diff --git a/src/java/org/apache/commons/math/fraction/FractionField.java b/src/java/org/apache/commons/math/fraction/FractionField.java index f1672eff6..1c211e746 100644 --- a/src/java/org/apache/commons/math/fraction/FractionField.java +++ b/src/java/org/apache/commons/math/fraction/FractionField.java @@ -31,8 +31,6 @@ import org.apache.commons.math.Field; * @since 2.0 */ public class FractionField implements Field, Serializable { - // TODO: Add Serializable documentation - // TODO: Check Serializable implementation /** Serializable version identifier */ private static final long serialVersionUID = -1257768487499119313L; @@ -67,4 +65,12 @@ public class FractionField implements Field, Serializable { private static final FractionField INSTANCE = new FractionField(); } + /** Handle deserialization of the singleton. + * @return the singleton instance + */ + private Object readResolve() { + // return the singleton instance + return LazyHolder.INSTANCE; + } + } diff --git a/src/test/org/apache/commons/math/fraction/FractionFieldTest.java b/src/test/org/apache/commons/math/fraction/FractionFieldTest.java new file mode 100644 index 000000000..37ece328b --- /dev/null +++ b/src/test/org/apache/commons/math/fraction/FractionFieldTest.java @@ -0,0 +1,44 @@ +/* + * 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.math.fraction; + +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertTrue; + +import org.apache.commons.math.TestUtils; +import org.junit.Test; + +public class FractionFieldTest { + + @Test + public void testZero() { + assertEquals(Fraction.ZERO, FractionField.getInstance().getZero()); + } + + @Test + public void testOne() { + assertEquals(Fraction.ONE, FractionField.getInstance().getOne()); + } + + @Test + public void testSerial() { + // deserializing the singleton should give the singleton itself back + FractionField field = FractionField.getInstance(); + assertTrue(field == TestUtils.serializeAndRecover(field)); + } + +}