Package org.json

Class JSONObject


  • public class JSONObject
    extends java.lang.Object
    A JSONObject is an unordered collection of name/value pairs. Its external form is a string wrapped in curly braces with colons between the names and values, and commas between the values and names. The internal form is an object having get and opt methods for accessing the values by name, and put methods for adding or replacing values by name. The values can be any of these types: Boolean, JSONArray, JSONObject, Number, String, or the JSONObject.NULL object. A JSONObject constructor can be used to convert an external form JSON text into an internal form whose values can be retrieved with the get and opt methods, or to convert values into a JSON text using the put and toString methods. A get method returns a value if one can be found, and throws an exception if one cannot be found. An opt method returns a default value instead of throwing an exception, and so is useful for obtaining optional values.

    The generic get() and opt() methods return an object, which you can cast or query for type. There are also typed get and opt methods that do type checking and type coercion for you.

    The put methods adds values to an object. For example,

         myString = new JSONObject().put("JSON", "Hello, World!").toString();
    produces the string {"JSON": "Hello, World"}.

    The texts produced by the toString methods strictly conform to the JSON syntax rules. The constructors are more forgiving in the texts they will accept:

    • An extra , (comma) may appear just before the closing brace.
    • Strings may be quoted with ' (single quote).
    • Strings do not need to be quoted at all if they do not begin with a quote or single quote, and if they do not contain leading or trailing spaces, and if they do not contain any of these characters: { } [ ] / \ : , = ; # and if they do not look like numbers and if they are not the reserved words true, false, or null.
    • Keys can be followed by = or => as well as by :.
    • Values can be followed by ; (semicolon) as well as by , (comma).
    • Numbers may have the 0x- (hex) prefix.
    Since:
    Ptolemy II 10.0
    Version:
    $Id$, 2010-05-17
    Author:
    JSON.org
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.Object NULL
      It is sometimes more convenient and less ambiguous to have a NULL object than to use Java's null value.
    • Constructor Summary

