instant) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public long getValueAsLong(long duration, long instant) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public long getMillis(int value) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public long getMillis(long value) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public long getMillis(int value, long instant) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public long getMillis(long value, long instant) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public long add(long instant, int value) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public long add(long instant, long value) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public int getDifference(long minuendInstant, long subtrahendInstant) {
throw unsupported();
}
/**
* Always throws UnsupportedOperationException
*
* @throws UnsupportedOperationException
*/
public long getDifferenceAsLong(long minuendInstant, long subtrahendInstant) {
throw unsupported();
}
/**
* Always returns zero.
*
* @return zero always
*/
public long getUnitMillis() {
return 0;
}
/**
* Always returns zero, indicating that sort order is not relevent.
*
* @return zero always
*/
public int compareTo(DurationField durationField) {
return 0;
}
//------------------------------------------------------------------------
/**
* Compares this duration field to another.
*
* @param obj the object to compare to
* @return true if equal
*/
public boolean equals(Object obj) {
if (this == obj) {
return true;
} else if (obj instanceof UnsupportedDurationField) {
UnsupportedDurationField other = (UnsupportedDurationField) obj;
if (other.getName() == null) {
return (getName() == null);
}
return (other.getName().equals(getName()));
}
return false;
}
/**
* Gets a suitable hashcode.
*
* @return the hashcode
*/
public int hashCode() {
return getName().hashCode();
}
/**
* Get a suitable debug string.
*
* @return debug string
*/
public String toString() {
return "UnsupportedDurationField[" + getName() + ']';
}
/**
* Ensure proper singleton serialization
*/
private Object readResolve() {
return getInstance(iType);
}
private UnsupportedOperationException unsupported() {
return new UnsupportedOperationException(iType + " field is unsupported");
}
}