Merge pull request #20 from square/jwilson_0323_map_adapter

Map adapter.

moshi/src/main/java/com/squareup/moshi/ArrayJsonAdapter.java

@@ -46,7 +46,7 @@ class ArrayJsonAdapter extends JsonAdapter<Object> {
   }
 
   @Override public Object fromJson(JsonReader reader) throws IOException {
-    List<Object> list = new ArrayList<Object>();
+    List<Object> list = new ArrayList<>();
     reader.beginArray();
     while (reader.hasNext()) {
       list.add(elementAdapter.fromJson(reader));

moshi/src/main/java/com/squareup/moshi/ClassFactory.java

@@ -46,7 +46,7 @@ abstract class ClassFactory<T> {
           return (T) constructor.newInstance(args);
         }
       };
-    } catch (NoSuchMethodException noNoArgsConstructor) {
+    } catch (NoSuchMethodException ignored) {
       // No no-args constructor. Fall back to something more magical...
     }
 
@@ -68,7 +68,7 @@ abstract class ClassFactory<T> {
       };
     } catch (IllegalAccessException e) {
       throw new AssertionError();
-    } catch (ClassNotFoundException | NoSuchMethodException | NoSuchFieldException notJvm) {
+    } catch (ClassNotFoundException | NoSuchMethodException | NoSuchFieldException ignored) {
       // Not the expected version of the Oracle Java library!
     }
 
@@ -95,7 +95,7 @@ abstract class ClassFactory<T> {
       throw new AssertionError();
     } catch (InvocationTargetException e) {
       throw new RuntimeException(e);
-    } catch (NoSuchMethodException notLibcore) {
+    } catch (NoSuchMethodException ignored) {
       // Not the expected version of Dalvik/libcore!
     }
 

moshi/src/main/java/com/squareup/moshi/ClassJsonAdapter.java

@@ -29,7 +29,7 @@ import java.util.TreeMap;
  * of classes in {@code java.*}, {@code javax.*} and {@code android.*} are omitted from both
  * serialization and deserialization unless they are either public or protected.
  */
-final class ClassAdapter<T> extends JsonAdapter<T> {
+final class ClassJsonAdapter<T> extends JsonAdapter<T> {
   public static final JsonAdapter.Factory FACTORY = new JsonAdapter.Factory() {
     @Override public JsonAdapter<?> create(Type type, AnnotatedElement annotations, Moshi moshi) {
       Class<?> rawType = Types.getRawType(type);
@@ -54,7 +54,7 @@ final class ClassAdapter<T> extends JsonAdapter<T> {
       for (Type t = type; t != Object.class; t = Types.getGenericSuperclass(t)) {
         createFieldBindings(moshi, t, fields);
       }
-      return new ClassAdapter<>(classFactory, fields).nullSafe();
+      return new ClassJsonAdapter<>(classFactory, fields).nullSafe();
     }
 
     /** Creates a field binding for each of declared field of {@code type}. */
@@ -103,7 +103,7 @@ final class ClassAdapter<T> extends JsonAdapter<T> {
   private final ClassFactory<T> classFactory;
   private final Map<String, FieldBinding<?>> jsonFields;
 
-  private ClassAdapter(ClassFactory<T> classFactory, Map<String, FieldBinding<?>> jsonFields) {
+  private ClassJsonAdapter(ClassFactory<T> classFactory, Map<String, FieldBinding<?>> jsonFields) {
     this.classFactory = classFactory;
     this.jsonFields = jsonFields;
   }

moshi/src/main/java/com/squareup/moshi/CollectionJsonAdapter.java

@@ -49,7 +49,7 @@ abstract class CollectionJsonAdapter<C extends Collection<T>, T> extends JsonAda
     JsonAdapter<T> elementAdapter = moshi.adapter(elementType);
     return new CollectionJsonAdapter<Collection<T>, T>(elementAdapter) {
       @Override Collection<T> newCollection() {
-        return new ArrayList<T>();
+        return new ArrayList<>();
       }
     };
   }
@@ -59,7 +59,7 @@ abstract class CollectionJsonAdapter<C extends Collection<T>, T> extends JsonAda
     JsonAdapter<T> elementAdapter = moshi.adapter(elementType);
     return new CollectionJsonAdapter<Set<T>, T>(elementAdapter) {
       @Override Set<T> newCollection() {
-        return new LinkedHashSet<T>();
+        return new LinkedHashSet<>();
       }
     };
   }

