content: package org.json;
  
  /*
  Public Domain.
  */
  
  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 200 levels deep.
   * <p>
   * This can sometimes be easier than using a JSONObject to build a string.
   * @author JSON.org
   * @version 2015-12-09
   */
  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 this.mode == 'd' ? this.writer.toString() : null;
      }
  }
  