Merge pull request #5833 from f41thful/BAEL-2412

BAEL-2412

gson/src/main/java/org/baeldung/gson/primitives/models/BooleanExample.java

@@ -0,0 +1,9 @@
+package org.baeldung.gson.primitives.models;
+
+public class BooleanExample {
+    public boolean value;
+
+    public String toString() {
+        return "{boolean: " + value + "}";
+    }
+}

gson/src/main/java/org/baeldung/gson/primitives/models/ByteExample.java

@@ -0,0 +1,9 @@
+package org.baeldung.gson.primitives.models;
+
+public class ByteExample {
+    public byte value = (byte) 1;
+
+    public String toString() {
+        return "{byte: " + value + "}";
+    }
+}

gson/src/main/java/org/baeldung/gson/primitives/models/CharExample.java

@@ -0,0 +1,9 @@
+package org.baeldung.gson.primitives.models;
+
+public class CharExample {
+    public char value;
+
+    public String toString() {
+        return "{char: " + value + "}";
+    }
+}

gson/src/main/java/org/baeldung/gson/primitives/models/DoubleExample.java

@@ -0,0 +1,9 @@
+package org.baeldung.gson.primitives.models;
+
+public class DoubleExample {
+    public double value;
+
+    public String toString() {
+        return "{float: " + value + "}";
+    }
+}

gson/src/main/java/org/baeldung/gson/primitives/models/FloatExample.java

@@ -0,0 +1,9 @@
+package org.baeldung.gson.primitives.models;
+
+public class FloatExample {
+    public float value;
+
+    public String toString() {
+        return "{float: " + value + "}";
+    }
+}

gson/src/main/java/org/baeldung/gson/primitives/models/InfinityValuesExample.java

@@ -0,0 +1,6 @@
+package org.baeldung.gson.primitives.models;
+
+public class InfinityValuesExample {
+    public float negativeInfinity;
+    public float positiveInfinity;
+}

gson/src/main/java/org/baeldung/gson/primitives/models/LongExample.java

@@ -0,0 +1,9 @@
+package org.baeldung.gson.primitives.models;
+
+public class LongExample {
+    public long value = 1;
+
+    public String toString() {
+        return "{byte: " + value + "}";
+    }
+}

gson/src/main/java/org/baeldung/gson/primitives/models/PrimitiveBundle.java

@@ -0,0 +1,19 @@
+package org.baeldung.gson.primitives.models;
+
+public class PrimitiveBundle {
+    public byte byteValue;
+    public short shortValue;
+    public int intValue;
+    public long longValue;
+    public float floatValue;
+    public double doubleValue;
+    public boolean booleanValue;
+    public char charValue;
+
+    public String toString() {
+        return "{" + "byte: " + byteValue + ", " + "short: " + shortValue + ", "
+            + "int: " + intValue + ", " + "long: " + longValue + ", "
+            + "float: " + floatValue + ", " + "double: " + doubleValue + ", "
+            + "boolean: " + booleanValue + ", " + "char: " + charValue + "}";
+    }
+}

gson/src/main/java/org/baeldung/gson/primitives/models/PrimitiveBundleInitialized.java

@@ -0,0 +1,18 @@
+package org.baeldung.gson.primitives.models;
+
+public class PrimitiveBundleInitialized {
+    // @formatter:off
+    public byte byteValue       = (byte) 1;
+    public short shortValue     = (short) 1;
+    public int intValue         = 1;
+    public long longValue       = 1L;
+    public float floatValue     = 1.0f;
+    public double doubleValue   = 1;
+    // @formatter:on
+
+    public String toString() {
+        return "{" + "byte: " + byteValue + ", " + "short: " + shortValue + ", "
+            + "int: " + intValue + ", " + "long: " + longValue + ", "
+            + "float: " + floatValue + ", " + "double: " + doubleValue + "}";
+    }
+}

