JSONStringer.java

package com.jdroid.java.json;

/*
 * Copyright (c) 2006 JSON.org Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
 * Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The
 * above copyright notice and this permission notice shall be included in all copies or substantial portions of the
 * Software. The Software shall be used for Good, not Evil. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
 * KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

import java.io.StringWriter;

/**
 * JSONStringer provides a quick and convenient way of producing JSON text. The texts produced strictly conform to JSON
 * syntax rules. No whitespace is added, so the results are ready for transmission or storage. Each instance of
 * JSONStringer can produce one JSON text.
 * <p>
 * A JSONStringer instance provides a <code>value</code> method for appending values to the text, and a <code>key</code>
 * method for adding keys before values in objects. There are <code>array</code> and <code>endArray</code> methods that
 * make and bound array values, and <code>object</code> and <code>endObject</code> methods which make and bound object
 * values. All of these methods return the JSONWriter instance, permitting cascade style. For example,
 * 
 * <pre>
 * myString = new JSONStringer().object().key("JSON").value("Hello, World!").endObject().toString();
 * </pre>
 * 
 * which produces the string
 * 
 * <pre>
 * {"JSON":"Hello, World!"}
 * </pre>
 * <p>
 * The first method called must be <code>array</code> or <code>object</code>. There are no methods for adding commas or
 * colons. JSONStringer adds them for you. Objects and arrays can be nested up to 20 levels deep.
 * <p>
 * This can sometimes be easier than using a JSONObject to build a string.
 * 
 * @author JSON.org
 * @version 2008-09-18
 */
public class JSONStringer extends JSONWriter {
	
	/**
	 * Make a fresh JSONStringer. It can be used to build one JSON text.
	 */
	public JSONStringer() {
		super(new StringWriter());
	}
	
	/**
	 * Return the JSON text. This method is used to obtain the product of the JSONStringer instance. It will return
	 * <code>null</code> if there was a problem in the construction of the JSON text (such as the calls to
	 * <code>array</code> were not properly balanced with calls to <code>endArray</code>).
	 * 
	 * @return The JSON text.
	 */
	@Override
	public String toString() {
		return mode == 'd' ? writer.toString() : null;
	}
}