Support mixed streaming and databinding with new APIs.

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

@@ -17,6 +17,7 @@
 package com.google.gson;
 
 import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
 import java.io.IOException;
 import java.io.Reader;
 import java.io.StringReader;
@@ -110,6 +111,7 @@ public final class Gson {
 
   private final JsonFormatter formatter;
   private final boolean serializeNulls;
+  private final boolean htmlSafe;
 
   private final boolean generateNonExecutableJson;
 
@@ -151,7 +153,7 @@ public final class Gson {
     this(DEFAULT_EXCLUSION_STRATEGY, DEFAULT_EXCLUSION_STRATEGY, DEFAULT_NAMING_POLICY,
     new MappedObjectConstructor(DefaultTypeAdapters.getDefaultInstanceCreators()),
     DEFAULT_JSON_FORMATTER, false, DefaultTypeAdapters.getDefaultSerializers(),
-    DefaultTypeAdapters.getDefaultDeserializers(), DEFAULT_JSON_NON_EXECUTABLE);
+    DefaultTypeAdapters.getDefaultDeserializers(), DEFAULT_JSON_NON_EXECUTABLE, true);
   }
 
   Gson(ExclusionStrategy serializationStrategy, ExclusionStrategy deserializationStrategy,
@@ -159,7 +161,7 @@ public final class Gson {
       JsonFormatter formatter, boolean serializeNulls,
       ParameterizedTypeHandlerMap<JsonSerializer<?>> serializers,
       ParameterizedTypeHandlerMap<JsonDeserializer<?>> deserializers,
-      boolean generateNonExecutableGson) {
+      boolean generateNonExecutableGson, boolean htmlSafe) {
     this.serializationStrategy = serializationStrategy;
     this.deserializationStrategy = deserializationStrategy;
     this.fieldNamingPolicy = fieldNamingPolicy;
@@ -169,6 +171,7 @@ public final class Gson {
     this.serializers = serializers;
     this.deserializers = deserializers;
     this.generateNonExecutableJson = generateNonExecutableGson;
+    this.htmlSafe = htmlSafe;
   }
 
   private ObjectNavigatorFactory createDefaultObjectNavigatorFactory(ExclusionStrategy strategy) {
@@ -268,7 +271,7 @@ public final class Gson {
    */
   public String toJson(Object src, Type typeOfSrc) {
     StringWriter writer = new StringWriter();
-    toJson(src, typeOfSrc, writer);
+    toJson(toJsonTree(src, typeOfSrc), writer);
     return writer.toString();
   }
 
@@ -317,6 +320,14 @@ public final class Gson {
     toJson(jsonElement, writer);
   }
 
+  /**
+   * Writes the JSON representation of {@code src} of type {@code typeOfSrc} to
+   * {@code writer}.
+   */
+  public void toJson(Object src, Type typeOfSrc, JsonWriter writer) {
+    toJson(toJsonTree(src, typeOfSrc), writer);
+  }
+
   /**
    * Converts a tree of {@link JsonElement}s into its equivalent JSON representation.
    *
@@ -342,15 +353,30 @@ public final class Gson {
       if (generateNonExecutableJson) {
         writer.append(JSON_NON_EXECUTABLE_PREFIX);
       }
-      if (jsonElement == null && serializeNulls) {
-        writeOutNullString(writer);
-      }
-      formatter.format(jsonElement, writer, serializeNulls);
+      toJson(jsonElement, new JsonWriter(Streams.writerForAppendable(writer)));
     } catch (IOException e) {
       throw new RuntimeException(e);
     }
   }
 
+  /**
+   * Writes the JSON for {@code jsonElement} to {@code writer}.
+   */
+  public void toJson(JsonElement jsonElement, JsonWriter writer) {
+    boolean oldLenient = writer.isLenient();
+    writer.setLenient(true);
+    boolean oldHtmlSafe = writer.isHtmlSafe();
+    writer.setHtmlSafe(htmlSafe);
+    try {
+      Streams.write(jsonElement, serializeNulls, writer);
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    } finally {
+      writer.setLenient(oldLenient);
+      writer.setHtmlSafe(oldHtmlSafe);
+    }
+  }
+
   /**
    * This method deserializes the specified Json into an object of the specified class. It is not
    * suitable to use if the specified class is a generic type since it will not have the generic
@@ -417,7 +443,7 @@ public final class Gson {
    * @since 1.2
    */
   public <T> T fromJson(Reader json, Class<T> classOfT) throws JsonParseException {
-    T target = classOfT.cast(fromJson(json, (Type) classOfT));
+    T target = classOfT.cast(fromJson(new JsonReader(json), classOfT));
     return target;
   }
 