gson/src/test/java/org/baeldung/gson/primitives/PrimitiveValuesUnitTest.java

@@ -0,0 +1,248 @@
+package org.baeldung.gson.primitives;
+
+import com.google.gson.*;
+import org.baeldung.gson.primitives.models.*;
+import org.junit.Test;
+
+import java.lang.reflect.Type;
+
+import static junit.framework.TestCase.*;
+
+public class PrimitiveValuesUnitTest {
+    @Test public void whenSerializingToJSON_thenShouldCreateJSON() {
+        PrimitiveBundle primitiveBundle = new PrimitiveBundle();
+
+        // @formatter:off
+        primitiveBundle.byteValue    = (byte) 0x00001111;
+        primitiveBundle.shortValue   = (short) 3;
+        primitiveBundle.intValue     = 3;
+        primitiveBundle.longValue    = 3;
+        primitiveBundle.floatValue   = 3.5f;
+        primitiveBundle.doubleValue  = 3.5;
+        primitiveBundle.booleanValue = true;
+        primitiveBundle.charValue    = 'a';
+        // @formatter:on
+
+        Gson gson = new Gson();
+
+        String expected = "{\"byteValue\":17,\"shortValue\":3,\"intValue\":3,"
+            + "\"longValue\":3,\"floatValue\":3.5" + ",\"doubleValue\":3.5"
+            + ",\"booleanValue\":true,\"charValue\":\"a\"}";
+
+        assertEquals(expected, gson.toJson(primitiveBundle));
+    }
+
+    @Test(expected = IllegalArgumentException.class) public void
+    whenSerializingInfinity_thenShouldRaiseAnException() {
+        InfinityValuesExample model = new InfinityValuesExample();
+        model.negativeInfinity = Float.NEGATIVE_INFINITY;
+        model.positiveInfinity = Float.POSITIVE_INFINITY;
+
+        Gson gson = new Gson();
+
+        gson.toJson(model);
+    }
+
+    @Test(expected = IllegalArgumentException.class) public void
+        whenSerializingNaN_thenShouldRaiseAnException() {
+        FloatExample model = new FloatExample();
+        model.value = Float.NaN;
+
+        Gson gson = new Gson();
+        gson.toJson(model);
+    }
+
+    @Test public void whenDeserializingFromJSON_thenShouldParseTheValueInTheString() {
+        String json = "{\"byteValue\": 17, \"shortValue\": 3, \"intValue\": 3, "
+            + "\"longValue\": 3, \"floatValue\": 3.5" + ", \"doubleValue\": 3.5"
+            + ", \"booleanValue\": true, \"charValue\": \"a\"}";
+
+        Gson gson = new Gson();
+        PrimitiveBundle model = gson.fromJson(json, PrimitiveBundle.class);
+
+        // @formatter:off
+        assertEquals(17,  model.byteValue);
+        assertEquals(3,   model.shortValue);
+        assertEquals(3,   model.intValue);
+        assertEquals(3,   model.longValue);
+        assertEquals(3.5, model.floatValue, 0.0001);
+        assertEquals(3.5, model.doubleValue, 0.0001);
+        assertTrue(       model.booleanValue);
+        assertEquals('a', model.charValue);
+        // @formatter:on
+    }
+
+    @Test public void whenDeserializingHighPrecissionNumberIntoFloat_thenShouldPerformRounding() {
+        String json = "{\"value\": 12.123425589123456}";
+        Gson gson = new Gson();
+        FloatExample model = gson.fromJson(json, FloatExample.class);
+        assertEquals(12.123426f, model.value, 0.000001);
+    }
+
+    @Test public void whenDeserializingHighPrecissiongNumberIntoDouble_thenShouldPerformRounding() {
+        String json = "{\"value\": 12.123425589123556}";
+        Gson gson = new Gson();
+        DoubleExample model = gson.fromJson(json, DoubleExample.class);
+        assertEquals(12.123425589124f, model.value, 0.000001);
+    }
+
+
+    @Test public void whenDeserializingValueThatOverflows_thenShouldOverflowSilently() {
+        Gson gson = new Gson();
+        String json = "{\"value\": \"300\"}";
+        ByteExample model = gson.fromJson(json, ByteExample.class);
+
+        assertEquals(44, model.value);
+    }
+
+    @Test public void whenDeserializingRealIntoByte_thenShouldRaiseAnException() {
+        Gson gson = new Gson();
+        String json = "{\"value\": 2.3}";
+        try {
+            gson.fromJson(json, ByteExample.class);
+        } catch (Exception ex) {
+            assertTrue(ex instanceof JsonSyntaxException);
+            assertTrue(ex.getCause() instanceof NumberFormatException);
+            return;
+        }
+
+        fail();
+    }
+
+    @Test public void whenDeserializingRealIntoLong_thenShouldRaiseAnException() {
+        Gson gson = new Gson();
+        String json = "{\"value\": 2.3}";
+        try {
+            gson.fromJson(json, LongExample.class);
+        } catch (Exception ex) {
+            assertTrue(ex instanceof JsonSyntaxException);
+            assertTrue(ex.getCause() instanceof NumberFormatException);
+            return;
+        }
+
+        fail();
+    }
+
+    @Test public void whenDeserializingRealWhoseDecimalPartIs0_thenShouldParseItCorrectly() {
