LANG-259 - Fix compareTo to check the type is the same

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@432748 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/lang/enums/ValuedEnum.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2005 The Apache Software Foundation.
+ * Copyright 2002-2006 The Apache Software Foundation.
  * 
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,8 @@
  */
 package org.apache.commons.lang.enums;
 
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.Iterator;
 import java.util.List;
 
@@ -166,6 +168,10 @@ public final int getValue() {
      * <p>The default ordering is numeric by value, but this
      * can be overridden by subclasses.</p>
      *
+     * <p>NOTE: From v2.2 the enums must be of the same type.
+     * If the parameter is in a different class loader than this instance,
+     * reflection is used to compare the values.</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,
@@ -174,9 +180,40 @@ public final int getValue() {
      * @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 iValue - getValueInOtherClassLoader(other);
+            }
+            throw new ClassCastException(
+                    "Different enum class '" + ClassUtils.getShortClassName(other.getClass()) + "'");
+        }
         return iValue - ((ValuedEnum) other).iValue;
     }
 
+    /**
+     * <p>Use reflection to return an objects value.</p>
+     *
+     * @param other  the object to determine the value for
+     * @return the value
+     */
+    private int getValueInOtherClassLoader(Object other) {
+        try {
+            Method mth = other.getClass().getMethod("getValue", null);
+            Integer value = (Integer) mth.invoke(other, null);
+            return value.intValue();
+        } 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 <code>Enum</code> item.</p>
      *

src/test/org/apache/commons/lang/enums/EnumEqualsTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2005 The Apache Software Foundation.
+ * Copyright 2004-2006 The Apache Software Foundation.
  * 
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,8 @@
  */
 package org.apache.commons.lang.enums;
 
+import java.net.URLClassLoader;
+
 import junit.framework.Test;
 import junit.framework.TestCase;
 import junit.framework.TestSuite;
@@ -88,6 +90,34 @@ public void testEquals() {
         assertEquals(false, CarColorEnum.RED.equals(new TotallyUnrelatedClass("some")));
     }
 
+    public void testEquals_classloader_equal() throws Exception {
+        ClassLoader cl = ColorEnum.class.getClassLoader();
+        if (cl instanceof URLClassLoader) {
+            URLClassLoader urlCL = (URLClassLoader) cl;
+            URLClassLoader urlCL1 = new URLClassLoader(urlCL.getURLs(), null);
+            URLClassLoader urlCL2 = new URLClassLoader(urlCL.getURLs(), null);
+            Class otherEnumClass1 = urlCL1.loadClass("org.apache.commons.lang.enums.ColorEnum");
+            Class otherEnumClass2 = urlCL2.loadClass("org.apache.commons.lang.enums.ColorEnum");
+            Object blue1 = otherEnumClass1.getDeclaredField("BLUE").get(null);
+            Object blue2 = otherEnumClass2.getDeclaredField("BLUE").get(null);
+            assertEquals(true, blue1.equals(blue2));
+        }
+    }
+
+    public void testEquals_classloader_different() throws Exception {
+        ClassLoader cl = ColorEnum.class.getClassLoader();
+        if (cl instanceof URLClassLoader) {
+            URLClassLoader urlCL = (URLClassLoader) cl;
+            URLClassLoader urlCL1 = new URLClassLoader(urlCL.getURLs(), null);
+            URLClassLoader urlCL2 = new URLClassLoader(urlCL.getURLs(), null);
+            Class otherEnumClass1 = urlCL1.loadClass("org.apache.commons.lang.enums.ColorEnum");
+            Class otherEnumClass2 = urlCL2.loadClass("org.apache.commons.lang.enums.ColorEnum");
+            Object blue1 = otherEnumClass1.getDeclaredField("BLUE").get(null);
+            Object blue2 = otherEnumClass2.getDeclaredField("RED").get(null);
+            assertEquals(false, blue1.equals(blue2));
+        }
+    }
+
     //-----------------------------------------------------------------------
     public void testCompareTo() {
         try {

src/test/org/apache/commons/lang/enums/ValuedEnumTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2005 The Apache Software Foundation.
+ * Copyright 2002-2006 The Apache Software Foundation.
  * 
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
  */
 package org.apache.commons.lang.enums;
 
