Moving enum package to back compat 'branch'

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/lang/trunk@749171 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Henri Yandell 2009-03-02 03:39:27 +00:00
parent cf5530f662
commit 5df3e1aad7
4 changed files with 0 additions and 1030 deletions

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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.
*/
package org.apache.commons.lang.enum;
import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.WeakHashMap;
import org.apache.commons.lang.ClassUtils;
import org.apache.commons.lang.StringUtils;
/**
* <p>Abstract superclass for type-safe enums.</p>
*
* <p>One feature of the C programming language lacking in Java is enumerations. The
* C implementation based on ints was poor and open to abuse. The original Java
* recommendation and most of the JDK also uses int constants. It has been recognised
* however that a more robust type-safe class-based solution can be designed. This
* class follows the basic Java type-safe enumeration pattern.</p>
*
* <p><em>NOTE:</em>Due to the way in which Java ClassLoaders work, comparing
* Enum objects should always be done using <code>equals()</code>, not <code>==</code>.
* The equals() method will try == first so in most cases the effect is the same.</p>
*
* <p>Of course, if you actually want (or don't mind) Enums in different class
* loaders being non-equal, then you can use <code>==</code>.</p>
*
* <h4>Simple Enums</h4>
*
* <p>To use this class, it must be subclassed. For example:</p>
*
* <pre>
* public final class ColorEnum extends Enum {
* public static final ColorEnum RED = new ColorEnum("Red");
* public static final ColorEnum GREEN = new ColorEnum("Green");
* public static final ColorEnum BLUE = new ColorEnum("Blue");
*
* private ColorEnum(String color) {
* super(color);
* }
*
* public static ColorEnum getEnum(String color) {
* return (ColorEnum) getEnum(ColorEnum.class, color);
* }
*
* public static Map getEnumMap() {
* return getEnumMap(ColorEnum.class);
* }
*
* public static List getEnumList() {
* return getEnumList(ColorEnum.class);
* }
*
* public static Iterator iterator() {
* return iterator(ColorEnum.class);
* }
* }
* </pre>
*
* <p>As shown, each enum has a name. This can be accessed using <code>getName</code>.</p>
*
* <p>The <code>getEnum</code> and <code>iterator</code> methods are recommended.
* Unfortunately, Java restrictions require these to be coded as shown in each subclass.
* An alternative choice is to use the {@link EnumUtils} class.</p>
*
* <h4>Subclassed Enums</h4>
* <p>A hierarchy of Enum classes can be built. In this case, the superclass is
* unaffected by the addition of subclasses (as per normal Java). The subclasses
* may add additional Enum constants <em>of the type of the superclass</em>. The
* query methods on the subclass will return all of the Enum constants from the
* superclass and subclass.</p>
*
* <pre>
* public final class ExtraColorEnum extends ColorEnum {
* // NOTE: Color enum declared above is final, change that to get this
* // example to compile.
* public static final ColorEnum YELLOW = new ExtraColorEnum("Yellow");
*
* private ExtraColorEnum(String color) {
* super(color);
* }
*
* public static ColorEnum getEnum(String color) {
* return (ColorEnum) getEnum(ExtraColorEnum.class, color);
* }
*
* public static Map getEnumMap() {
* return getEnumMap(ExtraColorEnum.class);
* }
*
* public static List getEnumList() {
* return getEnumList(ExtraColorEnum.class);
* }
*
* public static Iterator iterator() {
* return iterator(ExtraColorEnum.class);
* }
* }
* </pre>
*
* <p>This example will return RED, GREEN, BLUE, YELLOW from the List and iterator
* methods in that order. The RED, GREEN and BLUE instances will be the same (==)
* as those from the superclass ColorEnum. Note that YELLOW is declared as a
* ColorEnum and not an ExtraColorEnum.</p>
*
* <h4>Functional Enums</h4>
*
* <p>The enums can have functionality by defining subclasses and
* overriding the <code>getEnumClass()</code> method:</p>
*
* <pre>
* public static final OperationEnum PLUS = new PlusOperation();
* private static final class PlusOperation extends OperationEnum {
* private PlusOperation() {
* super("Plus");
* }
* public int eval(int a, int b) {
* return a + b;
* }
* }
* public static final OperationEnum MINUS = new MinusOperation();
* private static final class MinusOperation extends OperationEnum {
* private MinusOperation() {
* super("Minus");
* }
* public int eval(int a, int b) {
* return a - b;
* }
* }
*
* private OperationEnum(String color) {
* super(color);
* }
*
* public final Class getEnumClass() { // NOTE: new method!
