Warning fixes

gson/src/main/java/com/google/gson/DefaultDateTypeAdapter.java

@@ -41,38 +41,68 @@
  * @author Inderjeet Singh
  * @author Joel Leitch
  */
-final class DefaultDateTypeAdapter extends TypeAdapter<Date> {
-
+final class DefaultDateTypeAdapter<T extends Date> extends TypeAdapter<T> {
   private static final String SIMPLE_NAME = "DefaultDateTypeAdapter";
 
-  private final Class<? extends Date> dateType;
+  static abstract class DateType<T extends Date> {
+    private DateType() {
+    }
+
+    public static final DateType<Date> DATE = new DateType<Date>() {
+      @Override
+      protected Date deserialize(Date date) {
+        return date;
+      }
+    };
+    public static final DateType<java.sql.Date> SQL_DATE = new DateType<java.sql.Date>() {
+      @Override
+      protected java.sql.Date deserialize(Date date) {
+        return new java.sql.Date(date.getTime());
+      }
+    };
+    public static final DateType<Timestamp> SQL_TIMESTAMP = new DateType<Timestamp>() {
+      @Override
+      protected Timestamp deserialize(Date date) {
+        return new Timestamp(date.getTime());
+      }
+    };
+
+    protected abstract T deserialize(Date date);
+
+    public DefaultDateTypeAdapter<T> createAdapter(String datePattern) {
+      return new DefaultDateTypeAdapter<T>(this, datePattern);
+    }
+
+    public DefaultDateTypeAdapter<T> createAdapter(int style) {
+      return new DefaultDateTypeAdapter<T>(this, style);
+    }
+
+    public DefaultDateTypeAdapter<T> createAdapter(int dateStyle, int timeStyle) {
+      return new DefaultDateTypeAdapter<T>(this, dateStyle, timeStyle);
+    }
+
+    public DefaultDateTypeAdapter<T> createDefaultsAdapter() {
+      return new DefaultDateTypeAdapter<T>(this, DateFormat.DEFAULT, DateFormat.DEFAULT);
+    }
+  }
+
+  private final DateType<T> dateType;
 
   /**
    * List of 1 or more different date formats used for de-serialization attempts.
    * The first of them is used for serialization as well.
    */
   private final List<DateFormat> dateFormats = new ArrayList<DateFormat>();
 
-  DefaultDateTypeAdapter(Class<? extends Date> dateType) {
-    this.dateType = verifyDateType(dateType);
-    dateFormats.add(DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.US));
-    if (!Locale.getDefault().equals(Locale.US)) {
-      dateFormats.add(DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT));
-    }
-    if (JavaVersion.isJava9OrLater()) {
-      dateFormats.add(PreJava9DateFormatProvider.getUSDateTimeFormat(DateFormat.DEFAULT, DateFormat.DEFAULT));
-    }
-  }
-
-  DefaultDateTypeAdapter(Class<? extends Date> dateType, String datePattern) {
+  private DefaultDateTypeAdapter(DateType<T> dateType, String datePattern) {
     this.dateType = verifyDateType(dateType);
     dateFormats.add(new SimpleDateFormat(datePattern, Locale.US));
     if (!Locale.getDefault().equals(Locale.US)) {
       dateFormats.add(new SimpleDateFormat(datePattern));
     }
   }
 
-  DefaultDateTypeAdapter(Class<? extends Date> dateType, int style) {
+  private DefaultDateTypeAdapter(DateType<T> dateType, int style) {
     this.dateType = verifyDateType(dateType);
     dateFormats.add(DateFormat.getDateInstance(style, Locale.US));
     if (!Locale.getDefault().equals(Locale.US)) {
@@ -83,11 +113,7 @@ final class DefaultDateTypeAdapter extends TypeAdapter<Date> {
     }
   }
 
-  public DefaultDateTypeAdapter(int dateStyle, int timeStyle) {
-    this(Date.class, dateStyle, timeStyle);
-  }
-
-  public DefaultDateTypeAdapter(Class<? extends Date> dateType, int dateStyle, int timeStyle) {
+  private DefaultDateTypeAdapter(DateType<T> dateType, int dateStyle, int timeStyle) {
     this.dateType = verifyDateType(dateType);
     dateFormats.add(DateFormat.getDateTimeInstance(dateStyle, timeStyle, Locale.US));
     if (!Locale.getDefault().equals(Locale.US)) {
@@ -98,9 +124,9 @@ public DefaultDateTypeAdapter(Class<? extends Date> dateType, int dateStyle, int
     }
   }
 