+import java.net.URLClassLoader;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -64,11 +65,103 @@ public void testCompareTo() {
         assertTrue(ValuedColorEnum.BLUE.compareTo(ValuedColorEnum.RED) > 0);
     }
 
+    public void testCompareTo_classloader_equal() throws Exception {
+        ClassLoader cl = ValuedColorEnum.class.getClassLoader();
+        if (cl instanceof URLClassLoader) {
+            URLClassLoader urlCL = (URLClassLoader) cl;
+            URLClassLoader urlCL1 = new URLClassLoader(urlCL.getURLs(), null);
+            URLClassLoader urlCL2 = new URLClassLoader(urlCL.getURLs(), null);
+            Class otherEnumClass1 = urlCL1.loadClass("org.apache.commons.lang.enums.ValuedColorEnum");
+            Class otherEnumClass2 = urlCL2.loadClass("org.apache.commons.lang.enums.ValuedColorEnum");
+            Object blue1 = otherEnumClass1.getDeclaredField("BLUE").get(null);
+            Object blue2 = otherEnumClass2.getDeclaredField("BLUE").get(null);
+            assertTrue(((Comparable) blue1).compareTo(blue2) == 0);
+        }
+    }
+
+    public void testCompareTo_classloader_different() throws Exception {
+        ClassLoader cl = ValuedColorEnum.class.getClassLoader();
+        if (cl instanceof URLClassLoader) {
+            URLClassLoader urlCL = (URLClassLoader) cl;
+            URLClassLoader urlCL1 = new URLClassLoader(urlCL.getURLs(), null);
+            URLClassLoader urlCL2 = new URLClassLoader(urlCL.getURLs(), null);
+            Class otherEnumClass1 = urlCL1.loadClass("org.apache.commons.lang.enums.ValuedColorEnum");
+            Class otherEnumClass2 = urlCL2.loadClass("org.apache.commons.lang.enums.ValuedColorEnum");
+            Object blue1 = otherEnumClass1.getDeclaredField("BLUE").get(null);
+            Object blue2 = otherEnumClass2.getDeclaredField("RED").get(null);
+            assertTrue(((Comparable) blue1).compareTo(blue2) != 0);
+        }
+    }
+
+    public void testCompareTo_nonEnumType() {
+        try {
+            ValuedColorEnum.BLUE.compareTo(new TotallyUnrelatedClass(ValuedColorEnum.BLUE.getValue()));
+            fail();
+        } catch (ClassCastException ex) {
+            // expected
+        }
+    }
+
+    public void testCompareTo_otherEnumType() {
+        try {
+            ValuedColorEnum.BLUE.compareTo(ValuedLanguageEnum.ENGLISH);
+            fail();
+        } catch (ClassCastException ex) {
+            // expected
+        }
+    }
+
+    public void testCompareTo_otherType() {
+        try {
+            ValuedColorEnum.BLUE.compareTo("Blue");
+            fail();
+        } catch (ClassCastException ex) {
+            // expected
+        }
+    }
+
+    public void testCompareTo_null() {
+        try {
+            ValuedColorEnum.BLUE.compareTo(null);
+            fail();
+        } catch (NullPointerException ex) {
+            // expected
+        }
+    }
+
     public void testEquals() {
         assertSame(ValuedColorEnum.RED, ValuedColorEnum.RED);
         assertSame(ValuedColorEnum.getEnum("Red"), ValuedColorEnum.RED);
     }
 