* return OperationEnum.class;
* }
*
* public abstract double eval(double a, double b);
*
* public static OperationEnum getEnum(String name) {
* return (OperationEnum) getEnum(OperationEnum.class, name);
* }
*
* public static Map getEnumMap() {
* return getEnumMap(OperationEnum.class);
* }
*
* public static List getEnumList() {
* return getEnumList(OperationEnum.class);
* }
*
* public static Iterator iterator() {
* return iterator(OperationEnum.class);
* }
* }
* </pre>
* <p>The code above will work on JDK 1.2. If JDK1.3 and later is used,
* the subclasses may be defined as anonymous.</p>
*
* <h4>Nested class Enums</h4>
*
* <p>Care must be taken with class loading when defining a static nested class
* for enums. The static nested class can be loaded without the surrounding outer
* class being loaded. This can result in an empty list/map/iterator being returned.
* One solution is to define a static block that references the outer class where
* the constants are defined. For example:</p>
*
* <pre>
* public final class Outer {
* public static final BWEnum BLACK = new BWEnum("Black");
* public static final BWEnum WHITE = new BWEnum("White");
*
* // static nested enum class
* public static final class BWEnum extends Enum {
*
* static {
* // explicitly reference BWEnum class to force constants to load
* Object obj = Outer.BLACK;
* }
*
* // ... other methods omitted
* }
* }
* </pre>
*
* <p>Although the above solves the problem, it is not recommended. The best solution
* is to define the constants in the enum class, and hold references in the outer class:
*
* <pre>
* public final class Outer {
* public static final BWEnum BLACK = BWEnum.BLACK;
* public static final BWEnum WHITE = BWEnum.WHITE;
*
* // static nested enum class
* public static final class BWEnum extends Enum {
* // only define constants in enum classes - private if desired
* private static final BWEnum BLACK = new BWEnum("Black");
* private static final BWEnum WHITE = new BWEnum("White");
*
* // ... other methods omitted
* }
* }
* </pre>
*
* <p>For more details, see the 'Nested' test cases.
*
* @deprecated Replaced by {@link org.apache.commons.lang.enums.Enum org.apache.commons.lang.enums.Enum}
* and will be removed in version 3.0. All classes in this package are deprecated and repackaged to
* {@link org.apache.commons.lang.enums} since <code>enum</code> is a Java 1.5 keyword.
* @see org.apache.commons.lang.enums.Enum
* @author Apache Avalon project
* @author Stephen Colebourne
* @author Chris Webb
* @author Mike Bowler
* @since 1.0
* @version $Id$
*/
public abstract class Enum implements Comparable, Serializable {
/**
* Required for serialization support. Lang version 1.0.1 serial compatibility.
*
* @see java.io.Serializable
*/
private static final long serialVersionUID = -487045951170455942L;
// After discussion, the default size for HashMaps is used, as the
// sizing algorithm changes across the JDK versions
/**
* An empty <code>Map</code>, as JDK1.2 didn't have an empty map.
*/
private static final Map EMPTY_MAP = Collections.unmodifiableMap(new HashMap(0));
/**
* <code>Map</code>, key of class name, value of <code>Entry</code>.
*/
private static Map cEnumClasses
// LANG-334: To avoid exposing a mutating map,
// we copy it each time we add to it. This is cheaper than
// using a synchronized map since we are almost entirely reads
= new WeakHashMap();
/**
* The string representation of the Enum.
*/
private final String iName;
/**
* The hashcode representation of the Enum.
*/
private transient final int iHashCode;
/**
* The toString representation of the Enum.
* @since 2.0
*/
protected transient String iToString = null;
/**
* <p>Enable the iterator to retain the source code order.</p>
*/
private static class Entry {
/**
* Map of Enum name to Enum.
*/
final Map map = new HashMap();
/**
* Map of Enum name to Enum.