moshi/src/main/java/com/squareup/moshi/MapJsonAdapter.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2015 Square, 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.squareup.moshi;
+
+import java.io.IOException;
+import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Type;
+import java.util.Map;
+
+/**
+ * Converts maps with string keys to JSON objects.
+ *
+ * TODO: support maps with other key types and convert to/from strings.
+ */
+final class MapJsonAdapter<K, V> extends JsonAdapter<Map<K, V>> {
+  public static final Factory FACTORY = new Factory() {
+    @Override public JsonAdapter<?> create(Type type, AnnotatedElement annotations, Moshi moshi) {
+      Class<?> rawType = Types.getRawType(type);
+      if (rawType != Map.class) return null;
+      Type[] keyAndValue = Types.mapKeyAndValueTypes(type, rawType);
+      if (keyAndValue[0] != String.class) return null;
+      return new MapJsonAdapter<>(moshi, keyAndValue[1]).nullSafe();
+    };
+  };
+
+  private final JsonAdapter<V> valueAdapter;
+
+  public MapJsonAdapter(Moshi moshi, Type valueType) {
+    this.valueAdapter = moshi.adapter(valueType);
+  }
+
+  @Override public void toJson(JsonWriter writer, Map<K, V> map) throws IOException {
+    writer.beginObject();
+    for (Map.Entry<K, V> entry : map.entrySet()) {
+      writer.name((String) entry.getKey());
+      valueAdapter.toJson(writer, entry.getValue());
+    }
+    writer.endObject();
+  }
+
+  @Override public Map<K, V> fromJson(JsonReader reader) throws IOException {
+    LinkedHashTreeMap<K, V> result = new LinkedHashTreeMap<>();
+    reader.beginObject();
+    while (reader.hasNext()) {
+      @SuppressWarnings("unchecked") // Currently 'K' is always 'String'.
+      K name = (K) reader.nextName();
+      V value = valueAdapter.fromJson(reader);
+      V replaced = result.put(name, value);
+      if (replaced != null) {
+        throw new IllegalArgumentException("object property '" + name + "' has multiple values");
+      }
+    }
+    reader.endObject();
+    return result;
+  }
+}

moshi/src/test/java/com/squareup/moshi/ClassJsonAdapterTest.java

@@ -28,7 +28,7 @@ import static com.squareup.moshi.Util.NO_ANNOTATIONS;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.Assert.fail;
 
-public final class ClassAdapterTest {
+public final class ClassJsonAdapterTest {
   private final Moshi moshi = new Moshi.Builder().build();
 
   static class BasicPizza {
@@ -156,12 +156,12 @@ public final class ClassAdapterTest {
 
   @Test public void fieldNameCollision() throws Exception {
     try {
-      ClassAdapter.FACTORY.create(ExtendsBaseA.class, NO_ANNOTATIONS, moshi);
+      ClassJsonAdapter.FACTORY.create(ExtendsBaseA.class, NO_ANNOTATIONS, moshi);
       fail();
     } catch (IllegalArgumentException expected) {
       assertThat(expected).hasMessage("field name collision: 'a' declared by both "
-          + "com.squareup.moshi.ClassAdapterTest$ExtendsBaseA and "
-          + "superclass com.squareup.moshi.ClassAdapterTest$BaseA");
+          + "com.squareup.moshi.ClassJsonAdapterTest$ExtendsBaseA and "
+          + "superclass com.squareup.moshi.ClassJsonAdapterTest$BaseA");
     }
   }
 
@@ -302,17 +302,17 @@ public final class ClassAdapterTest {
 
   @Test public void nonStaticNestedClassNotSupported() throws Exception {
     try {
-      ClassAdapter.FACTORY.create(NonStatic.class, NO_ANNOTATIONS, moshi);
+      ClassJsonAdapter.FACTORY.create(NonStatic.class, NO_ANNOTATIONS, moshi);
       fail();
     } catch (IllegalArgumentException expected) {
       assertThat(expected).hasMessage("cannot serialize non-static nested class "
-          + "com.squareup.moshi.ClassAdapterTest$NonStatic");
+          + "com.squareup.moshi.ClassJsonAdapterTest$NonStatic");
     }
   }
 
