Code cleanup

extras/src/main/java/com/google/gson/graph/GraphAdapterBuilder.java

@@ -298,7 +298,7 @@ void write(JsonWriter out) throws IOException {
     }
 
     @SuppressWarnings("unchecked")
-    void read(Graph graph) throws IOException {
+    void read(Graph graph) {
       if (graph.nextCreate != null) {
         throw new IllegalStateException("Unexpected recursive call to read() for " + id);
       }

extras/src/main/java/com/google/gson/typeadapters/UtcDateTypeAdapter.java

@@ -19,15 +19,12 @@
 import java.io.IOException;
 import java.text.ParseException;
 import java.text.ParsePosition;
-import java.util.Calendar;
-import java.util.Date;
-import java.util.GregorianCalendar;
-import java.util.Locale;
-import java.util.TimeZone;
+import java.util.*;
 
 import com.google.gson.JsonParseException;
 import com.google.gson.TypeAdapter;
 import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonToken;
 import com.google.gson.stream.JsonWriter;
 
 public final class UtcDateTypeAdapter extends TypeAdapter<Date> {
@@ -46,16 +43,14 @@ public void write(JsonWriter out, Date date) throws IOException {
   @Override
   public Date read(JsonReader in) throws IOException {
     try {
-      switch (in.peek()) {
-      case NULL:
-        in.nextNull();
-        return null;
-      default:
+        if (Objects.requireNonNull(in.peek()) == JsonToken.NULL) {
+            in.nextNull();
+            return null;
+        }
         String date = in.nextString();
         // Instead of using iso8601Format.parse(value), we use Jackson's date parsing
         // This is because Android doesn't support XXX because it is JDK 1.6
         return parse(date, new ParsePosition(0));
-      }
     } catch (ParseException e) {
       throw new JsonParseException(e);
     }

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

@@ -843,9 +843,7 @@ public void toJson(Object src, Type typeOfSrc, JsonWriter writer) throws JsonIOE
     } catch (IOException e) {
       throw new JsonIOException(e);
     } catch (AssertionError e) {
-      AssertionError error = new AssertionError("AssertionError (GSON " + GsonBuildConfig.VERSION + "): " + e.getMessage());
-      error.initCause(e);
-      throw error;
+      throw new AssertionError("AssertionError (GSON " + GsonBuildConfig.VERSION + "): " + e.getMessage(), e);
     } finally {
       writer.setLenient(oldLenient);
       writer.setHtmlSafe(oldHtmlSafe);
@@ -948,9 +946,7 @@ public void toJson(JsonElement jsonElement, JsonWriter writer) throws JsonIOExce
     } catch (IOException e) {
       throw new JsonIOException(e);
     } catch (AssertionError e) {
-      AssertionError error = new AssertionError("AssertionError (GSON " + GsonBuildConfig.VERSION + "): " + e.getMessage());
-      error.initCause(e);
-      throw error;
+      throw new AssertionError("AssertionError (GSON " + GsonBuildConfig.VERSION + "): " + e.getMessage(), e);
     } finally {
       writer.setLenient(oldLenient);
       writer.setHtmlSafe(oldHtmlSafe);
@@ -1228,8 +1224,7 @@ public <T> T fromJson(JsonReader reader, TypeToken<T> typeOfT) throws JsonIOExce
       reader.peek();
       isEmpty = false;
       TypeAdapter<T> typeAdapter = getAdapter(typeOfT);
-      T object = typeAdapter.read(reader);
-      return object;
+      return typeAdapter.read(reader);
     } catch (EOFException e) {
       /*
        * For compatibility with JSON 1.5 and earlier, we return null for empty
@@ -1245,9 +1240,7 @@ public <T> T fromJson(JsonReader reader, TypeToken<T> typeOfT) throws JsonIOExce
       // TODO(inder): Figure out whether it is indeed right to rethrow this as JsonSyntaxException
       throw new JsonSyntaxException(e);
     } catch (AssertionError e) {
-      AssertionError error = new AssertionError("AssertionError (GSON " + GsonBuildConfig.VERSION + "): " + e.getMessage());
-      error.initCause(e);
-      throw error;
+      throw new AssertionError("AssertionError (GSON " + GsonBuildConfig.VERSION + "): " + e.getMessage(), e);
     } finally {
       reader.setLenient(oldLenient);
     }
@@ -1381,11 +1374,9 @@ private TypeAdapter<T> delegate() {
 
   @Override
   public String toString() {
-    return new StringBuilder("{serializeNulls:")
-        .append(serializeNulls)
-        .append(",factories:").append(factories)
-        .append(",instanceCreators:").append(constructorConstructor)
-        .append("}")
-        .toString();
+    return "{serializeNulls:" + serializeNulls +
+            ",factories:" + factories +
+            ",instanceCreators:" + constructorConstructor +
+            "}";
   }
 }