*/
final Map unmodifiableMap = Collections.unmodifiableMap(map);
/**
* List of Enums in source code order.
*/
final List list = new ArrayList(25);
/**
* Map of Enum name to Enum.
*/
final List unmodifiableList = Collections.unmodifiableList(list);
/**
* <p>Restrictive constructor.</p>
*/
protected Entry() {
super();
}
}
/**
* <p>Constructor to add a new named item to the enumeration.</p>
*
* @param name the name of the enum object,
* must not be empty or <code>null</code>
* @throws IllegalArgumentException if the name is <code>null</code>
* or an empty string
* @throws IllegalArgumentException if the getEnumClass() method returns
* a null or invalid Class
*/
protected Enum(String name) {
super();
init(name);
iName = name;
iHashCode = 7 + getEnumClass().hashCode() + 3 * name.hashCode();
// cannot create toString here as subclasses may want to include other data
}
/**
* Initializes the enumeration.
*
* @param name the enum name
* @throws IllegalArgumentException if the name is null or empty or duplicate
* @throws IllegalArgumentException if the enumClass is null or invalid
*/
private void init(String name) {
if (StringUtils.isEmpty(name)) {
throw new IllegalArgumentException("The Enum name must not be empty or null");
}
Class enumClass = getEnumClass();
if (enumClass == null) {
throw new IllegalArgumentException("getEnumClass() must not be null");
}
Class cls = getClass();
boolean ok = false;
while (cls != null && cls != Enum.class && cls != ValuedEnum.class) {
if (cls == enumClass) {
ok = true;
break;
}
cls = cls.getSuperclass();
}
if (ok == false) {
throw new IllegalArgumentException("getEnumClass() must return a superclass of this class");
}
Entry entry;
synchronized( Enum.class ) { // LANG-334
// create entry
entry = (Entry) cEnumClasses.get(enumClass);
if (entry == null) {
entry = createEntry(enumClass);
Map myMap = new WeakHashMap( ); // we avoid the (Map) constructor to achieve JDK 1.2 support
myMap.putAll( cEnumClasses );
myMap.put(enumClass, entry);
cEnumClasses = myMap;
}
}
if (entry.map.containsKey(name)) {
throw new IllegalArgumentException("The Enum name must be unique, '" + name + "' has already been added");
}
entry.map.put(name, this);
entry.list.add(this);
}
/**
* <p>Handle the deserialization of the class to ensure that multiple
* copies are not wastefully created, or illegal enum types created.</p>
*
* @return the resolved object
*/
protected Object readResolve() {
Entry entry = (Entry) cEnumClasses.get(getEnumClass());
if (entry == null) {
return null;
}
return entry.map.get(getName());
}
//--------------------------------------------------------------------------------
/**
* <p>Gets an <code>Enum</code> object by class and name.</p>
*
* @param enumClass the class of the Enum to get, must not
* be <code>null</code>
* @param name the name of the <code>Enum</code> to get,
* may be <code>null</code>
* @return the enum object, or <code>null</code> if the enum does not exist
* @throws IllegalArgumentException if the enum class
* is <code>null</code>
*/
protected static Enum getEnum(Class enumClass, String name) {
Entry entry = getEntry(enumClass);
if (entry == null) {
return null;
}
return (Enum) entry.map.get(name);
}
/**
* <p>Gets the <code>Map</code> of <code>Enum</code> objects by
* name using the <code>Enum</code> class.</p>
*
* <p>If the requested class has no enum objects an empty
* <code>Map</code> is returned.</p>
*
* @param enumClass the class of the <code>Enum</code> to get,
* must not be <code>null</code>
* @return the enum object Map
* @throws IllegalArgumentException if the enum class is <code>null</code>
* @throws IllegalArgumentException if the enum class is not a subclass of Enum
*/
protected static Map getEnumMap(Class enumClass) {
Entry entry = getEntry(enumClass);
if (entry == null) {
return EMPTY_MAP;
}
return entry.unmodifiableMap;
}
/**
* <p>Gets the <code>List</code> of <code>Enum</code> objects using the
* <code>Enum</code> class.</p>
*
* <p>The list is in the order that the objects were created (source code order).