   @Test public void platformClassNotSupported() throws Exception {
-    assertThat(ClassAdapter.FACTORY.create(UUID.class, NO_ANNOTATIONS, moshi)).isNull();
-    assertThat(ClassAdapter.FACTORY.create(KeyGenerator.class, NO_ANNOTATIONS, moshi)).isNull();
+    assertThat(ClassJsonAdapter.FACTORY.create(UUID.class, NO_ANNOTATIONS, moshi)).isNull();
+    assertThat(ClassJsonAdapter.FACTORY.create(KeyGenerator.class, NO_ANNOTATIONS, moshi)).isNull();
   }
 
   @Test public void anonymousClassNotSupported() throws Exception {
@@ -322,7 +322,7 @@ public final class ClassAdapterTest {
       }
     };
     try {
-      ClassAdapter.FACTORY.create(c.getClass(), NO_ANNOTATIONS, moshi);
+      ClassJsonAdapter.FACTORY.create(c.getClass(), NO_ANNOTATIONS, moshi);
       fail();
     } catch (IllegalArgumentException expected) {
       assertThat(expected).hasMessage("cannot serialize anonymous class " + c.getClass().getName());
@@ -330,7 +330,7 @@ public final class ClassAdapterTest {
   }
 
   @Test public void interfaceNotSupported() throws Exception {
-    assertThat(ClassAdapter.FACTORY.create(Runnable.class, NO_ANNOTATIONS, moshi)).isNull();
+    assertThat(ClassJsonAdapter.FACTORY.create(Runnable.class, NO_ANNOTATIONS, moshi)).isNull();
   }
 
   static abstract class Abstract {
@@ -338,11 +338,11 @@ public final class ClassAdapterTest {
 
   @Test public void abstractClassNotSupported() throws Exception {
     try {
-      ClassAdapter.FACTORY.create(Abstract.class, NO_ANNOTATIONS, moshi);
+      ClassJsonAdapter.FACTORY.create(Abstract.class, NO_ANNOTATIONS, moshi);
       fail();
     } catch (IllegalArgumentException expected) {
       assertThat(expected).hasMessage("cannot serialize abstract class "
-          + "com.squareup.moshi.ClassAdapterTest$Abstract");
+          + "com.squareup.moshi.ClassJsonAdapterTest$Abstract");
     }
   }
 
@@ -390,7 +390,7 @@ public final class ClassAdapterTest {
 
   private <T> String toJson(Class<T> type, T value) throws IOException {
     @SuppressWarnings("unchecked") // Factory.create returns an adapter that matches its argument.
-    JsonAdapter<T> jsonAdapter = (JsonAdapter<T>) ClassAdapter.FACTORY.create(
+    JsonAdapter<T> jsonAdapter = (JsonAdapter<T>) ClassJsonAdapter.FACTORY.create(
         type, NO_ANNOTATIONS, moshi);
 
     // Wrap in an array to avoid top-level object warnings without going completely lenient.
@@ -408,7 +408,7 @@ public final class ClassAdapterTest {
 
   private <T> T fromJson(Class<T> type, String json) throws IOException {
     @SuppressWarnings("unchecked") // Factory.create returns an adapter that matches its argument.
-    JsonAdapter<T> jsonAdapter = (JsonAdapter<T>) ClassAdapter.FACTORY.create(
+    JsonAdapter<T> jsonAdapter = (JsonAdapter<T>) ClassJsonAdapter.FACTORY.create(
         type, NO_ANNOTATIONS, moshi);
     // Wrap in an array to avoid top-level object warnings without going completely lenient.
     JsonReader jsonReader = new JsonReader("[" + json + "]");

