From 109915d93a2b36c26b49c0fabb1947a5a892cb25 Mon Sep 17 00:00:00 2001 From: Inderjeet Singh Date: Sat, 3 Oct 2015 02:01:16 -0700 Subject: [PATCH] Implemented support for multiple values for SerializedName annotation. --- gson/pom.xml | 2 +- .../gson/annotations/SerializedName.java | 37 +++++++++---- .../bind/ReflectiveTypeAdapterFactory.java | 47 +++++++++++----- .../gson/internal/bind/TypeAdapters.java | 3 ++ .../gson/functional/SerializedNameTest.java | 54 +++++++++++++++++++ 5 files changed, 118 insertions(+), 25 deletions(-) create mode 100644 gson/src/test/java/com/google/gson/functional/SerializedNameTest.java diff --git a/gson/pom.xml b/gson/pom.xml index a2d370a1..3ddcbc07 100644 --- a/gson/pom.xml +++ b/gson/pom.xml @@ -3,7 +3,7 @@ com.google.code.gson gson jar - 2.3.2-SNAPSHOT + 2.4-SNAPSHOT 2008 Gson diff --git a/gson/src/main/java/com/google/gson/annotations/SerializedName.java b/gson/src/main/java/com/google/gson/annotations/SerializedName.java index c607bd56..06c0a14c 100644 --- a/gson/src/main/java/com/google/gson/annotations/SerializedName.java +++ b/gson/src/main/java/com/google/gson/annotations/SerializedName.java @@ -33,13 +33,15 @@ import java.lang.annotation.Target; * *

Here is an example of how this annotation is meant to be used:

* 
- * public class SomeClassWithFields {
- *   @SerializedName("name") private final String someField;
- *   private final String someOtherField;
+ * public class MyClass {
+ *   @SerializedName("name") String a;
+ *   @SerializedName(value="name1", alternate={"name2", "name3"}) String b;
+ *   String c;
  *
- *   public SomeClassWithFields(String a, String b) {
- *     this.someField = a;
- *     this.someOtherField = b;
+ *   public MyClass(String a, String b, String c) {
+ *     this.a = a;
+ *     this.b = b;
+ *     this.c = c;
  *   }
  * }
  *
@@ -47,16 +49,27 @@ import java.lang.annotation.Target; *

The following shows the output that is generated when serializing an instance of the * above example class:

* 
- * SomeClassWithFields objectToSerialize = new SomeClassWithFields("a", "b");
+ * MyClass target = new MyClass("v1", "v2", "v3");
  * Gson gson = new Gson();
- * String jsonRepresentation = gson.toJson(objectToSerialize);
- * System.out.println(jsonRepresentation);
+ * String json = gson.toJson(target);
+ * System.out.println(json);
  *
  * ===== OUTPUT =====
- * {"name":"a","someOtherField":"b"}
+ * {"name":"v1","name1":"v2","c":"v3"}
  *
* *

NOTE: The value you specify in this annotation must be a valid JSON field name.