* If the requested class has no enum objects an empty <code>List</code> is
* returned.</p>
*
* @param enumClass the class of the <code>Enum</code> to get,
* must not be <code>null</code>
* @return the enum object Map
* @throws IllegalArgumentException if the enum class is <code>null</code>
* @throws IllegalArgumentException if the enum class is not a subclass of Enum
*/
protected static List getEnumList(Class enumClass) {
Entry entry = getEntry(enumClass);
if (entry == null) {
return Collections.EMPTY_LIST;
}
return entry.unmodifiableList;
}
/**
* <p>Gets an <code>Iterator</code> over the <code>Enum</code> objects in
* an <code>Enum</code> class.</p>
*
* <p>The <code>Iterator</code> is in the order that the objects were
* created (source code order). If the requested class has no enum
* objects an empty <code>Iterator</code> is returned.</p>
*
* @param enumClass the class of the <code>Enum</code> to get,
* must not be <code>null</code>
* @return an iterator of the Enum objects
* @throws IllegalArgumentException if the enum class is <code>null</code>
* @throws IllegalArgumentException if the enum class is not a subclass of Enum
*/
protected static Iterator iterator(Class enumClass) {
return Enum.getEnumList(enumClass).iterator();
}
//-----------------------------------------------------------------------
/**
* <p>Gets an <code>Entry</code> from the map of Enums.</p>
*
* @param enumClass the class of the <code>Enum</code> to get
* @return the enum entry
*/
private static Entry getEntry(Class enumClass) {
if (enumClass == null) {
throw new IllegalArgumentException("The Enum Class must not be null");
}
if (Enum.class.isAssignableFrom(enumClass) == false) {
throw new IllegalArgumentException("The Class must be a subclass of Enum");
}
Entry entry = (Entry) cEnumClasses.get(enumClass);
return entry;
}
/**
* <p>Creates an <code>Entry</code> for storing the Enums.</p>
*
* <p>This accounts for subclassed Enums.</p>
*
* @param enumClass the class of the <code>Enum</code> to get
* @return the enum entry
*/
private static Entry createEntry(Class enumClass) {
Entry entry = new Entry();
Class cls = enumClass.getSuperclass();
while (cls != null && cls != Enum.class && cls != ValuedEnum.class) {
Entry loopEntry = (Entry) cEnumClasses.get(cls);
if (loopEntry != null) {
entry.list.addAll(loopEntry.list);
entry.map.putAll(loopEntry.map);
break; // stop here, as this will already have had superclasses added
}
cls = cls.getSuperclass();
}
return entry;
}
//-----------------------------------------------------------------------
/**
* <p>Retrieve the name of this Enum item, set in the constructor.</p>
*
* @return the <code>String</code> name of this Enum item
*/
public final String getName() {
return iName;
}
/**
* <p>Retrieves the Class of this Enum item, set in the constructor.</p>
*
* <p>This is normally the same as <code>getClass()</code>, but for
* advanced Enums may be different. If overridden, it must return a
* constant value.</p>
*
* @return the <code>Class</code> of the enum
* @since 2.0
*/
public Class getEnumClass() {
return getClass();
}
/**
* <p>Tests for equality.</p>
*
* <p>Two Enum objects are considered equal
* if they have the same class names and the same names.
* Identity is tested for first, so this method usually runs fast.</p>
*
* <p>If the parameter is in a different class loader than this instance,
* reflection is used to compare the names.</p>
*
* @param other the other object to compare for equality
* @return <code>true</code> if the Enums are equal
*/
public final boolean equals(Object other) {
if (other == this) {
return true;
} else if (other == null) {
return false;
} else if (other.getClass() == this.getClass()) {
// Ok to do a class cast to Enum here since the test above
// guarantee both
// classes are in the same class loader.