-  private static Class<? extends Date> verifyDateType(Class<? extends Date> dateType) {
-    if ( dateType != Date.class && dateType != java.sql.Date.class && dateType != Timestamp.class ) {
-      throw new IllegalArgumentException("Date type must be one of " + Date.class + ", " + Timestamp.class + ", or " + java.sql.Date.class + " but was " + dateType);
+  private static <T extends Date> DateType<T> verifyDateType(DateType<T> dateType) {
+    if (dateType == null) {
+      throw new NullPointerException("dateType == null");
     }
     return dateType;
   }
@@ -120,22 +146,13 @@ public void write(JsonWriter out, Date value) throws IOException {
   }
 
   @Override
-  public Date read(JsonReader in) throws IOException {
+  public T read(JsonReader in) throws IOException {
     if (in.peek() == JsonToken.NULL) {
       in.nextNull();
       return null;
     }
     Date date = deserializeToDate(in.nextString());
-    if (dateType == Date.class) {
-      return date;
-    } else if (dateType == Timestamp.class) {
-      return new Timestamp(date.getTime());
-    } else if (dateType == java.sql.Date.class) {
-      return new java.sql.Date(date.getTime());
-    } else {
-      // This must never happen: dateType is guarded in the primary constructor
-      throw new AssertionError();
-    }
+    return dateType.deserialize(date);
   }
 
   private Date deserializeToDate(String s) {

gson/src/main/java/com/google/gson/GsonBuilder.java

@@ -602,20 +602,19 @@ public Gson create() {
         this.factories, this.hierarchyFactories, factories);
   }
 
-  @SuppressWarnings("unchecked")
   private void addTypeAdaptersForDate(String datePattern, int dateStyle, int timeStyle,
       List<TypeAdapterFactory> factories) {
-    DefaultDateTypeAdapter dateTypeAdapter;
+    DefaultDateTypeAdapter<Date> dateTypeAdapter;
     TypeAdapter<Timestamp> timestampTypeAdapter;
     TypeAdapter<java.sql.Date> javaSqlDateTypeAdapter;
     if (datePattern != null && !"".equals(datePattern.trim())) {
-      dateTypeAdapter = new DefaultDateTypeAdapter(Date.class, datePattern);
-      timestampTypeAdapter = (TypeAdapter) new DefaultDateTypeAdapter(Timestamp.class, datePattern);
-      javaSqlDateTypeAdapter = (TypeAdapter) new DefaultDateTypeAdapter(java.sql.Date.class, datePattern);
+      dateTypeAdapter = DefaultDateTypeAdapter.DateType.DATE.createAdapter(datePattern);
+      timestampTypeAdapter = DefaultDateTypeAdapter.DateType.SQL_TIMESTAMP.createAdapter(datePattern);
+      javaSqlDateTypeAdapter = DefaultDateTypeAdapter.DateType.SQL_DATE.createAdapter(datePattern);
     } else if (dateStyle != DateFormat.DEFAULT && timeStyle != DateFormat.DEFAULT) {
-      dateTypeAdapter = new DefaultDateTypeAdapter(Date.class, dateStyle, timeStyle);
-      timestampTypeAdapter = (TypeAdapter) new DefaultDateTypeAdapter(Timestamp.class, dateStyle, timeStyle);
-      javaSqlDateTypeAdapter = (TypeAdapter) new DefaultDateTypeAdapter(java.sql.Date.class, dateStyle, timeStyle);
+      dateTypeAdapter = DefaultDateTypeAdapter.DateType.DATE.createAdapter(dateStyle, timeStyle);
+      timestampTypeAdapter = DefaultDateTypeAdapter.DateType.SQL_TIMESTAMP.createAdapter(dateStyle, timeStyle);
+      javaSqlDateTypeAdapter = DefaultDateTypeAdapter.DateType.SQL_DATE.createAdapter(dateStyle, timeStyle);
     } else {
       return;
     }

gson/src/main/java/com/google/gson/internal/$Gson$Types.java

@@ -334,11 +334,11 @@ public static Type[] getMapKeyAndValueTypes(Type context, Class<?> contextRawTyp
   }
 
   public static Type resolve(Type context, Class<?> contextRawType, Type toResolve) {
-    return resolve(context, contextRawType, toResolve, new HashSet<TypeVariable>());
+    return resolve(context, contextRawType, toResolve, new HashSet<TypeVariable<?>>());
   }
 
   private static Type resolve(Type context, Class<?> contextRawType, Type toResolve,
-                              Collection<TypeVariable> visitedTypeVariables) {
+                              Collection<TypeVariable<?>> visitedTypeVariables) {
     // this implementation is made a little more complicated in an attempt to avoid object-creation
     while (true) {
       if (toResolve instanceof TypeVariable) {

gson/src/test/java/com/google/gson/DefaultDateTypeAdapterTest.java

@@ -23,6 +23,7 @@
 import java.util.Locale;
 import java.util.TimeZone;
 