@@ -439,12 +465,24 @@ public final class Gson {
    * @throws JsonParseException if json is not a valid representation for an object of type typeOfT
    * @since 1.2
    */
-  @SuppressWarnings("unchecked")
   public <T> T fromJson(Reader json, Type typeOfT) throws JsonParseException {
-    JsonReader jsonReader = new JsonReader(json);
-    jsonReader.setLenient(true);
-    JsonElement root = Streams.parse(jsonReader);
-    return (T) fromJson(root, typeOfT);
+    return this.<T>fromJson(new JsonReader(json), typeOfT);
+  }
+
+  /**
+   * Reads the next JSON value from {@code reader} and convert it to an object
+   * of type {@code typeOfT}.
+   */
+  @SuppressWarnings("unchecked") // this method is unsafe and should be used very carefully
+  public <T> T fromJson(JsonReader reader, Type typeOfT) throws JsonParseException {
+    boolean oldLenient = reader.isLenient();
+    reader.setLenient(true);
+    try {
+      JsonElement root = Streams.parse(reader);
+      return (T) fromJson(root, typeOfT);
+    } finally {
+      reader.setLenient(oldLenient);
+    }
   }
 
   /**

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

@@ -546,7 +546,7 @@ public final class GsonBuilder {
         new JsonPrintFormatter(escapeHtmlChars) : new JsonCompactFormatter(escapeHtmlChars);
     Gson gson = new Gson(serializationExclusionStrategy, deserializationExclusionStrategy,
         fieldNamingPolicy, objConstructor, formatter, serializeNulls, customSerializers,
-        customDeserializers, generateNonExecutableJson);
+        customDeserializers, generateNonExecutableJson, escapeHtmlChars);
     return gson;
   }
 

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

@@ -50,10 +50,20 @@ public final class JsonParser {
    * @since 1.3
    */
   public JsonElement parse(Reader json) throws JsonParseException {
+    return parse(new JsonReader(json));
+  }
+
+  /**
+   * Returns the next value from the JSON stream as a parse tree.
+   *
+   * @throws JsonParseException if there is an IOException or if the specified
+   *     text is not valid JSON
+   */
+  public JsonElement parse(JsonReader json) throws JsonParseException {
+    boolean lenient = json.isLenient();
+    json.setLenient(true);
     try {
-      JsonReader jsonReader = new JsonReader(json);
-      jsonReader.setLenient(true);
-      return Streams.parse(jsonReader);
+      return Streams.parse(json);
     } catch (StackOverflowError e) {
       throw new JsonParseException("Failed parsing JSON source: " + json + " to Json", e);
     } catch (OutOfMemoryError e) {
@@ -64,6 +74,8 @@ public final class JsonParser {
       } else {
         throw e;
       }
+    } finally {
+      json.setLenient(lenient);
     }
-  }  
+  }
 }

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

@@ -142,6 +142,8 @@ public final class JsonWriter implements Closeable {
 
   private boolean lenient;
 
+  private boolean htmlSafe;
+
   /**
    * Creates a new instance that writes a JSON-encoded stream to {@code out}.
    * For best performance, ensure {@link Writer} is buffered; wrapping in
@@ -188,6 +190,32 @@ public final class JsonWriter implements Closeable {
     this.lenient = lenient;
   }
 
+  /**
+   * Returns true if this writer has relaxed syntax rules.
+   */
+  public boolean isLenient() {
+    return lenient;
+  }
+
+  /**
+   * Configure this writer to emit JSON that's safe for direct inclusion in HTML
+   * and XML documents. This escapes the HTML characters {@code <}, {@code >},
+   * {@code &} and {@code =} before writing them to the stream. Without this
+   * setting, your XML/HTML encoder should replace these characters with the
+   * corresponding escape sequences.
+   */
+  public void setHtmlSafe(boolean htmlSafe) {
+    this.htmlSafe = htmlSafe;
+  }
+
+  /**
+   * Returns true if this writer writes JSON that's safe for inclusion in HTML
+   * and XML documents.
+   */
+  public boolean isHtmlSafe() {
+    return htmlSafe;
+  }
+
   /**
    * Begins encoding a new array. Each call to this method must be paired with
    * a call to {@link #endArray}.
@@ -430,6 +458,18 @@ public final class JsonWriter implements Closeable {
         out.write("\\f");
         break;
 