return iName.equals(((Enum) other).iName);
} else {
// This and other are in different class loaders, we must check indirectly
if (other.getClass().getName().equals(this.getClass().getName()) == false) {
return false;
}
return iName.equals( getNameInOtherClassLoader(other) );
}
}
/**
* <p>Returns a suitable hashCode for the enumeration.</p>
*
* @return a hashcode based on the name
*/
public final int hashCode() {
return iHashCode;
}
/**
* <p>Tests for order.</p>
*
* <p>The default ordering is alphabetic by name, but this
* can be overridden by subclasses.</p>
*
* <p>If the parameter is in a different class loader than this instance,
* reflection is used to compare the names.</p>
*
* @see java.lang.Comparable#compareTo(Object)
* @param other the other object to compare to
* @return -ve if this is less than the other object, +ve if greater
* than, <code>0</code> of equal
* @throws ClassCastException if other is not an Enum
* @throws NullPointerException if other is <code>null</code>
*/
public int compareTo(Object other) {
if (other == this) {
return 0;
}
if (other.getClass() != this.getClass()) {
if (other.getClass().getName().equals(this.getClass().getName())) {
return iName.compareTo( getNameInOtherClassLoader(other) );
}
throw new ClassCastException(
"Different enum class '" + ClassUtils.getShortClassName(other.getClass()) + "'");
}
return iName.compareTo(((Enum) other).iName);
}
/**
* <p>Use reflection to return an objects class name.</p>
*
* @param other The object to determine the class name for
* @return The class name
*/
private String getNameInOtherClassLoader(Object other) {
try {
Method mth = other.getClass().getMethod("getName", null);
String name = (String) mth.invoke(other, null);
return name;
} catch (NoSuchMethodException e) {
// ignore - should never happen
} catch (IllegalAccessException e) {
// ignore - should never happen
} catch (InvocationTargetException e) {
// ignore - should never happen
}
throw new IllegalStateException("This should not happen");
}
/**
* <p>Human readable description of this Enum item.</p>
*
* @return String in the form <code>type[name]</code>, for example:
* <code>Color[Red]</code>. Note that the package name is stripped from
* the type name.
*/
public String toString() {
if (iToString == null) {
String shortName = ClassUtils.getShortClassName(getEnumClass());
iToString = shortName + "[" + getName() + "]";
}
return iToString;
}
}

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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.
*/
package org.apache.commons.lang.enum;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
* <p>Utility class for accessing and manipulating {@link Enum}s.</p>
*
* @deprecated Replaced by {@link org.apache.commons.lang.enums.EnumUtils org.apache.commons.lang.enums.EnumUtils}
* and will be removed in version 3.0. All classes in this package are deprecated and repackaged to
* {@link org.apache.commons.lang.enums} since <code>enum</code> is a Java 1.5 keyword.
* @see org.apache.commons.lang.enums.EnumUtils
* @see Enum
* @see ValuedEnum
* @author Stephen Colebourne
* @author Gary Gregory
* @since 1.0
* @version $Id$
*/
public class EnumUtils {
/**
* Public constructor. This class should not normally be instantiated.
* @since 2.0
*/
public EnumUtils() {
super();
}
/**
* <p>Gets an <code>Enum</code> object by class and name.</p>
*
* @param enumClass the class of the <code>Enum</code> to get
* @param name the name of the Enum to get, may be <code>null</code>
* @return the enum object
* @throws IllegalArgumentException if the enum class is <code>null</code>
*/
public static Enum getEnum(Class enumClass, String name) {
return Enum.getEnum(enumClass, name);
}
/**
* <p>Gets a <code>ValuedEnum</code> object by class and value.</p>
*
* @param enumClass the class of the <code>Enum</code> to get
* @param value the value of the <code>Enum</code> to get
* @return the enum object, or null if the enum does not exist
* @throws IllegalArgumentException if the enum class is <code>null</code>
*/
public static ValuedEnum getEnum(Class enumClass, int value) {
return (ValuedEnum) ValuedEnum.getEnum(enumClass, value);
}
/**
* <p>Gets the <code>Map</code> of <code>Enum</code> objects by
* name using the <code>Enum</code> class.</p>
*
* <p>If the requested class has no enum objects an empty
* <code>Map</code> is returned. The <code>Map</code> is unmodifiable.</p>
