Mega Code Archive
A mutable boolean wrapper
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/*
* 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.
*/
import java.io.Serializable;
/**
* A mutable <code>boolean</code> wrapper.
*
* @see Boolean
* @since 2.2
* @author Apache Software Foundation
* @version $Id: MutableBoolean.java 491052 2006-12-29 17:16:37Z scolebourne $
*/
public class MutableBoolean implements Mutable, Serializable, Comparable {
/**
* Required for serialization support.
*
* @see java.io.Serializable
*/
private static final long serialVersionUID = -4830728138360036487L;
/** The mutable value. */
private boolean value;
/**
* Constructs a new MutableBoolean with the default value of false.
*/
public MutableBoolean() {
super();
}
/**
* Constructs a new MutableBoolean with the specified value.
*
* @param value
* a value.
*/
public MutableBoolean(boolean value) {
super();
this.value = value;
}
/**
* Constructs a new MutableBoolean with the specified value.
*
* @param value
* a value.
* @throws NullPointerException
* if the object is null
*/
public MutableBoolean(Boolean value) {
super();
this.value = value.booleanValue();
}
// -----------------------------------------------------------------------
/**
* Returns the value of this MutableBoolean as a boolean.
*
* @return the boolean value represented by this object.
*/
public boolean booleanValue() {
return value;
}
/**
* Compares this mutable to another in ascending order.
*
* @param obj
* the mutable to compare to
* @return zero if this object represents the same boolean value as the argument; a positive value if this object
* represents true and the argument represents false; and a negative value if this object represents false
* and the argument represents true
* @throws ClassCastException
* if the argument is not a MutableInt
*/
public int compareTo(Object obj) {
MutableBoolean other = (MutableBoolean) obj;
boolean anotherVal = other.value;
return value == anotherVal ? 0 : (value ? 1 : -1);
}
// -----------------------------------------------------------------------
/**
* Compares this object to the specified object. The result is <code>true</code> if and only if the argument is
* not <code>null</code> and is an <code>MutableBoolean</code> object that contains the same
* <code>boolean</code> value as this object.
*
* @param obj
* the object to compare with.
* @return <code>true</code> if the objects are the same; <code>false</code> otherwise.
*/
public boolean equals(Object obj) {
if (obj instanceof MutableBoolean) {
return value == ((MutableBoolean) obj).booleanValue();
}
return false;
}
// -----------------------------------------------------------------------
/**
* Gets the value as a Boolean instance.
*
* @return the value as a Boolean
*/
public Object getValue() {
return this.value;
}
/**
* Returns a suitable hashcode for this mutable.
*
* @return the integer <code>1231</code> if this object represents <code>true</code>; returns the integer
* <code>1237</code> if this object represents <code>false</code>.
*/
public int hashCode() {
return value ? Boolean.TRUE.hashCode() : Boolean.FALSE.hashCode();
}
/**
* Sets the value.
*
* @param value
* the value to set
*/
public void setValue(boolean value) {
this.value = value;
}
/**
* Sets the value from any Boolean instance.
*
* @param value
* the value to set
* @throws NullPointerException
* if the object is null
* @throws ClassCastException
* if the type is not a {@link Boolean}
*/
public void setValue(Object value) {
setValue(((Boolean) value).booleanValue());
}
/**
* Returns the String value of this mutable.
*
* @return the mutable value as a string
*/
public String toString() {
return String.valueOf(value);
}
}
/*
* 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.
*/
/**
* Provides mutable access to a value.
* <p>
* <code>Mutable</code> is used as a generic interface to the implementations in this package.
* <p>
* A typical use case would be to enable a primitive or string to be passed to a method and allow that method to
* effectively change the value of the primitive/string. Another use case is to store a frequently changing primitive in
* a collection (for example a total in a map) without needing to create new Integer/Long wrapper objects.
*
* @author Matthew Hawthorne
* @since 2.1
* @version $Id: Mutable.java 618693 2008-02-05 16:33:29Z sebb $
*/
interface Mutable {
/**
* Gets the value of this mutable.
*
* @return the stored value
*/
Object getValue();
/**
* Sets the value of this mutable.
*
* @param value
* the value to store
* @throws NullPointerException
* if the object is null and null is invalid
* @throws ClassCastException
* if the type is invalid
*/
void setValue(Object value);
}
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