Stream to a DOM

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

@@ -51,8 +51,11 @@ public final class JsonElementWriter extends JsonWriter {
   }
 
   public JsonElement get() {
+    if (stack.isEmpty()) {
+      return JsonNull.INSTANCE; // TODO: is this really what we want?
+    }
     if (stack.size() != 1) {
-      throw new IllegalStateException();
+      throw new IllegalStateException("Expected one JSON element but was " + stack);
     }
     return stack.get(0);
   }
@@ -129,6 +132,9 @@ public final class JsonElementWriter extends JsonWriter {
   }
 
   @Override public JsonWriter value(String value) throws IOException {
+    if (value == null) {
+      return nullValue();
+    }
     put(new JsonPrimitive(value));
     return this;
   }
@@ -154,6 +160,9 @@ public final class JsonElementWriter extends JsonWriter {
   }
 
   @Override public JsonWriter value(Number value) throws IOException {
+    if (value == null) {
+      return nullValue();
+    }
     put(new JsonPrimitive(value));
     return this;
   }

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

@@ -18,11 +18,9 @@ package com.google.gson.internal.bind;
 
 import com.google.gson.JsonElement;
 import com.google.gson.JsonIOException;
-import com.google.gson.internal.Streams;
 import com.google.gson.reflect.TypeToken;
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonWriter;
-
 import java.io.IOException;
 import java.io.Reader;
 import java.io.StringReader;
@@ -56,13 +54,10 @@ public abstract class TypeAdapter<T> {
 
   public JsonElement toJsonElement(T src) {
     try {
-      StringWriter stringWriter = new StringWriter();
-      JsonWriter jsonWriter = new JsonWriter(stringWriter);
+      JsonElementWriter jsonWriter = new JsonElementWriter();
       jsonWriter.setLenient(true);
       write(jsonWriter, src);
-      JsonReader reader = new JsonReader(new StringReader(stringWriter.toString()));
-      reader.setLenient(true);
-      return Streams.parse(reader);
+      return jsonWriter.get();
     } catch (IOException e) {
       throw new JsonIOException(e);
     }

gson/src/test/java/com/google/gson/internal/bind/JsonElementWriterTest.java

@@ -23,6 +23,7 @@ public final class JsonElementWriterTest extends TestCase {
 
   // TODO: more tests
   // TODO: close support
+  // TODO: figure out what should be returned by an empty writer
 
   public void testArray() throws IOException {
     JsonElementWriter writer = new JsonElementWriter();