*
* @param enumClass the class of the <code>Enum</code> to get
* @return the enum object Map
* @throws IllegalArgumentException if the enum class is <code>null</code>
* @throws IllegalArgumentException if the enum class is not a subclass
* of <code>Enum</code>
*/
public static Map getEnumMap(Class enumClass) {
return Enum.getEnumMap(enumClass);
}
/**
* <p>Gets the <code>List</code> of <code>Enum</code> objects using
* the <code>Enum</code> class.</p>
*
* <p>The list is in the order that the objects were created
* (source code order).</p>
*
* <p>If the requested class has no enum objects an empty
* <code>List</code> is returned. The <code>List</code> is unmodifiable.</p>
*
* @param enumClass the class of the Enum to get
* @return the enum object Map
* @throws IllegalArgumentException if the enum class is <code>null</code>
* @throws IllegalArgumentException if the enum class is not a subclass
* of <code>Enum</code>
*/
public static List getEnumList(Class enumClass) {
return Enum.getEnumList(enumClass);
}
/**
* <p>Gets an <code>Iterator</code> over the <code>Enum</code> objects
* in an <code>Enum</code> class.</p>
*
* <p>The iterator is in the order that the objects were created
* (source code order).</p>
*
* <p>If the requested class has no enum objects an empty
* <code>Iterator</code> is returned. The <code>Iterator</code>
* is unmodifiable.</p>
*
* @param enumClass the class of the <code>Enum</code> to get
* @return an <code>Iterator</code> of the <code>Enum</code> objects
* @throws IllegalArgumentException if the enum class is <code>null</code>
* @throws IllegalArgumentException if the enum class is not a subclass of <code>Enum</code>
*/
public static Iterator iterator(Class enumClass) {
return Enum.getEnumList(enumClass).iterator();
}
}

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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.
*/
package org.apache.commons.lang.enum;
import java.util.Iterator;
import java.util.List;
import org.apache.commons.lang.ClassUtils;
/**
* <p>Abstract superclass for type-safe enums with integer values suitable
* for use in <code>switch</code> statements.</p>
*
* <p><em>NOTE:</em>Due to the way in which Java ClassLoaders work, comparing
* <code>Enum</code> objects should always be done using the equals() method,
* not <code>==</code>. The equals() method will try <code>==</code> first so
* in most cases the effect is the same.</p>
*
* <p>To use this class, it must be subclassed. For example:</p>
*
* <pre>
* public final class JavaVersionEnum extends ValuedEnum {
* //standard enums for version of JVM
* public static final int JAVA1_0_VALUE = 100;
* public static final int JAVA1_1_VALUE = 110;
* public static final int JAVA1_2_VALUE = 120;
* public static final int JAVA1_3_VALUE = 130;
* public static final JavaVersionEnum JAVA1_0 = new JavaVersionEnum( "Java 1.0", JAVA1_0_VALUE );
* public static final JavaVersionEnum JAVA1_1 = new JavaVersionEnum( "Java 1.1", JAVA1_1_VALUE );
* public static final JavaVersionEnum JAVA1_2 = new JavaVersionEnum( "Java 1.2", JAVA1_2_VALUE );
* public static final JavaVersionEnum JAVA1_3 = new JavaVersionEnum( "Java 1.3", JAVA1_3_VALUE );
*
* private JavaVersionEnum(String name, int value) {
* super( name, value );
* }
*
* public static JavaVersionEnum getEnum(String javaVersion) {
* return (JavaVersionEnum) getEnum(JavaVersionEnum.class, javaVersion);
* }
*
* public static JavaVersionEnum getEnum(int javaVersion) {
* return (JavaVersionEnum) getEnum(JavaVersionEnum.class, javaVersion);
* }
*
* public static Map getEnumMap() {
* return getEnumMap(JavaVersionEnum.class);
* }
*
* public static List getEnumList() {
* return getEnumList(JavaVersionEnum.class);
* }
*
* public static Iterator iterator() {
* return iterator(JavaVersionEnum.class);
* }
* }
* </pre>
*
* <p>The above class could then be used as follows:</p>
*
* <pre>
* public void doSomething(JavaVersionEnum ver) {
* switch (ver.getValue()) {
* case JAVA1_0_VALUE:
* // ...
* break;
* case JAVA1_1_VALUE:
* // ...
* break;
* //...
* }
* }
* </pre>
*
* <p>As shown, each enum has a name and a value. These can be accessed using
* <code>getName</code> and <code>getValue</code>.</p>
*
* <p>The <code>getEnum</code> and <code>iterator</code> methods are recommended.
* Unfortunately, Java restrictions require these to be coded as shown in each subclass.
