Merge branch 'master' of https://github.com/unitsofmeasurement/indriy…

…a.git

src/main/java/tech/units/indriya/unit/ProductUnit.java

@@ -29,6 +29,8 @@
  */
 package tech.units.indriya.unit;
 
+import java.io.InvalidObjectException;
+import java.io.ObjectInputStream;
 import java.io.Serializable;
 import java.util.Arrays;
 import java.util.LinkedHashMap;
@@ -60,7 +62,7 @@
  * @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a>
  * @author <a href="mailto:werner@units.tech">Werner Keil</a>
  * @author Andi Huber
- * @version 1.11, September 27, 2020
+ * @version 1.12, October 1, 2020
  * @since 1.0
  */
 public final class ProductUnit<Q extends Quantity<Q>> extends AbstractUnit<Q> {
@@ -560,4 +562,36 @@ private static boolean arrayEqualsArbitraryOrder(final Element[] e0, final Eleme
             return true;
         }
     }
+
+
+    // -- SERIALIZATION PROXY
+
+    // Chapter 12. Serialization
+    // Bloch, Joshua. Effective Java (p. 339). Pearson Education. 
+
+    private Object writeReplace() {
+        return new SerializationProxy(this);
+    }
+
+    private void readObject(ObjectInputStream stream) throws InvalidObjectException {
+        throw new InvalidObjectException("Proxy required");
+    }
+
+    private static class SerializationProxy implements Serializable {
+        private static final long serialVersionUID = 1L;
+        private final Element[] elements;
+        private final String symbol;
+
+        private SerializationProxy(ProductUnit<?> productUnit) {
+            this.elements = productUnit.elements;
+            this.symbol = productUnit.getSymbol();
+        }
+
+        private Object readResolve() {
+            ProductUnit<?> pu = new ProductUnit<>(elements);
+            pu.setSymbol(symbol);
+            return pu;
+        }
+    }
+
 }

src/test/java/tech/units/indriya/SerializationRoundTrip.java

@@ -0,0 +1,78 @@
+/*
+ * Units of Measurement Reference Implementation
+ * Copyright (c) 2005-2020, Jean-Marie Dautelle, Werner Keil, Otavio Santana.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions
+ *    and the following disclaimer in the documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of JSR-385, Indriya nor the names of their contributors may be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package tech.units.indriya;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
+import org.junit.jupiter.api.Assertions;
+
+/**
+ *
+ * @author Andi Huber
+ */
+public final class SerializationRoundTrip {
+
+    /**
+     * Verify that after a serializing de-serializing cycle given {@code value} is equal to 
+     * the original value.
+     * @param value
+     */
+    public static void assertProperSerializationRoundTrip(Object value) {
+        try {
+            Assertions.assertEquals(value, serializationRoundTrip(value));
+        } catch (Exception e) {
+            Assertions.fail(e);
+        }
+    }
+
+    /**
+     * Returns given {@code value} after doing a serializing de-serializing cycle on it.
+     * @param value
+     */
+    @SuppressWarnings("unchecked")
+    public static <T> T serializationRoundTrip(final T value) throws Exception {
+        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
+            try (ObjectOutputStream oos = new ObjectOutputStream(out)) {
+                oos.writeObject(value);
+                oos.flush();
+            }
+            try (ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray())) {
+                try (ObjectInputStream ois = new ObjectInputStream(in)) {
+                    return (T) ois.readObject();
+                }
+            }
+        }
+    }
+
+
+}

src/test/java/tech/units/indriya/unit/ProductUnitSerializationTest.java

@@ -0,0 +1,62 @@
+/*
+ * Units of Measurement Reference Implementation
+ * Copyright (c) 2005-2020, Jean-Marie Dautelle, Werner Keil, Otavio Santana.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions
+ *    and the following disclaimer in the documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of JSR-385, Indriya nor the names of their contributors may be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package tech.units.indriya.unit;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import tech.units.indriya.SerializationRoundTrip;
+
+/**
+ *
+ * @author Andi Huber
+ */
+class ProductUnitSerializationTest {
+
+    private static final ProductUnit<?> KILOGRAM_METRE = 
+            (ProductUnit<?>) ProductUnit.ofProduct(Units.KILOGRAM, Units.METRE);
+
+    @Test
+    public void productUnitsShouldProperlySerialize() throws Exception {
+        SerializationRoundTrip.assertProperSerializationRoundTrip(KILOGRAM_METRE);
+
+        final ProductUnit<?> unitAfterRoundTrip = SerializationRoundTrip.serializationRoundTrip(KILOGRAM_METRE);
+
+        assertEquals(KILOGRAM_METRE.hashCode(), unitAfterRoundTrip.hashCode());
+        assertEquals(KILOGRAM_METRE.getSymbol(), unitAfterRoundTrip.getSymbol());
+        assertEquals(KILOGRAM_METRE.getDimension(), unitAfterRoundTrip.getDimension());
+        assertEquals(KILOGRAM_METRE.getName(), unitAfterRoundTrip.getName());
+        assertEquals(KILOGRAM_METRE.getUnitCount(), unitAfterRoundTrip.getUnitCount());
+        assertEquals(KILOGRAM_METRE.getBaseUnits(), unitAfterRoundTrip.getBaseUnits());
+
+    }
+
+}