+      case '<':
+      case '>':
+      case '&':
+      case '=':
+      case '\'':
+        if (htmlSafe) {
+          out.write(String.format("\\u%04x", (int) c));
+        } else {
+          out.write(c);
+        }
+        break;
+
       default:
         if (c <= 0x1F) {
           out.write(String.format("\\u%04x", (int) c));

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

@@ -42,7 +42,7 @@ public class FunctionWithInternalDependenciesTest extends TestCase {
     Gson gson = new Gson(exclusionStrategy, exclusionStrategy, Gson.DEFAULT_NAMING_POLICY,
         new MappedObjectConstructor(DefaultTypeAdapters.getDefaultInstanceCreators()),
         Gson.DEFAULT_JSON_FORMATTER, false, DefaultTypeAdapters.getDefaultSerializers(),
-        DefaultTypeAdapters.getDefaultDeserializers(), Gson.DEFAULT_JSON_NON_EXECUTABLE);
+        DefaultTypeAdapters.getDefaultDeserializers(), Gson.DEFAULT_JSON_NON_EXECUTABLE, true);
     assertEquals("{}", gson.toJson(new ClassWithNoFields() {
       // empty anonymous class
     }));

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

@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2010 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;
+
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import java.io.IOException;
+import java.io.StringReader;
+import java.io.StringWriter;
+import junit.framework.TestCase;
+
+public final class MixedStreamTest extends TestCase {
+
+  private static final Car BLUE_MUSTANG = new Car("mustang", 0x0000FF);
+  private static final Car BLACK_BMW = new Car("bmw", 0x000000);
+  private static final Car RED_MIATA = new Car("miata", 0xFF0000);
+  private static final String CARS_JSON = "[\n"
+      + "  {\n"
+      + "    \"name\": \"mustang\",\n"
+      + "    \"color\": 255\n"
+      + "  },\n"
+      + "  {\n"
+      + "    \"name\": \"bmw\",\n"
+      + "    \"color\": 0\n"
+      + "  },\n"
+      + "  {\n"
+      + "    \"name\": \"miata\",\n"
+      + "    \"color\": 16711680\n"
+      + "  }\n"
+      + "]";
+
+  public void testWriteMixedStreamed() throws IOException {
+    Gson gson = new Gson();
+    StringWriter stringWriter = new StringWriter();
+    JsonWriter jsonWriter = new JsonWriter(stringWriter);
+
+    jsonWriter.beginArray();
+    jsonWriter.setIndent("  ");
+    gson.toJson(BLUE_MUSTANG, Car.class, jsonWriter);
+    gson.toJson(BLACK_BMW, Car.class, jsonWriter);
+    gson.toJson(RED_MIATA, Car.class, jsonWriter);
+    jsonWriter.endArray();
+
+    assertEquals(CARS_JSON, stringWriter.toString());
+  }
+
+  public void testReadMixedStreamed() throws IOException {
+    Gson gson = new Gson();
+    StringReader stringReader = new StringReader(CARS_JSON);
+    JsonReader jsonReader = new JsonReader(stringReader);
+
+    jsonReader.beginArray();
+    assertEquals(BLUE_MUSTANG, gson.fromJson(jsonReader, Car.class));
+    assertEquals(BLACK_BMW, gson.fromJson(jsonReader, Car.class));
+    assertEquals(RED_MIATA, gson.fromJson(jsonReader, Car.class));
+    jsonReader.endArray();
+  }
+
+  static final class Car {
+    String name;
+    int color;
+
+    Car(String name, int color) {
+      this.name = name;
+      this.color = color;
+    }
+
+    Car() {} // for Gson
+
+    @Override public int hashCode() {
+      return name.hashCode() ^ color;
+    }
+
+    @Override public boolean equals(Object o) {
+      return o instanceof Car
+          && ((Car) o).name.equals(name)
+          && ((Car) o).color == color;
+    }
+  }
+}

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

@@ -54,7 +54,7 @@ public class EscapingTest extends TestCase {
     strings.add("&");
     strings.add("'");
     strings.add("\"");
-    assertEquals("[\"\\u003c\",\"\\u003e\",\"\\u003d\",\"\\u0026\",\"'\",\"\\\"\"]",
+    assertEquals("[\"\\u003c\",\"\\u003e\",\"\\u003d\",\"\\u0026\",\"\\u0027\",\"\\\"\"]",
         gson.toJson(strings));
   }
 