* An alternative choice is to use the {@link EnumUtils} class.</p>
*
* @deprecated Replaced by {@link org.apache.commons.lang.enums.ValuedEnum org.apache.commons.lang.enums.ValuedEnum}
* and will be removed in version 3.0. All classes in this package are deprecated and repackaged to
* {@link org.apache.commons.lang.enums} since <code>enum</code> is a Java 1.5 keyword.
* @see org.apache.commons.lang.enums.ValuedEnum
* @author Apache Avalon project
* @author Stephen Colebourne
* @since 1.0
* @version $Id$
*/
public abstract class ValuedEnum extends Enum {
/**
* Required for serialization support. Lang version 1.0.1 serial compatibility.
*
* @see java.io.Serializable
*/
private static final long serialVersionUID = -7129650521543789085L;
/**
* The value contained in enum.
*/
private final int iValue;
/**
* Constructor for enum item.
*
* @param name the name of enum item
* @param value the value of enum item
*/
protected ValuedEnum(String name, int value) {
super(name);
iValue = value;
}
/**
* <p>Gets an <code>Enum</code> object by class and value.</p>
*
* <p>This method loops through the list of <code>Enum</code>,
* thus if there are many <code>Enum</code>s this will be
* slow.</p>
*
* @param enumClass the class of the <code>Enum</code> to get
* @param value the value of the <code>Enum</code> to get
* @return the enum object, or null if the enum does not exist
* @throws IllegalArgumentException if the enum class is <code>null</code>
*/
protected static Enum getEnum(Class enumClass, int value) {
if (enumClass == null) {
throw new IllegalArgumentException("The Enum Class must not be null");
}
List list = Enum.getEnumList(enumClass);
for (Iterator it = list.iterator(); it.hasNext();) {
ValuedEnum enumeration = (ValuedEnum) it.next();
if (enumeration.getValue() == value) {
return enumeration;
}
}
return null;
}
/**
* <p>Get value of enum item.</p>
*
* @return the enum item's value.
*/
public final int getValue() {
return iValue;
}
/**
* <p>Tests for order.</p>
*
* <p>The default ordering is numeric by value, but this
* can be overridden by subclasses.</p>
*
* @see java.lang.Comparable#compareTo(Object)
* @param other the other object to compare to
* @return -ve if this is less than the other object, +ve if greater than,
* <code>0</code> of equal
* @throws ClassCastException if other is not an <code>Enum</code>
* @throws NullPointerException if other is <code>null</code>
*/
public int compareTo(Object other) {
return iValue - ((ValuedEnum) other).iValue;
}
/**
* <p>Human readable description of this <code>Enum</code> item.</p>
*
* @return String in the form <code>type[name=value]</code>, for example:
* <code>JavaVersion[Java 1.0=100]</code>. Note that the package name is
* stripped from the type name.
*/
public String toString() {
if (iToString == null) {
String shortName = ClassUtils.getShortClassName(getEnumClass());
iToString = shortName + "[" + getName() + "=" + getValue() + "]";
}
return iToString;
}
}

View File

@ -1,62 +0,0 @@
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(the "License"); you may not use this file except in compliance with
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<html>
<body>
<p>
<b>Deprecated</b> and replaced by {@link org.apache.commons.lang.enums}
and will be removed in version 3.0.
</p>
<p>
All classes in this package are deprecated and repackaged to {@link org.apache.commons.lang.enums}
since <code>enum</code> is a Java 1.5 keyword.
</p>
<p>
Provides an implementation of the C style <code>enum</code> in the Java world.
</p>
<p>
The classic example being an RGB color enumeration.
</p>
<pre>
public final class ColorEnum extends Enum {
public static final ColorEnum RED = new ColorEnum("Red");
public static final ColorEnum GREEN = new ColorEnum("Green");
public static final ColorEnum BLUE = new ColorEnum("Blue");
private ColorEnum(String color) {
super(color);
}
public static ColorEnum getEnum(String color) {
return (ColorEnum) getEnum(ColorEnum.class, color);
}
public static Map getEnumMap() {
return getEnumMap(ColorEnum.class);
}
public static List getEnumList() {
return getEnumList(ColorEnum.class);
}
public static Iterator iterator() {
return iterator(ColorEnum.class);
}
}
</pre>
@since 1.0
</body>
</html>