+import com.google.gson.DefaultDateTypeAdapter.DateType;
 import com.google.gson.internal.JavaVersion;
 
 import junit.framework.TestCase;
@@ -52,18 +53,18 @@ private void assertFormattingAlwaysEmitsUsLocale(Locale locale) {
       String afterYearLongSep = JavaVersion.isJava9OrLater() ? " at " : " ";
       String utcFull = JavaVersion.isJava9OrLater() ? "Coordinated Universal Time" : "UTC";
       assertFormatted(String.format("Jan 1, 1970%s12:00:00 AM", afterYearSep),
-              new DefaultDateTypeAdapter(Date.class));
-      assertFormatted("1/1/70", new DefaultDateTypeAdapter(Date.class, DateFormat.SHORT));
-      assertFormatted("Jan 1, 1970", new DefaultDateTypeAdapter(Date.class, DateFormat.MEDIUM));
-      assertFormatted("January 1, 1970", new DefaultDateTypeAdapter(Date.class, DateFormat.LONG));
+          DateType.DATE.createDefaultsAdapter());
+      assertFormatted("1/1/70", DateType.DATE.createAdapter(DateFormat.SHORT));
+      assertFormatted("Jan 1, 1970", DateType.DATE.createAdapter(DateFormat.MEDIUM));
+      assertFormatted("January 1, 1970", DateType.DATE.createAdapter(DateFormat.LONG));
       assertFormatted(String.format("1/1/70%s12:00 AM", afterYearSep),
-          new DefaultDateTypeAdapter(DateFormat.SHORT, DateFormat.SHORT));
+          DateType.DATE.createAdapter(DateFormat.SHORT, DateFormat.SHORT));
       assertFormatted(String.format("Jan 1, 1970%s12:00:00 AM", afterYearSep),
-          new DefaultDateTypeAdapter(DateFormat.MEDIUM, DateFormat.MEDIUM));
+          DateType.DATE.createAdapter(DateFormat.MEDIUM, DateFormat.MEDIUM));
       assertFormatted(String.format("January 1, 1970%s12:00:00 AM UTC", afterYearLongSep),
-          new DefaultDateTypeAdapter(DateFormat.LONG, DateFormat.LONG));
+          DateType.DATE.createAdapter(DateFormat.LONG, DateFormat.LONG));
       assertFormatted(String.format("Thursday, January 1, 1970%s12:00:00 AM %s", afterYearLongSep, utcFull),
-          new DefaultDateTypeAdapter(DateFormat.FULL, DateFormat.FULL));
+          DateType.DATE.createAdapter(DateFormat.FULL, DateFormat.FULL));
     } finally {
       TimeZone.setDefault(defaultTimeZone);
       Locale.setDefault(defaultLocale);
@@ -78,21 +79,21 @@ public void testParsingDatesFormattedWithSystemLocale() throws Exception {
     try {
       String afterYearSep = JavaVersion.isJava9OrLater() ? " à " : " ";
       assertParsed(String.format("1 janv. 1970%s00:00:00", afterYearSep),
-              new DefaultDateTypeAdapter(Date.class));
-      assertParsed("01/01/70", new DefaultDateTypeAdapter(Date.class, DateFormat.SHORT));
-      assertParsed("1 janv. 1970", new DefaultDateTypeAdapter(Date.class, DateFormat.MEDIUM));
-      assertParsed("1 janvier 1970", new DefaultDateTypeAdapter(Date.class, DateFormat.LONG));
+          DateType.DATE.createDefaultsAdapter());
+      assertParsed("01/01/70", DateType.DATE.createAdapter(DateFormat.SHORT));
+      assertParsed("1 janv. 1970", DateType.DATE.createAdapter(DateFormat.MEDIUM));
+      assertParsed("1 janvier 1970", DateType.DATE.createAdapter(DateFormat.LONG));
       assertParsed("01/01/70 00:00",
-          new DefaultDateTypeAdapter(DateFormat.SHORT, DateFormat.SHORT));
+          DateType.DATE.createAdapter(DateFormat.SHORT, DateFormat.SHORT));
       assertParsed(String.format("1 janv. 1970%s00:00:00", afterYearSep),
