| /* |
| * Copyright 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.gwt.dev.json; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| import java.io.Writer; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| /** |
| * JSON object. |
| */ |
| public class JsonObject implements JsonValue, Iterable<Pair<String, JsonValue>> { |
| private static class Iter implements Iterator<Pair<String, JsonValue>> { |
| private final Iterator<Map.Entry<String, JsonValue>> iter; |
| |
| Iter(Iterator<Map.Entry<String, JsonValue>> iter) { |
| this.iter = iter; |
| } |
| |
| @Override |
| public boolean hasNext() { |
| return iter.hasNext(); |
| } |
| |
| @Override |
| public Pair<String, JsonValue> next() { |
| final Map.Entry<String, JsonValue> entry = iter.next(); |
| return new Pair<String, JsonValue>(entry.getKey(), entry.getValue()); |
| } |
| |
| @Override |
| public void remove() { |
| iter.remove(); |
| } |
| } |
| |
| public static JsonObject create() { |
| return new JsonObject(); |
| } |
| |
| /** |
| * Creates a {@link JsonObject} from a valid JSON string. This routine expects |
| * the first non-whitespace character to be '{', then reads a single encoded |
| * object from the {@link Reader} and leaves the reader positioned after the |
| * last '}' character. |
| * |
| * @param reader {@link Reader} positioned to contain a JSON object encoded as |
| * a string. |
| * @return a valid {@link JsonObject} on success, throws exception on failure. |
| * @throws JsonException The input string is not in valid JSON format. |
| * @throws IOException An IO error was encountered before all of the string |
| * could be read. |
| */ |
| public static JsonObject parse(Reader reader) throws JsonException, |
| IOException { |
| return JsonObject.parse(new Tokenizer(reader)); |
| } |
| |
| static JsonObject parse(Tokenizer tokenizer) throws IOException, |
| JsonException { |
| final JsonObject object = new JsonObject(); |
| int c = tokenizer.nextNonWhitespace(); |
| if (c != '{') { |
| throw new JsonException("Payload does not begin with '{'. Got " + c + "(" |
| + Character.valueOf((char) c) + ")"); |
| } |
| |
| while (true) { |
| c = tokenizer.nextNonWhitespace(); |
| switch (c) { |
| case '}': |
| // We're done. |
| return object; |
| case '"': |
| tokenizer.back(c); |
| // Ready to start a key. |
| final String key = tokenizer.nextString(); |
| if (tokenizer.nextNonWhitespace() != ':') { |
| throw new JsonException("Invalid object: expecting \":\""); |
| } |
| // TODO(knorton): Make sure this key is not already set. |
| object.put(key, tokenizer.nextValue()); |
| switch (tokenizer.nextNonWhitespace()) { |
| case ',': |
| break; |
| case '}': |
| return object; |
| default: |
| throw new JsonException("Invalid object: expecting } or ,"); |
| } |
| break; |
| case ',': |
| break; |
| default: |
| throw new JsonException("Invalid object: "); |
| } |
| } |
| } |
| |
| private final Map<String, JsonValue> properties = new HashMap<String, JsonValue>(); |
| |
| public JsonObject() { |
| } |
| |
| @Override |
| public JsonArray asArray() { |
| return null; |
| } |
| |
| @Override |
| public JsonBoolean asBoolean() { |
| return null; |
| } |
| |
| @Override |
| public JsonNumber asNumber() { |
| return null; |
| } |
| |
| @Override |
| public JsonObject asObject() { |
| return this; |
| } |
| |
| @Override |
| public JsonString asString() { |
| return null; |
| } |
| |
| @Override |
| public JsonObject copyDeeply() { |
| final JsonObject copy = new JsonObject(); |
| for (Map.Entry<String, JsonValue> entry : properties.entrySet()) { |
| final JsonValue value = entry.getValue(); |
| copy.properties.put(entry.getKey(), value == null ? null |
| : value.copyDeeply()); |
| } |
| return copy; |
| } |
| |
| public JsonValue get(String key) { |
| final JsonValue value = properties.get(key); |
| return (value == null) ? JsonValue.NULL : value; |
| } |
| |
| @Override |
| public boolean isArray() { |
| return false; |
| } |
| |
| @Override |
| public boolean isBoolean() { |
| return false; |
| } |
| |
| public boolean isEmpty() { |
| return properties.isEmpty(); |
| } |
| |
| @Override |
| public boolean isNumber() { |
| return false; |
| } |
| |
| @Override |
| public boolean isObject() { |
| return true; |
| } |
| |
| @Override |
| public boolean isString() { |
| return false; |
| } |
| |
| @Override |
| public Iterator<Pair<String, JsonValue>> iterator() { |
| return new Iter(properties.entrySet().iterator()); |
| } |
| |
| public void put(String key, boolean val) { |
| put(key, JsonBoolean.create(val)); |
| } |
| |
| public void put(String key, double val) { |
| put(key, JsonNumber.create(val)); |
| } |
| |
| public void put(String key, JsonValue val) { |
| properties.put(key, val); |
| } |
| |
| public void put(String key, long val) { |
| put(key, JsonNumber.create(val)); |
| } |
| |
| public void put(String key, String val) { |
| put(key, JsonString.create(val)); |
| } |
| |
| @Override |
| public void write(Writer writer) throws IOException { |
| boolean first = true; |
| writer.write('{'); |
| for (Map.Entry<String, JsonValue> e : properties.entrySet()) { |
| if (!first) { |
| writer.append(','); |
| } else { |
| first = false; |
| } |
| JsonString.write(e.getKey(), writer); |
| writer.append(':'); |
| e.getValue().write(writer); |
| } |
| writer.write('}'); |
| } |
| } |