+    public void testEquals_classloader_equal() throws Exception {
+        ClassLoader cl = ValuedColorEnum.class.getClassLoader();
+        if (cl instanceof URLClassLoader) {
+            URLClassLoader urlCL = (URLClassLoader) cl;
+            URLClassLoader urlCL1 = new URLClassLoader(urlCL.getURLs(), null);
+            URLClassLoader urlCL2 = new URLClassLoader(urlCL.getURLs(), null);
+            Class otherEnumClass1 = urlCL1.loadClass("org.apache.commons.lang.enums.ValuedColorEnum");
+            Class otherEnumClass2 = urlCL2.loadClass("org.apache.commons.lang.enums.ValuedColorEnum");
+            Object blue1 = otherEnumClass1.getDeclaredField("BLUE").get(null);
+            Object blue2 = otherEnumClass2.getDeclaredField("BLUE").get(null);
+            assertEquals(true, blue1.equals(blue2));
+        }
+    }
+
+    public void testEquals_classloader_different() throws Exception {
+        ClassLoader cl = ValuedColorEnum.class.getClassLoader();
+        if (cl instanceof URLClassLoader) {
+            URLClassLoader urlCL = (URLClassLoader) cl;
+            URLClassLoader urlCL1 = new URLClassLoader(urlCL.getURLs(), null);
+            URLClassLoader urlCL2 = new URLClassLoader(urlCL.getURLs(), null);
+            Class otherEnumClass1 = urlCL1.loadClass("org.apache.commons.lang.enums.ValuedColorEnum");
+            Class otherEnumClass2 = urlCL2.loadClass("org.apache.commons.lang.enums.ValuedColorEnum");
+            Object blue1 = otherEnumClass1.getDeclaredField("BLUE").get(null);
+            Object blue2 = otherEnumClass2.getDeclaredField("RED").get(null);
+            assertEquals(false, blue1.equals(blue2));
+        }
+    }
+
     public void testToString() {
         String toString = ValuedColorEnum.RED.toString();
         assertEquals("ValuedColorEnum[Red=1]", toString);
@@ -132,4 +225,17 @@ public void testSerialization() {
         assertSame(ValuedColorEnum.BLUE, SerializationUtils.clone(ValuedColorEnum.BLUE));
     }
 
+    //-----------------------------------------------------------------------s
+    static class TotallyUnrelatedClass {
+        private final int value;
+
+        public TotallyUnrelatedClass(final int value) {
+            this.value = value;
+        }
+
+        public int getValue() {
+            return value;
+        }
+    }
+
 }

src/test/org/apache/commons/lang/enums/ValuedLanguageEnum.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2006 The Apache Software Foundation.
+ * 
+ * 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.apache.commons.lang.enums;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Language enumeration.
+ *
+ * @author <a href="mailto:scolebourne@joda.org">Stephen Colebourne</a>
+ * @version $Id: ValuedColorEnum.java 161244 2005-04-14 06:16:36Z ggregory $
+ */
+public final class ValuedLanguageEnum extends ValuedEnum {
+    public static final ValuedLanguageEnum ENGLISH = new ValuedLanguageEnum("English", 1);
+    public static final ValuedLanguageEnum FRENCH = new ValuedLanguageEnum("French", 2);
+    public static final ValuedLanguageEnum GERMAN = new ValuedLanguageEnum("German", 3);
+
+    private ValuedLanguageEnum(String color, int value) {
+        super(color, value);
+    }
+
+    public static ValuedLanguageEnum getEnum(String color) {
+        return (ValuedLanguageEnum) getEnum(ValuedLanguageEnum.class, color);
+    }
+
+    public static ValuedLanguageEnum getEnum(int value) {
+        return (ValuedLanguageEnum) getEnum(ValuedLanguageEnum.class, value);
+    }
+
+    public static Map getEnumMap() {
+        return getEnumMap(ValuedLanguageEnum.class);
+    }
+
+    public static List getEnumList() {
+        return getEnumList(ValuedLanguageEnum.class);
+    }
+
+    public static Iterator iterator() {
+        return iterator(ValuedLanguageEnum.class);
+    }
+}