/*
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* Copyright (C) 2011 Google Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package cn.emay.sdk.util.json.gson.internal.bind;
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import java.io.IOException;
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import java.io.Writer;
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import java.util.ArrayList;
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import java.util.List;
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import cn.emay.sdk.util.json.gson.JsonArray;
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import cn.emay.sdk.util.json.gson.JsonElement;
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import cn.emay.sdk.util.json.gson.JsonNull;
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import cn.emay.sdk.util.json.gson.JsonObject;
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import cn.emay.sdk.util.json.gson.JsonPrimitive;
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import cn.emay.sdk.util.json.gson.stream.JsonWriter;
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/**
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* This writer creates a JsonElement.
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*/
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public final class JsonTreeWriter extends JsonWriter {
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private static final Writer UNWRITABLE_WRITER = new Writer() {
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@Override
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public void write(char[] buffer, int offset, int counter) {
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throw new AssertionError();
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}
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@Override
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public void flush() throws IOException {
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throw new AssertionError();
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}
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@Override
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public void close() throws IOException {
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throw new AssertionError();
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}
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};
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/**
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* Added to the top of the stack when this writer is closed to cause following
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* ops to fail.
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*/
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private static final JsonPrimitive SENTINEL_CLOSED = new JsonPrimitive("closed");
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/**
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* The JsonElements and JsonArrays under modification, outermost to innermost.
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*/
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private final List<JsonElement> stack = new ArrayList<JsonElement>();
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/**
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* The name for the next JSON object value. If non-null, the top of the stack is
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* a JsonObject.
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*/
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private String pendingName;
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/** the JSON element constructed by this writer. */
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private JsonElement product = JsonNull.INSTANCE; // TODO: is this really what we want?;
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public JsonTreeWriter() {
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super(UNWRITABLE_WRITER);
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}
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/**
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* Returns the top level object produced by this writer.
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*/
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public JsonElement get() {
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if (!stack.isEmpty()) {
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throw new IllegalStateException("Expected one JSON element but was " + stack);
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}
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return product;
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}
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private JsonElement peek() {
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return stack.get(stack.size() - 1);
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}
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private void put(JsonElement value) {
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if (pendingName != null) {
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if (!value.isJsonNull() || getSerializeNulls()) {
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JsonObject object = (JsonObject) peek();
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object.add(pendingName, value);
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}
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pendingName = null;
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} else if (stack.isEmpty()) {
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product = value;
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} else {
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JsonElement element = peek();
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if (element instanceof JsonArray) {
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((JsonArray) element).add(value);
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} else {
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throw new IllegalStateException();
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}
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}
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}
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@Override
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public JsonWriter beginArray() throws IOException {
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JsonArray array = new JsonArray();
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put(array);
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stack.add(array);
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return this;
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}
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@Override
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public JsonWriter endArray() throws IOException {
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if (stack.isEmpty() || pendingName != null) {
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throw new IllegalStateException();
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}
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JsonElement element = peek();
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if (element instanceof JsonArray) {
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stack.remove(stack.size() - 1);
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return this;
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}
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throw new IllegalStateException();
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}
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@Override
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public JsonWriter beginObject() throws IOException {
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JsonObject object = new JsonObject();
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put(object);
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stack.add(object);
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return this;
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}
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@Override
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public JsonWriter endObject() throws IOException {
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if (stack.isEmpty() || pendingName != null) {
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throw new IllegalStateException();
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}
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JsonElement element = peek();
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if (element instanceof JsonObject) {
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stack.remove(stack.size() - 1);
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return this;
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}
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throw new IllegalStateException();
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}
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@Override
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public JsonWriter name(String name) throws IOException {
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if (stack.isEmpty() || pendingName != null) {
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throw new IllegalStateException();
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}
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JsonElement element = peek();
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if (element instanceof JsonObject) {
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pendingName = name;
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return this;
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}
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throw new IllegalStateException();
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}
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@Override
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public JsonWriter value(String value) throws IOException {
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if (value == null) {
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return nullValue();
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}
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put(new JsonPrimitive(value));
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return this;
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}
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@Override
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public JsonWriter nullValue() throws IOException {
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put(JsonNull.INSTANCE);
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return this;
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}
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@Override
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public JsonWriter value(boolean value) throws IOException {
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put(new JsonPrimitive(value));
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return this;
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}
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@Override
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public JsonWriter value(double value) throws IOException {
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if (!isLenient() && (Double.isNaN(value) || Double.isInfinite(value))) {
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throw new IllegalArgumentException("JSON forbids NaN and infinities: " + value);
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}
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put(new JsonPrimitive(value));
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return this;
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}
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@Override
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public JsonWriter value(long value) throws IOException {
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put(new JsonPrimitive(value));
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return this;
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}
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@Override
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public JsonWriter value(Number value) throws IOException {
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if (value == null) {
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return nullValue();
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}
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if (!isLenient()) {
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double d = value.doubleValue();
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if (Double.isNaN(d) || Double.isInfinite(d)) {
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throw new IllegalArgumentException("JSON forbids NaN and infinities: " + value);
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}
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}
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put(new JsonPrimitive(value));
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return this;
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}
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@Override
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public void flush() throws IOException {
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}
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@Override
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public void close() throws IOException {
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if (!stack.isEmpty()) {
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throw new IOException("Incomplete document");
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}
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stack.add(SENTINEL_CLOSED);
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}
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}
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