Move gson to its own folder

[unical.git] / gson / com / google / gson / internal / bind / JsonTreeWriter.java

diff --git a/gson/com/google/gson/internal/bind/JsonTreeWriter.java b/gson/com/google/gson/internal/bind/JsonTreeWriter.java
new file mode 100644 (file)
index 0000000..5f9f039
--- /dev/null
+++ b/gson/com/google/gson/internal/bind/JsonTreeWriter.java
@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) 2011 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.internal.bind;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonNull;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonPrimitive;
+import com.google.gson.stream.JsonWriter;
+import java.io.IOException;
+import java.io.Writer;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * This writer creates a JsonElement.
+ */
+public final class JsonTreeWriter extends JsonWriter {
+  private static final Writer UNWRITABLE_WRITER = new Writer() {
+    @Override public void write(char[] buffer, int offset, int counter) {
+      throw new AssertionError();
+    }
+    @Override public void flush() throws IOException {
+      throw new AssertionError();
+    }
+    @Override public void close() throws IOException {
+      throw new AssertionError();
+    }
+  };
+  /** Added to the top of the stack when this writer is closed to cause following ops to fail. */
+  private static final JsonPrimitive SENTINEL_CLOSED = new JsonPrimitive("closed");
+
+  /** The JsonElements and JsonArrays under modification, outermost to innermost. */
+  private final List<JsonElement> stack = new ArrayList<JsonElement>();
+
+  /** The name for the next JSON object value. If non-null, the top of the stack is a JsonObject. */
+  private String pendingName;
+
+  /** the JSON element constructed by this writer. */
+  private JsonElement product = JsonNull.INSTANCE; // TODO: is this really what we want?;
+
+  public JsonTreeWriter() {
+    super(UNWRITABLE_WRITER);
+  }
+
+  /**
+   * Returns the top level object produced by this writer.
+   */
+  public JsonElement get() {
+    if (!stack.isEmpty()) {
+      throw new IllegalStateException("Expected one JSON element but was " + stack);
+    }
+    return product;
+  }
+
+  private JsonElement peek() {
+    return stack.get(stack.size() - 1);
+  }
+
+  private void put(JsonElement value) {
+    if (pendingName != null) {
+      if (!value.isJsonNull() || getSerializeNulls()) {
+        JsonObject object = (JsonObject) peek();
+        object.add(pendingName, value);
+      }
+      pendingName = null;
+    } else if (stack.isEmpty()) {
+      product = value;
+    } else {
+      JsonElement element = peek();
+      if (element instanceof JsonArray) {
+        ((JsonArray) element).add(value);
+      } else {
+        throw new IllegalStateException();
+      }
+    }
+  }
+
+  @Override public JsonWriter beginArray() throws IOException {
+    JsonArray array = new JsonArray();
+    put(array);
+    stack.add(array);
+    return this;
+  }
+
+  @Override public JsonWriter endArray() throws IOException {
+    if (stack.isEmpty() || pendingName != null) {
+      throw new IllegalStateException();
+    }
+    JsonElement element = peek();
+    if (element instanceof JsonArray) {
+      stack.remove(stack.size() - 1);
+      return this;
+    }
+    throw new IllegalStateException();
+  }
+
+  @Override public JsonWriter beginObject() throws IOException {
+    JsonObject object = new JsonObject();
+    put(object);
+    stack.add(object);
+    return this;
+  }
+
+  @Override public JsonWriter endObject() throws IOException {
+    if (stack.isEmpty() || pendingName != null) {
+      throw new IllegalStateException();
+    }
+    JsonElement element = peek();
+    if (element instanceof JsonObject) {
+      stack.remove(stack.size() - 1);
+      return this;
+    }
+    throw new IllegalStateException();
+  }
+
+  @Override public JsonWriter name(String name) throws IOException {
+    if (stack.isEmpty() || pendingName != null) {
+      throw new IllegalStateException();
+    }
+    JsonElement element = peek();
+    if (element instanceof JsonObject) {
+      pendingName = name;
+      return this;
+    }
+    throw new IllegalStateException();
+  }
+
+  @Override public JsonWriter value(String value) throws IOException {
+    if (value == null) {
+      return nullValue();
+    }
+    put(new JsonPrimitive(value));
+    return this;
+  }
+
+  @Override public JsonWriter nullValue() throws IOException {
+    put(JsonNull.INSTANCE);
+    return this;
+  }
+
+  @Override public JsonWriter value(boolean value) throws IOException {
+    put(new JsonPrimitive(value));
+    return this;
+  }
+
+  @Override public JsonWriter value(double value) throws IOException {
+    if (!isLenient() && (Double.isNaN(value) || Double.isInfinite(value))) {
+      throw new IllegalArgumentException("JSON forbids NaN and infinities: " + value);
+    }
+    put(new JsonPrimitive(value));
+    return this;
+  }
+
+  @Override public JsonWriter value(long value) throws IOException {
+    put(new JsonPrimitive(value));
+    return this;
+  }
+
+  @Override public JsonWriter value(Number value) throws IOException {
+    if (value == null) {
+      return nullValue();
+    }
+
+    if (!isLenient()) {
+      double d = value.doubleValue();
+      if (Double.isNaN(d) || Double.isInfinite(d)) {
+        throw new IllegalArgumentException("JSON forbids NaN and infinities: " + value);
+      }
+    }
+
+    put(new JsonPrimitive(value));
+    return this;
+  }
+
+  @Override public void flush() throws IOException {
+  }
+
+  @Override public void close() throws IOException {
+    if (!stack.isEmpty()) {
+      throw new IOException("Incomplete document");
+    }
+    stack.add(SENTINEL_CLOSED);
+  }
+}