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

@@ -131,7 +131,7 @@ public class NullObjectAndFieldTest extends TestCase {
     gsonBuilder = new GsonBuilder();
     Gson gson = gsonBuilder.setPrettyPrinting().create();
     String result = gson.toJson(new ClassWithMembers());
-    assertEquals("{}\n", result);
+    assertEquals("{}", result);
 
     gson = gsonBuilder.serializeNulls().create();
     result = gson.toJson(new ClassWithMembers());
@@ -142,11 +142,11 @@ public class NullObjectAndFieldTest extends TestCase {
     gsonBuilder = new GsonBuilder();
     Gson gson = gsonBuilder.setPrettyPrinting().create();
     String result = gson.toJson(new String[] { "1", null, "3" });
-    assertEquals("[\"1\",null,\"3\"]\n", result);
+    assertEquals("[\"1\",null,\"3\"]", result);
 
     gson = gsonBuilder.serializeNulls().create();
     result = gson.toJson(new String[] { "1", null, "3" });
-    assertEquals("[\"1\",null,\"3\"]\n", result);
+    assertEquals("[\"1\",null,\"3\"]", result);
   }
 
   private static class ClassWithNullWrappedPrimitive {

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

@@ -59,34 +59,32 @@ public class PrettyPrintingTest extends TestCase {
     Type typeOfSrc = new TypeToken<List<BagOfPrimitives>>() {}.getType();
     String json = gson.toJson(listOfB, typeOfSrc);
     print(json);
-    assertPrintMargin(json);
   }
 
   public void testPrettyPrintArrayOfObjects() {
     ArrayOfObjects target = new ArrayOfObjects();
     String json = gson.toJson(target);
     print(json);
-    assertPrintMargin(json);
   }
 
   public void testPrettyPrintArrayOfPrimitives() {
     int[] ints = new int[] { 1, 2, 3, 4, 5 };
     String json = gson.toJson(ints);
-    assertEquals("[1,2,3,4,5]\n", json);
+    assertEquals("[1,2,3,4,5]", json);
   }
 
   public void testPrettyPrintArrayOfPrimitiveArrays() {
     int[][] ints = new int[][] { { 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 },
         { 9, 0 }, { 10 } };
     String json = gson.toJson(ints);
-    assertEquals("[[1,2],[3,4],[5,6],[7,8],[9,0],[10]]\n", json);
+    assertEquals("[[1,2],[3,4],[5,6],[7,8],[9,0],[10]]", json);
   }
 
   public void testPrettyPrintListOfPrimitiveArrays() {
     List<Integer[]> list = Arrays.asList(new Integer[][] { { 1, 2 }, { 3, 4 },
         { 5, 6 }, { 7, 8 }, { 9, 0 }, { 10 } });
     String json = gson.toJson(list);
-    assertEquals("[[1,2],[3,4],[5,6],[7,8],[9,0],[10]]\n", json);
+    assertEquals("[[1,2],[3,4],[5,6],[7,8],[9,0],[10]]", json);
   }
   
   public void testMap() {
@@ -94,7 +92,7 @@ public class PrettyPrintingTest extends TestCase {
     map.put("abc", 1);
     map.put("def", 5);
     String json = gson.toJson(map);
-    assertEquals("{\"abc\":1,\"def\":5}\n", json);
+    assertEquals("{\"abc\":1,\"def\":5}", json);
   }
 
   // In response to bug 153
@@ -114,7 +112,7 @@ public class PrettyPrintingTest extends TestCase {
   public void testMultipleArrays() {
     int[][][] ints = new int[][][] { { { 1 }, { 2 } } };
     String json = gson.toJson(ints);
-    assertEquals("[[[1],[2]]]\n", json);
+    assertEquals("[[[1],[2]]]", json);
   }
 
   private void print(String msg) {
@@ -122,16 +120,4 @@ public class PrettyPrintingTest extends TestCase {
       System.out.println(msg);
     }
   }
-
-  private void assertPrintMargin(String str) {
-    int position = 0;
-    char[] chars = str.toCharArray();
-    for (int i = 0; i < chars.length; ++i, ++position) {
-      char c = chars[i];
-      if (c == '\n') {
-        position = 0;
-      }
-      assertTrue(position <= PRINT_MARGIN - RIGHT_MARGIN + 1);
-    }
-  }
 }