Add MutableObject

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@137874 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/lang/mutable/MutableObject.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright 2004 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.mutable;
+
+import java.io.Serializable;
+
+/**
+ * A mutable <code>Object</code>.
+ * 
+ * @since 2.1
+ * @version $Id: MutableObject.java,v 1.1 2004/07/08 00:02:35 scolebourne Exp $
+ */
+public class MutableObject
+        implements Mutable, Serializable {
+
+    /** Serialization lock. */
+    private static final long serialVersionUID = 86241875189L;
+
+    /** The mutable value. */
+    private Object value;
+
+    /**
+     * Constructs a new MutableObject with the default value of null.
+     */
+    public MutableObject() {
+        super();
+    }
+
+    /**
+     * Constructs a new MutableObject with the specified value.
+     * 
+     * @param value a value.
+     */
+    public MutableObject(Object value) {
+        super();
+        this.value = value;
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Gets the value.
+     * 
+     * @return the value
+     */
+    public Object getValue() {
+        return this.value;
+    }
+
+    /**
+     * Sets the value.
+     * 
+     * @param value  the value to set
+     */
+    public void setValue(Object value) {
+        this.value = value;;
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Checks if this object equals the specified object.
+     * <p>
+     * The object must be a MutableObject with an equal value to be equal.
+     *
+     * @param obj  the object to compare to
+     * @return true if equal
+     */
+    public boolean equals(Object obj) {
+        if (obj instanceof MutableObject) {
+            Object other = ((MutableObject) obj).value;
+            return (value == other || (value != null && value.equals(other)));
+        }
+        return false;
+    }
+
+    /**
+     * Returns a suitable hashcode for this mutable.
+     *
+     * @return a suitable hashcode
+     */
+    public int hashCode() {
+        return (value == null ? 0 : value.hashCode());
+    }
+
+    /**
+     * Returns the String value of this mutable.
+     *
+     * @return the mutable value as a string
+     */
+    public String toString() {
+        return (value == null ? "null" : value.toString());
+    }
+
+}

src/test/org/apache/commons/lang/mutable/MutableObjectTest.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright 2002-2004 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.mutable;
+
+import junit.framework.Test;
+import junit.framework.TestCase;
+import junit.framework.TestSuite;
+import junit.textui.TestRunner;
+
+/**
+ * JUnit tests.
+ * 
+ * @version $Id: MutableObjectTest.java,v 1.1 2004/07/08 00:02:35 scolebourne Exp $
+ * @see MutableShort
+ */
+public class MutableObjectTest extends TestCase {
+
+    public MutableObjectTest(String testName) {
+        super(testName);
+    }
+
+    public static void main(String[] args) {
+        TestRunner.run(suite());
+    }
+
+    public static Test suite() {
+        return new TestSuite(MutableObjectTest.class);
+    }
+
+    // ----------------------------------------------------------------
+    public void testConstructors() {
+        assertEquals(null, new MutableObject().getValue());
+        
+        Integer i = new Integer(6);
+        assertSame(i, new MutableObject(i).getValue());
+        assertSame("HI", new MutableObject("HI").getValue());
+        assertSame(null, new MutableObject(null).getValue());
+    }
+
+    public void testGetSet() {
+        final MutableObject mutNum = new MutableObject();
+        assertEquals(null, new MutableObject().getValue());
+        
+        mutNum.setValue("HELLO");
+        assertSame("HELLO", mutNum.getValue());
+        
+        mutNum.setValue(null);
+        assertSame(null, mutNum.getValue());
+    }
+
+    public void testEquals() {
+        final MutableObject mutNumA = new MutableObject("ALPHA");
+        final MutableObject mutNumB = new MutableObject("ALPHA");
+        final MutableObject mutNumC = new MutableObject("BETA");
+        final MutableObject mutNumD = new MutableObject(null);
+
+        assertEquals(true, mutNumA.equals(mutNumA));
+        assertEquals(true, mutNumA.equals(mutNumB));
+        assertEquals(true, mutNumB.equals(mutNumA));
+        assertEquals(true, mutNumB.equals(mutNumB));
+        assertEquals(false, mutNumA.equals(mutNumC));
+        assertEquals(false, mutNumB.equals(mutNumC));
+        assertEquals(true, mutNumC.equals(mutNumC));
+        assertEquals(false, mutNumA.equals(mutNumD));
+        assertEquals(true, mutNumD.equals(mutNumD));
+        
+        assertEquals(false, mutNumA.equals(null));
+        assertEquals(false, mutNumA.equals(new Object()));
+        assertEquals(false, mutNumA.equals("0"));
+    }
+
+    public void testHashCode() {
+        final MutableObject mutNumA = new MutableObject("ALPHA");
+        final MutableObject mutNumB = new MutableObject("ALPHA");
+        final MutableObject mutNumC = new MutableObject("BETA");
+        final MutableObject mutNumD = new MutableObject(null);
+
+        assertEquals(true, mutNumA.hashCode() == mutNumA.hashCode());
+        assertEquals(true, mutNumA.hashCode() == mutNumB.hashCode());
+        assertEquals(false, mutNumA.hashCode() == mutNumC.hashCode());
+        assertEquals(false, mutNumA.hashCode() == mutNumD.hashCode());
+        assertEquals(true, mutNumA.hashCode() == "ALPHA".hashCode());
+        assertEquals(0, mutNumD.hashCode());
+    }
+
+    public void testToString() {
+        assertEquals("HI", new MutableObject("HI").toString());
+        assertEquals("10.0", new MutableObject(new Double(10)).toString());
+    }
+
+}

src/test/org/apache/commons/lang/mutable/MutableTestSuite.java

@@ -22,7 +22,7 @@ import junit.textui.TestRunner;
 /**
  * JUnit tests.
  *
- * @version $Id: MutableTestSuite.java,v 1.3 2004/07/07 23:50:28 scolebourne Exp $
+ * @version $Id: MutableTestSuite.java,v 1.4 2004/07/08 00:02:35 scolebourne Exp $
  */
 public class MutableTestSuite {
 
@@ -39,6 +39,7 @@ public class MutableTestSuite {
         suite.addTest(MutableLongTest.suite());
         suite.addTest(MutableFloatTest.suite());
         suite.addTest(MutableDoubleTest.suite());
+        suite.addTest(MutableObjectTest.suite());
 
         return suite;
     }