-          new DefaultDateTypeAdapter(DateFormat.MEDIUM, DateFormat.MEDIUM));
+          DateType.DATE.createAdapter(DateFormat.MEDIUM, DateFormat.MEDIUM));
       assertParsed(String.format("1 janvier 1970%s00:00:00 UTC", afterYearSep),
-          new DefaultDateTypeAdapter(DateFormat.LONG, DateFormat.LONG));
+          DateType.DATE.createAdapter(DateFormat.LONG, DateFormat.LONG));
       assertParsed(JavaVersion.isJava9OrLater() ? (JavaVersion.getMajorJavaVersion() <11 ?
                       "jeudi 1 janvier 1970 à 00:00:00 Coordinated Universal Time" :
                       "jeudi 1 janvier 1970 à 00:00:00 Temps universel coordonné") :
                       "jeudi 1 janvier 1970 00 h 00 UTC",
-          new DefaultDateTypeAdapter(DateFormat.FULL, DateFormat.FULL));
+          DateType.DATE.createAdapter(DateFormat.FULL, DateFormat.FULL));
     } finally {
       TimeZone.setDefault(defaultTimeZone);
       Locale.setDefault(defaultLocale);
@@ -105,18 +106,18 @@ public void testParsingDatesFormattedWithUsLocale() throws Exception {
     Locale defaultLocale = Locale.getDefault();
     Locale.setDefault(Locale.US);
     try {
-      assertParsed("Jan 1, 1970 0:00:00 AM", new DefaultDateTypeAdapter(Date.class));
-      assertParsed("1/1/70", new DefaultDateTypeAdapter(Date.class, DateFormat.SHORT));
-      assertParsed("Jan 1, 1970", new DefaultDateTypeAdapter(Date.class, DateFormat.MEDIUM));
-      assertParsed("January 1, 1970", new DefaultDateTypeAdapter(Date.class, DateFormat.LONG));
+      assertParsed("Jan 1, 1970 0:00:00 AM", DateType.DATE.createDefaultsAdapter());
+      assertParsed("1/1/70", DateType.DATE.createAdapter(DateFormat.SHORT));
+      assertParsed("Jan 1, 1970", DateType.DATE.createAdapter(DateFormat.MEDIUM));
+      assertParsed("January 1, 1970", DateType.DATE.createAdapter(DateFormat.LONG));
       assertParsed("1/1/70 0:00 AM",
-          new DefaultDateTypeAdapter(DateFormat.SHORT, DateFormat.SHORT));
+          DateType.DATE.createAdapter(DateFormat.SHORT, DateFormat.SHORT));
       assertParsed("Jan 1, 1970 0:00:00 AM",
-          new DefaultDateTypeAdapter(DateFormat.MEDIUM, DateFormat.MEDIUM));
+          DateType.DATE.createAdapter(DateFormat.MEDIUM, DateFormat.MEDIUM));
       assertParsed("January 1, 1970 0:00:00 AM UTC",
-          new DefaultDateTypeAdapter(DateFormat.LONG, DateFormat.LONG));
+          DateType.DATE.createAdapter(DateFormat.LONG, DateFormat.LONG));
       assertParsed("Thursday, January 1, 1970 0:00:00 AM UTC",
-          new DefaultDateTypeAdapter(DateFormat.FULL, DateFormat.FULL));
+          DateType.DATE.createAdapter(DateFormat.FULL, DateFormat.FULL));
     } finally {
       TimeZone.setDefault(defaultTimeZone);
       Locale.setDefault(defaultLocale);
@@ -131,16 +132,16 @@ public void testFormatUsesDefaultTimezone() throws Exception {
     try {
       String afterYearSep = JavaVersion.isJava9OrLater() ? ", " : " ";
       assertFormatted(String.format("Dec 31, 1969%s4:00:00 PM", afterYearSep),
-              new DefaultDateTypeAdapter(Date.class));
-      assertParsed("Dec 31, 1969 4:00:00 PM", new DefaultDateTypeAdapter(Date.class));
+          DateType.DATE.createDefaultsAdapter());
+      assertParsed("Dec 31, 1969 4:00:00 PM", DateType.DATE.createDefaultsAdapter());
     } finally {
       TimeZone.setDefault(defaultTimeZone);
       Locale.setDefault(defaultLocale);
     }
   }
 
