gson cleanup work

Author: eugenp

gson/.project

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <projectDescription>
-	<name>jackson</name>
+	<name>gson</name>
 	<comment></comment>
 	<projects>
 	</projects>

gson/src/test/java/org/baeldung/gson/serialization/GsonSerializationTest.java

@@ -0,0 +1,27 @@
+package org.baeldung.gson.serialization;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonSerializationContext;
+import com.google.gson.JsonSerializer;
+
+import java.lang.reflect.Type;
+
+public class IgnoringFieldsNotMatchingCriteriaSerializer implements JsonSerializer<SourceClass> {
+    @Override
+    public JsonElement serialize(SourceClass src, Type typeOfSrc, JsonSerializationContext context) {
+        JsonObject jObject = new JsonObject();
+
+        // Criteria: intValue >= 0
+        if (src.getIntValue() >= 0) {
+            String intValue = "intValue";
+            jObject.addProperty(intValue, src.getIntValue());
+        }
+
+        String stringValue = "stringValue";
+        jObject.addProperty(stringValue, src.getStringValue());
+
+        return jObject;
+    }
+    
+}

gson/src/test/java/org/baeldung/gson/serialization/IgnoringFieldsNotMatchingCriteriaSerializer.java

@@ -0,0 +1,93 @@
+package org.baeldung.gson.serialization.test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.lang.reflect.Type;
+import java.util.Collection;
+import java.util.Date;
+
+import org.baeldung.gson.serialization.DifferentNameSerializer;
+import org.baeldung.gson.serialization.IgnoringFieldsNotMatchingCriteriaSerializer;
+import org.baeldung.gson.serialization.IgnoringFieldsSerializer;
+import org.baeldung.gson.serialization.SourceClass;
+import org.junit.Test;
+
+import com.google.common.collect.Lists;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.reflect.TypeToken;
+
+public class GsonSerializationTest {
+
+    @Test
+    public void givenArrayOfObjects_whenSerializing_thenCorrect() {
+        final SourceClass[] sourceArray = { new SourceClass(1, "one"), new SourceClass(2, "two") };
+        final String jsonString = new Gson().toJson(sourceArray);
+
+        // test
+        final String expectedResult = "[{\"intValue\":1,\"stringValue\":\"one\"},{\"intValue\":2,\"stringValue\":\"two\"}]";
+        assertEquals(expectedResult, jsonString);
+    }
+
+    @Test
+    public void givenCollection_whenSerializing_thenCorrect() {
+        final Collection<SourceClass> sourceCollection = Lists.newArrayList(new SourceClass(1, "one"), new SourceClass(2, "two"));
+        final Type sourceCollectionType = new TypeToken<Collection<SourceClass>>() {
+        }.getType();
+        final String jsonCollection = new Gson().toJson(sourceCollection, sourceCollectionType);
+
+        final String expectedResult = "[{\"intValue\":1,\"stringValue\":\"one\"},{\"intValue\":2,\"stringValue\":\"two\"}]";
+        assertEquals(expectedResult, jsonCollection);
+    }
+
+    @Test
+    public void givenUsingCustomSerializer_whenChangingNameOfFieldOnSerializing_thenCorrect() {
+        final SourceClass sourceObject = new SourceClass(7, "seven");
+        final GsonBuilder gsonBuildr = new GsonBuilder();
+        gsonBuildr.registerTypeAdapter(SourceClass.class, new DifferentNameSerializer());
+        final String jsonString = gsonBuildr.create().toJson(sourceObject);
+
+        final String expectedResult = "{\"otherIntValue\":7,\"otherStringValue\":\"seven\"}";
+        assertEquals(expectedResult, jsonString);
+    }
+
+    @Test
+    public void givenIgnoringAField_whenSerializingWithCustomSerializer_thenFieldIgnored() {
+        final SourceClass sourceObject = new SourceClass(7, "seven");
+        final GsonBuilder gsonBuildr = new GsonBuilder();
+        gsonBuildr.registerTypeAdapter(SourceClass.class, new IgnoringFieldsSerializer());
+        final String jsonString = gsonBuildr.create().toJson(sourceObject);
+
+        final String expectedResult = "{\"intValue\":7}";
+        assertEquals(expectedResult, jsonString);
+    }
+
+    @Test
+    public void givenDate_whenSerializing_thenCorrect() {
+        Date sourceDate = new Date(1000000L);
+        Gson gson = new Gson();
+        Type sourceDateType = new TypeToken<Date>() {
+        }.getType();
+        String jsonDate = gson.toJson(sourceDate, sourceDateType);
+        // test
+        System.out.println("jsonDate:\n" + jsonDate);
+        String estimatedResult = "\"Jan 1, 1970 3:16:40 AM\"";
+        assertTrue(jsonDate.equals(estimatedResult));
+    }
+
+    @Test
+    public void givenUsingCustomDeserializer_whenFieldNotMatchesCriteria_thenIgnoringIt() {
+        SourceClass sourceObject = new SourceClass(-1, "minus 1");
+        GsonBuilder gsonBuildr = new GsonBuilder();
+        gsonBuildr.registerTypeAdapter(SourceClass.class, new IgnoringFieldsNotMatchingCriteriaSerializer());
+        Gson gson = gsonBuildr.create();
+        Type sourceObjectType = new TypeToken<SourceClass>() {
+        }.getType();
+        String jsonString = gson.toJson(sourceObject, sourceObjectType);
+        // test
+        String estimatedResult = "{\"stringValue\":\"minus 1\"}";
+        assertEquals(estimatedResult, jsonString);
+    }
+    
+}