moshi/src/test/java/com/squareup/moshi/MapJsonAdapterTest.java

@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2015 Square, 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.squareup.moshi;
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import okio.Buffer;
+import org.assertj.core.data.MapEntry;
+import org.junit.Test;
+
+import static com.squareup.moshi.Util.NO_ANNOTATIONS;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.fail;
+
+public final class MapJsonAdapterTest {
+  private final Moshi moshi = new Moshi.Builder().build();
+
+  @Test public void map() throws Exception {
+    Map<String, Boolean> map = new LinkedHashMap<>();
+    map.put("a", true);
+    map.put("b", false);
+    map.put("c", null);
+
+    String toJson = toJson(String.class, Boolean.class, map);
+    assertThat(toJson).isEqualTo("{\"a\":true,\"b\":false,\"c\":null}");
+
+    Map<String, Boolean> fromJson = fromJson(
+        String.class, Boolean.class, "{\"a\":true,\"b\":false,\"c\":null}");
+    assertThat(fromJson).containsExactly(
+        MapEntry.entry("a", true), MapEntry.entry("b", false), MapEntry.entry("c", null));
+  }
+
+  @Test public void mapWithNullKeyFailsToEmit() throws Exception {
+    Map<String, Boolean> map = new LinkedHashMap<>();
+    map.put(null, true);
+
+    try {
+      toJson(String.class, Boolean.class, map);
+      fail();
+    } catch (NullPointerException expected) {
+    }
+  }
+
+  @Test public void emptyMap() throws Exception {
+    Map<String, Boolean> map = new LinkedHashMap<>();
+
+    String toJson = toJson(String.class, Boolean.class, map);
+    assertThat(toJson).isEqualTo("{}");
+
+    Map<String, Boolean> fromJson = fromJson(String.class, Boolean.class, "{}");
+    assertThat(fromJson).isEmpty();
+  }
+
+  @Test public void nullMap() throws Exception {
+    JsonAdapter<?> jsonAdapter = mapAdapter(String.class, Boolean.class);
+
+    Buffer buffer = new Buffer();
+    JsonWriter jsonWriter = new JsonWriter(buffer);
+    jsonWriter.setLenient(true);
+    jsonAdapter.toJson(jsonWriter, null);
+    assertThat(buffer.readUtf8()).isEqualTo("null");
+
+    JsonReader jsonReader = new JsonReader("null");
+    jsonReader.setLenient(true);
+    assertThat(jsonAdapter.fromJson(jsonReader)).isEqualTo(null);
+  }
+
+  @Test public void orderIsRetained() throws Exception {
+    Map<String, Integer> map = new LinkedHashMap<>();
+    map.put("c", 1);
+    map.put("a", 2);
+    map.put("d", 3);
+    map.put("b", 4);
+
+    String toJson = toJson(String.class, Integer.class, map);
+    assertThat(toJson).isEqualTo("{\"c\":1,\"a\":2,\"d\":3,\"b\":4}");
+
+    Map<String, Integer> fromJson = fromJson(
+        String.class, Integer.class, "{\"c\":1,\"a\":2,\"d\":3,\"b\":4}");
+    assertThat(new ArrayList<Object>(fromJson.keySet()))
+        .isEqualTo(Arrays.asList("c", "a", "d", "b"));
+  }
+
+  @Test public void duplicatesAreForbidden() throws Exception {
+    try {
+      fromJson(String.class, Integer.class, "{\"c\":1,\"c\":2}");
+      fail();
+    } catch (IllegalArgumentException expected) {
+      assertThat(expected).hasMessage("object property 'c' has multiple values");
+    }
+  }
+
+  private <K, V> String toJson(Type keyType, Type valueType, Map<K, V> value) throws IOException {
+    JsonAdapter<Map<K, V>> jsonAdapter = mapAdapter(keyType, valueType);
+    Buffer buffer = new Buffer();
+    JsonWriter jsonWriter = new JsonWriter(buffer);
+    jsonWriter.setSerializeNulls(true);
+    jsonAdapter.toJson(jsonWriter, value);
+    return buffer.readUtf8();
+  }
+
+  @SuppressWarnings("unchecked") // It's the caller's responsibility to make sure K and V match.
+  private <K, V> JsonAdapter<Map<K, V>> mapAdapter(Type keyType, Type valueType) {
+    return (JsonAdapter<Map<K, V>>) MapJsonAdapter.FACTORY.create(
+        Types.newParameterizedType(Map.class, keyType, valueType), NO_ANNOTATIONS, moshi);
+  }
+
+  private <K, V> Map<K, V> fromJson(Type keyType, Type valueType, String json) throws IOException {
+    JsonAdapter<Map<K, V>> mapJsonAdapter = mapAdapter(keyType, valueType);
+    return mapJsonAdapter.fromJson(json);
+  }
+}