   public void testDateDeserializationISO8601() throws Exception {
-    DefaultDateTypeAdapter adapter = new DefaultDateTypeAdapter(Date.class);
+    DefaultDateTypeAdapter<Date> adapter = DateType.DATE.createDefaultsAdapter();
     assertParsed("1970-01-01T00:00:00.000Z", adapter);
     assertParsed("1970-01-01T00:00Z", adapter);
     assertParsed("1970-01-01T00:00:00+00:00", adapter);
@@ -150,7 +151,7 @@ public void testDateDeserializationISO8601() throws Exception {
 
   public void testDateSerialization() throws Exception {
     int dateStyle = DateFormat.LONG;
-    DefaultDateTypeAdapter dateTypeAdapter = new DefaultDateTypeAdapter(Date.class, dateStyle);
+    DefaultDateTypeAdapter<Date> dateTypeAdapter = DateType.DATE.createAdapter(dateStyle);
     DateFormat formatter = DateFormat.getDateInstance(dateStyle, Locale.US);
     Date currentDate = new Date();
 
@@ -160,41 +161,40 @@ public void testDateSerialization() throws Exception {
 
   public void testDatePattern() throws Exception {
     String pattern = "yyyy-MM-dd";
-    DefaultDateTypeAdapter dateTypeAdapter = new DefaultDateTypeAdapter(Date.class, pattern);
+    DefaultDateTypeAdapter<Date> dateTypeAdapter = DateType.DATE.createAdapter(pattern);
     DateFormat formatter = new SimpleDateFormat(pattern);
     Date currentDate = new Date();
 
     String dateString = dateTypeAdapter.toJson(currentDate);
     assertEquals(toLiteral(formatter.format(currentDate)), dateString);
   }
 
-  @SuppressWarnings("unused")
   public void testInvalidDatePattern() throws Exception {
     try {
-      new DefaultDateTypeAdapter(Date.class, "I am a bad Date pattern....");
+      DateType.DATE.createAdapter("I am a bad Date pattern....");
       fail("Invalid date pattern should fail.");
     } catch (IllegalArgumentException expected) { }
   }
 
   public void testNullValue() throws Exception {
-    DefaultDateTypeAdapter adapter = new DefaultDateTypeAdapter(Date.class);
+    DefaultDateTypeAdapter<Date> adapter = DateType.DATE.createDefaultsAdapter();
     assertNull(adapter.fromJson("null"));
     assertEquals("null", adapter.toJson(null));
   }
 
   public void testUnexpectedToken() throws Exception {
     try {
-      DefaultDateTypeAdapter adapter = new DefaultDateTypeAdapter(Date.class);
+      DefaultDateTypeAdapter<Date> adapter = DateType.DATE.createDefaultsAdapter();
       adapter.fromJson("{}");
       fail("Unexpected token should fail.");
     } catch (IllegalStateException expected) { }
   }
 
-  private void assertFormatted(String formatted, DefaultDateTypeAdapter adapter) {
+  private void assertFormatted(String formatted, DefaultDateTypeAdapter<Date> adapter) {
     assertEquals(toLiteral(formatted), adapter.toJson(new Date(0)));
   }
 
-  private void assertParsed(String date, DefaultDateTypeAdapter adapter) throws IOException {
+  private void assertParsed(String date, DefaultDateTypeAdapter<Date> adapter) throws IOException {
     assertEquals(date, new Date(0), adapter.fromJson(toLiteral(date)));
     assertEquals("ISO 8601", new Date(0), adapter.fromJson(toLiteral("1970-01-01T00:00:00Z")));
   }

gson/src/test/java/com/google/gson/functional/CollectionTest.java

@@ -37,7 +37,6 @@
 import com.google.gson.JsonPrimitive;
 import com.google.gson.JsonSerializationContext;
 import com.google.gson.JsonSerializer;
-import com.google.gson.common.MoreAsserts;
 import com.google.gson.common.TestTypes.BagOfPrimitives;
 import com.google.gson.reflect.TypeToken;
 

gson/src/test/java/com/google/gson/functional/TreeTypeAdaptersTest.java

@@ -172,6 +172,7 @@ private static class HistoryCourse {
     int numClasses;
   }
 
+  @SafeVarargs
   private static <T> List<T> createList(T ...items) {
     return Arrays.asList(items);
   }

gson/src/test/java/com/google/gson/internal/LinkedHashTreeMapTest.java

@@ -280,6 +280,7 @@ private String toString(Node<?, ?> root) {
     }
   }
 
+  @SafeVarargs
   private <T> void assertIterationOrder(Iterable<T> actual, T... expected) {
     ArrayList<T> actualList = new ArrayList<T>();
     for (T t : actual) {

gson/src/test/java/com/google/gson/internal/LinkedTreeMapTest.java

@@ -140,6 +140,7 @@ public void testEqualsAndHashCode() throws Exception {
     MoreAsserts.assertEqualsAndHashCode(map1, map2);
   }
 
+  @SafeVarargs
   private <T> void assertIterationOrder(Iterable<T> actual, T... expected) {
     ArrayList<T> actualList = new ArrayList<T>();
     for (T t : actual) {