+        Gson gson = new Gson();
+        String json = "{\"value\": 2.0}";
+        LongExample model = gson.fromJson(json, LongExample.class);
+        assertEquals(2, model.value);
+    }
+
+    @Test public void whenDeserializingUnicodeChar_thenShouldParseItCorrectly() {
+        Gson gson = new Gson();
+        String json = "{\"value\": \"\\u00AE\"}";
+        CharExample model = gson.fromJson(json, CharExample.class);
+
+        assertEquals('\u00AE', model.value);
+    }
+
+    @Test public void whenDeserializingNullValues_thenShouldIgnoreThoseFields() {
+        Gson gson = new Gson();
+        // @formatter:off
+        String json = "{\"byteValue\": null, \"shortValue\": null, "
+            + "\"intValue\": null, " + "\"longValue\": null, \"floatValue\": null"
+            + ", \"doubleValue\": null}";
+        // @formatter:on
+        PrimitiveBundleInitialized model = gson.fromJson(json,
+            PrimitiveBundleInitialized.class);
+
+        assertEquals(1, model.byteValue);
+        assertEquals(1, model.shortValue);
+        assertEquals(1, model.intValue);
+        assertEquals(1, model.longValue);
+        assertEquals(1, model.floatValue, 0.0001);
+        assertEquals(1, model.doubleValue, 0.0001);
+    }
+
+    @Test(expected = JsonSyntaxException.class) public void
+    whenDeserializingTheEmptyString_thenShouldRaiseAnException() {
+        Gson gson = new Gson();
+        // @formatter:off
+        String json = "{\"byteValue\": \"\", \"shortValue\": \"\", "
+            + "\"intValue\": \"\", " + "\"longValue\": \"\", \"floatValue\": \"\""
+            + ", \"doubleValue\": \"\"" + ", \"booleanValue\": \"\"}";
+        // @formatter:on
+        gson.fromJson(json, PrimitiveBundleInitialized.class);
+    }
+
+    @Test public void whenDeserializingTheEmptyStringIntoChar_thenShouldHaveTheEmtpyChar() {
+        Gson gson = new Gson();
+        // @formatter:off
+        String json = "{\"charValue\": \"\"}";
+        // @formatter:on
+        CharExample model = gson.fromJson(json, CharExample.class);
+
+        assertEquals(Character.MIN_VALUE, model.value);
+    }
+
+    @Test public void whenDeserializingValidValueAppearingInAString_thenShouldParseTheValue() {
+        Gson gson = new Gson();
+        // @formatter:off
+        String json = "{\"byteValue\": \"15\", \"shortValue\": \"15\", "
+            + "\"intValue\": \"15\", " + "\"longValue\": \"15\", \"floatValue\": \"15.0\""
+            + ", \"doubleValue\": \"15.0\"}";
+        // @formatter:on
+        PrimitiveBundleInitialized model = gson.fromJson(json,
+            PrimitiveBundleInitialized.class);
+
+        assertEquals(15, model.byteValue);
+        assertEquals(15, model.shortValue);
+        assertEquals(15, model.intValue);
+        assertEquals(15, model.longValue);
+        assertEquals(15, model.floatValue, 0.0001);
+        assertEquals(15, model.doubleValue, 0.0001);
+    }
+
+    @Test public void whenDeserializingABooleanFrom0Or1Integer_thenShouldRaiseAnException() {
+        String json = "{\"value\": 1}";
+        Gson gson = new Gson();
+
+        try {
+            gson.fromJson(json, BooleanExample.class);
+        } catch (Exception ex) {
+            assertTrue(ex instanceof JsonSyntaxException);
+            assertTrue(ex.getCause() instanceof IllegalStateException);
+            return;
+        }
+
+        fail();
+    }
+
+    @Test public void whenDeserializingWithCustomDeserializerABooleanFrom0Or1Integer_thenShouldWork() {
+        String json = "{\"value\": 1}";
+        GsonBuilder builder = new GsonBuilder();
+        builder.registerTypeAdapter(BooleanExample.class,
+            new BooleanAs2ValueIntegerDeserializer());
+
+        Gson gson = builder.create();
+
+        BooleanExample model = gson.fromJson(json, BooleanExample.class);
+
+        assertTrue(model.value);
+    }
+
+    // @formatter:off
+    static class BooleanAs2ValueIntegerDeserializer implements JsonDeserializer<BooleanExample> {
+        @Override public BooleanExample deserialize(
+            JsonElement jsonElement,
+            Type type,
+            JsonDeserializationContext jsonDeserializationContext) throws JsonParseException {
+
+            BooleanExample model = new BooleanExample();
+            int value = jsonElement.getAsJsonObject().getAsJsonPrimitive("value").getAsInt();
+            if (value == 0) {
+                model.value = false;
+            } else if (value == 1) {
+                model.value = true;
+            } else {
+                throw new JsonParseException("Unexpected value. Trying to deserialize "
+                    + "a boolean from an integer different than 0 and 1.");
+            }
+
+            return model;
+        }
+    }
+    // @formatter:on
+}