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

@@ -28,12 +28,7 @@
 import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
 import java.lang.reflect.WildcardType;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.NoSuchElementException;
-import java.util.Properties;
+import java.util.*;
 
 /**
  * Static methods for working with types.
@@ -167,7 +162,7 @@ public static Class<?> getRawType(Type type) {
   }
 
   private static boolean equal(Object a, Object b) {
-    return a == b || (a != null && a.equals(b));
+    return Objects.equals(a, b);
   }
 
   /**

gson/src/main/java/com/google/gson/internal/Excluder.java

@@ -198,11 +198,7 @@ private boolean excludeClassChecks(Class<?> clazz) {
           return true;
       }
 
-      if (isAnonymousOrNonStaticLocal(clazz)) {
-          return true;
-      }
-
-      return false;
+    return isAnonymousOrNonStaticLocal(clazz);
   }
 
   public boolean excludeClass(Class<?> clazz, boolean serialize) {

gson/src/main/java/com/google/gson/internal/LinkedTreeMap.java

@@ -22,14 +22,7 @@
 import java.io.ObjectInputStream;
 import java.io.ObjectStreamException;
 import java.io.Serializable;
-import java.util.AbstractMap;
-import java.util.AbstractSet;
-import java.util.Comparator;
-import java.util.ConcurrentModificationException;
-import java.util.Iterator;
-import java.util.LinkedHashMap;
-import java.util.NoSuchElementException;
-import java.util.Set;
+import java.util.*;
 
 /**
  * A map of comparable keys to values. Unlike {@code TreeMap}, this class uses
@@ -227,7 +220,7 @@ Node<K, V> findByEntry(Entry<?, ?> entry) {
   }
 
   private boolean equal(Object a, Object b) {
-    return a == b || (a != null && a.equals(b));
+    return Objects.equals(a, b);
   }
 
   /**

gson/src/main/java/com/google/gson/internal/bind/JsonTreeReader.java

@@ -38,10 +38,10 @@
  */
 public final class JsonTreeReader extends JsonReader {
   private static final Reader UNREADABLE_READER = new Reader() {
-    @Override public int read(char[] buffer, int offset, int count) throws IOException {
+    @Override public int read(char[] buffer, int offset, int count) {
       throw new AssertionError();
     }
-    @Override public void close() throws IOException {
+    @Override public void close() {
       throw new AssertionError();
     }
   };

gson/src/main/java/com/google/gson/internal/bind/JsonTreeWriter.java

@@ -36,10 +36,10 @@ public final class JsonTreeWriter extends JsonWriter {
     @Override public void write(char[] buffer, int offset, int counter) {
       throw new AssertionError();
     }
-    @Override public void flush() throws IOException {
+    @Override public void flush() {
       throw new AssertionError();
     }
-    @Override public void close() throws IOException {
+    @Override public void close() {
       throw new AssertionError();
     }
   };

gson/src/main/java/com/google/gson/internal/bind/TreeTypeAdapter.java

@@ -176,7 +176,7 @@ private final class GsonContextImpl implements JsonSerializationContext, JsonDes
     }
     @SuppressWarnings("unchecked")
     @Override public <R> R deserialize(JsonElement json, Type typeOfT) throws JsonParseException {
-      return (R) gson.fromJson(json, typeOfT);
+      return gson.fromJson(json, typeOfT);
     }
   }
 }

gson/src/main/java/com/google/gson/stream/JsonReader.java

@@ -737,7 +737,7 @@ private int peekNumber() throws IOException {
     }
 
     // We've read a complete number. Decide if it's a PEEKED_LONG or a PEEKED_NUMBER.
-    if (last == NUMBER_CHAR_DIGIT && fitsInLong && (value != Long.MIN_VALUE || negative) && (value!=0 || false==negative)) {
+    if (last == NUMBER_CHAR_DIGIT && fitsInLong && (value != Long.MIN_VALUE || negative) && (value!=0 || !negative)) {
       peekedLong = negative ? value : -value;
       pos += i;
       return peeked = PEEKED_LONG;

metrics/src/main/java/com/google/gson/metrics/BagOfPrimitives.java

@@ -43,14 +43,12 @@ public int getIntValue() {
   }
 
   public String getExpectedJson() {
-    StringBuilder sb = new StringBuilder();
-    sb.append("{");
-    sb.append("\"longValue\":").append(longValue).append(",");
-    sb.append("\"intValue\":").append(intValue).append(",");
-    sb.append("\"booleanValue\":").append(booleanValue).append(",");
-    sb.append("\"stringValue\":\"").append(stringValue).append("\"");
-    sb.append("}");
-    return sb.toString();
+    return "{" +
+            "\"longValue\":" + longValue + "," +
+            "\"intValue\":" + intValue + "," +
+            "\"booleanValue\":" + booleanValue + "," +
+            "\"stringValue\":\"" + stringValue + "\"" +
+            "}";
   }
 
   @Override