+ * While deserializing, all values specified in the annotation will be deserialized into the field. + * For example: + * 
+ *   MyClass target = gson.fromJson("{'name1':'v1'}", MyClass.class);
+ *   assertEquals("v1", target.b);
+ *   target = gson.fromJson("{'name2':'v2'}", MyClass.class);
+ *   assertEquals("v2", target.b);
+ *   target = gson.fromJson("{'name3':'v3'}", MyClass.class);
+ *   assertEquals("v3", target.b);
+ *
+ * Note that MyClass.b is now deserialized from either name1, name2 or name3. * * @see com.google.gson.FieldNamingPolicy * @@ -68,7 +81,9 @@ import java.lang.annotation.Target; public @interface SerializedName { /** - * @return the desired name of the field when it is serialized + * @return the desired names of the field when it is deserialized or serialized. All of the specified names will be deserialized from. + * The specified first name is what is used for serialization. */ String value(); + String[] alternate() default {}; } diff --git a/gson/src/main/java/com/google/gson/internal/bind/ReflectiveTypeAdapterFactory.java b/gson/src/main/java/com/google/gson/internal/bind/ReflectiveTypeAdapterFactory.java index feda3b87..3957c369 100644 --- a/gson/src/main/java/com/google/gson/internal/bind/ReflectiveTypeAdapterFactory.java +++ b/gson/src/main/java/com/google/gson/internal/bind/ReflectiveTypeAdapterFactory.java @@ -16,6 +16,16 @@ package com.google.gson.internal.bind; +import static com.google.gson.internal.bind.JsonAdapterAnnotationTypeAdapterFactory.getTypeAdapter; + +import java.io.IOException; +import java.lang.reflect.Field; +import java.lang.reflect.Type; +import java.util.LinkedHashMap; +import java.util.LinkedList; +import java.util.List; +import java.util.Map; + import com.google.gson.FieldNamingStrategy; import com.google.gson.Gson; import com.google.gson.JsonSyntaxException; @@ -32,13 +42,6 @@ import com.google.gson.reflect.TypeToken; import com.google.gson.stream.JsonReader; import com.google.gson.stream.JsonToken; import com.google.gson.stream.JsonWriter; -import java.io.IOException; -import java.lang.reflect.Field; -import java.lang.reflect.Type; -import java.util.LinkedHashMap; -import java.util.Map; - -import static com.google.gson.internal.bind.JsonAdapterAnnotationTypeAdapterFactory.getTypeAdapter; /** * Type adapter that reflects over the fields and methods of a class. @@ -63,13 +66,24 @@ public final class ReflectiveTypeAdapterFactory implements TypeAdapterFactory { return !excluder.excludeClass(f.getType(), serialize) && !excluder.excludeField(f, serialize); } - private String getFieldName(Field f) { + /** first element holds the default name */ + private List getFieldNames(Field f) { return getFieldName(fieldNamingPolicy, f); } - static String getFieldName(FieldNamingStrategy fieldNamingPolicy, Field f) { + /** first element holds the default name */ + static List getFieldName(FieldNamingStrategy fieldNamingPolicy, Field f) { SerializedName serializedName = f.getAnnotation(SerializedName.class); - return serializedName == null ? fieldNamingPolicy.translateName(f) : serializedName.value(); + List fieldNames = new LinkedList(); + if (serializedName == null) { + fieldNames.add(fieldNamingPolicy.translateName(f)); + } else { + fieldNames.add(serializedName.value()); + for (String alternate : serializedName.alternate()) { + fieldNames.add(alternate); + } + } + return fieldNames; } public TypeAdapter create(Gson gson, final TypeToken type) { @@ -139,9 +153,16 @@ public final class ReflectiveTypeAdapterFactory implements TypeAdapterFactory { } field.setAccessible(true); Type fieldType = $Gson$Types.resolve(type.getType(), raw, field.getGenericType()); - BoundField boundField = createBoundField(context, field, getFieldName(field), - TypeToken.get(fieldType), serialize, deserialize); - BoundField previous = result.put(boundField.name, boundField); + List fieldNames = getFieldNames(field); + BoundField previous = null; + for (int i = 0; i < fieldNames.size(); ++i) { + String name = fieldNames.get(i); + if (i != 0) serialize = false; // only serialize the default name + BoundField boundField = createBoundField(context, field, name, + TypeToken.get(fieldType), serialize, deserialize); + BoundField replaced = result.put(name, boundField); + if (previous == null) previous = replaced; + } if (previous != null) { throw new IllegalArgumentException(declaredType + " declares multiple JSON fields named " + previous.name); diff --git a/gson/src/main/java/com/google/gson/internal/bind/TypeAdapters.java b/gson/src/main/java/com/google/gson/internal/bind/TypeAdapters.java index a8465fcb..ec7ceb4f 100644 --- a/gson/src/main/java/com/google/gson/internal/bind/TypeAdapters.java +++ b/gson/src/main/java/com/google/gson/internal/bind/TypeAdapters.java @@ -727,6 +727,9 @@ public final class TypeAdapters { SerializedName annotation = classOfT.getField(name).getAnnotation(SerializedName.class); if (annotation != null) { name = annotation.value(); + for (String alternate : annotation.alternate()) { + nameToConstant.put(alternate, constant); + } } nameToConstant.put(name, constant); constantToName.put(constant, name); diff --git a/gson/src/test/java/com/google/gson/functional/SerializedNameTest.java b/gson/src/test/java/com/google/gson/functional/SerializedNameTest.java new file mode 100644 index 00000000..38ad8242 --- /dev/null +++ b/gson/src/test/java/com/google/gson/functional/SerializedNameTest.java @@ -0,0 +1,54 @@ +/* + * Copyright (C) 2015 Google Inc. + * + * 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 com.google.gson.functional; + +import com.google.gson.Gson; +import com.google.gson.annotations.SerializedName; + +import junit.framework.TestCase; + +public final class SerializedNameTest extends TestCase { + private final Gson gson = new Gson(); + + public void testFirstNameIsChosenForSerialization() { + MyClass target = new MyClass("v1", "v2"); + // Ensure name1 occurs exactly once, and name2 and name3 dont appear + assertEquals("{\"name\":\"v1\",\"name1\":\"v2\"}", gson.toJson(target)); + } + + public void testMultipleNamesDeserializedCorrectly() { + assertEquals("v1", gson.fromJson("{'name':'v1'}", MyClass.class).a); + + // Both name1 and name2 gets deserialized to b + assertEquals("v11", gson.fromJson("{'name1':'v11'}", MyClass.class).b); + assertEquals("v2", gson.fromJson("{'name2':'v2'}", MyClass.class).b); + assertEquals("v3", gson.fromJson("{'name3':'v3'}", MyClass.class).b); + } + + public void testMultipleNamesInTheSameString() { + // The last value takes precedence + assertEquals("v3", gson.fromJson("{'name1':'v1','name2':'v2','name3':'v3'}", MyClass.class).b); + } + + private static final class MyClass { + @SerializedName("name") String a; + @SerializedName(value="name1", alternate={"name2", "name3"}) String b; + MyClass(String a, String b) { + this.a = a; + this.b = b; + } + } +}