      Constructors 
      Constructor Description
      JSONObject()
      Construct an empty JSONObject.
      JSONObject​(java.lang.Object bean)
      Construct a JSONObject from an Object using bean getters.
      JSONObject​(java.lang.Object object, java.lang.String[] names)
      Construct a JSONObject from an Object, using reflection to find the public members.
      JSONObject​(java.lang.String source)
      Construct a JSONObject from a source JSON text string.
      JSONObject​(java.util.Map map)
      Construct a JSONObject from a Map.
      JSONObject​(JSONObject jo, java.lang.String[] names)
      Construct a JSONObject from a subset of another JSONObject.
      JSONObject​(JSONTokener x)
      Construct a JSONObject from a JSONTokener.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      JSONObject accumulate​(java.lang.String key, java.lang.Object value)
      Accumulate values under a key.
      JSONObject append​(java.lang.String key, java.lang.Object value)
      Append values to the array under a key.
      static java.lang.String doubleToString​(double d)
      Produce a string from a double.
      java.lang.Object get​(java.lang.String key)
      Get the value object associated with a key.
      boolean getBoolean​(java.lang.String key)
      Get the boolean value associated with a key.
      double getDouble​(java.lang.String key)
      Get the double value associated with a key.
      int getInt​(java.lang.String key)
      Get the int value associated with a key.
      JSONArray getJSONArray​(java.lang.String key)
      Get the JSONArray value associated with a key.
      JSONObject getJSONObject​(java.lang.String key)
      Get the JSONObject value associated with a key.
      long getLong​(java.lang.String key)
      Get the long value associated with a key.
      static java.lang.String[] getNames​(java.lang.Object object)
      Get an array of field names from an Object.
      static java.lang.String[] getNames​(JSONObject jo)
      Get an array of field names from a JSONObject.
      java.lang.String getString​(java.lang.String key)
      Get the string associated with a key.
      boolean has​(java.lang.String key)
      Determine if the JSONObject contains a specific key.
      JSONObject increment​(java.lang.String key)
      Increment a property of a JSONObject.
      boolean isNull​(java.lang.String key)
      Determine if the value associated with the key is null or if there is no value.
      java.util.Iterator keys()
      Get an enumeration of the keys of the JSONObject.
      int length()
      Get the number of keys stored in the JSONObject.
      JSONArray names()
      Produce a JSONArray containing the names of the elements of this JSONObject.
      static java.lang.String numberToString​(java.lang.Number n)
      Produce a string from a Number.
      java.lang.Object opt​(java.lang.String key)
      Get an optional value associated with a key.
      boolean optBoolean​(java.lang.String key)
      Get an optional boolean associated with a key.
      boolean optBoolean​(java.lang.String key, boolean defaultValue)
      Get an optional boolean associated with a key.
      double optDouble​(java.lang.String key)
      Get an optional double associated with a key, or NaN if there is no such key or if its value is not a number.
      double optDouble​(java.lang.String key, double defaultValue)
      Get an optional double associated with a key, or the defaultValue if there is no such key or if its value is not a number.
      int optInt​(java.lang.String key)
      Get an optional int value associated with a key, or zero if there is no such key or if the value is not a number.
      int optInt​(java.lang.String key, int defaultValue)
      Get an optional int value associated with a key, or the default if there is no such key or if the value is not a number.
      JSONArray optJSONArray​(java.lang.String key)
      Get an optional JSONArray associated with a key.
      JSONObject optJSONObject​(java.lang.String key)
      Get an optional JSONObject associated with a key.
      long optLong​(java.lang.String key)
      Get an optional long value associated with a key, or zero if there is no such key or if the value is not a number.
      long optLong​(java.lang.String key, long defaultValue)
      Get an optional long value associated with a key, or the default if there is no such key or if the value is not a number.
      java.lang.String optString​(java.lang.String key)
      Get an optional string associated with a key.
      java.lang.String optString​(java.lang.String key, java.lang.String defaultValue)
      Get an optional string associated with a key.
      JSONObject put​(java.lang.String key, boolean value)
      Put a key/boolean pair in the JSONObject.
      JSONObject put​(java.lang.String key, double value)
      Put a key/double pair in the JSONObject.
      JSONObject put​(java.lang.String key, int value)
      Put a key/int pair in the JSONObject.
      JSONObject put​(java.lang.String key, long value)
      Put a key/long pair in the JSONObject.
      JSONObject put​(java.lang.String key, java.lang.Object value)
      Put a key/value pair in the JSONObject.
      JSONObject put​(java.lang.String key, java.util.Collection value)
      Put a key/value pair in the JSONObject, where the value will be a JSONArray which is produced from a Collection.
      JSONObject put​(java.lang.String key, java.util.Map value)
      Put a key/value pair in the JSONObject, where the value will be a JSONObject which is produced from a Map.
      JSONObject putOnce​(java.lang.String key, java.lang.Object value)
      Put a key/value pair in the JSONObject, but only if the key and the value are both non-null, and only if there is not already a member with that name.
      JSONObject putOpt​(java.lang.String key, java.lang.Object value)
      Put a key/value pair in the JSONObject, but only if the key and the value are both non-null.
      static java.lang.String quote​(java.lang.String string)
      Produce a string in double quotes with backslash sequences in all the right places.
      java.lang.Object remove​(java.lang.String key)
      Remove a name and its value, if present.
      java.util.Iterator sortedKeys()
      Get an enumeration of the keys of the JSONObject.
      static java.lang.Object stringToValue​(java.lang.String s)
      Try to convert a string into a number, boolean, or null.
      JSONArray toJSONArray​(JSONArray names)
      Produce a JSONArray containing the values of the members of this JSONObject.
      java.lang.String toString()
      Make a JSON text of this JSONObject.
      java.lang.String toString​(int indentFactor)
      Make a prettyprinted JSON text of this JSONObject.
      java.io.Writer write​(java.io.Writer writer)
      Write the contents of the JSONObject as JSON text to a writer.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Field Detail

      • NULL

        public static final java.lang.Object NULL
        It is sometimes more convenient and less ambiguous to have a NULL object than to use Java's null value. JSONObject.NULL.equals(null) returns true. JSONObject.NULL.toString() returns "null".
    • Constructor Detail

      • JSONObject

        public JSONObject()
        Construct an empty JSONObject.
      • JSONObject

        public JSONObject​(JSONObject jo,
                          java.lang.String[] names)
        Construct a JSONObject from a subset of another JSONObject. An array of strings is used to identify the keys that should be copied. Missing keys are ignored.
        Parameters:
        jo - A JSONObject.
        names - An array of strings.
      • JSONObject

        public JSONObject​(JSONTokener x)
                   throws JSONException
        Construct a JSONObject from a JSONTokener.
        Parameters:
        x - A JSONTokener object containing the source string.
        Throws:
        JSONException - If there is a syntax error in the source string or a duplicated key.
      • JSONObject

        public JSONObject​(java.util.Map map)
        Construct a JSONObject from a Map.
        Parameters:
        map - A map object that can be used to initialize the contents of the JSONObject.
      • JSONObject

        public JSONObject​(java.lang.Object bean)
        Construct a JSONObject from an Object using bean getters. It reflects on all of the public methods of the object. For each of the methods with no parameters and a name starting with "get" or "is" followed by an uppercase letter, the method is invoked, and a key and the value returned from the getter method are put into the new JSONObject. The key is formed by removing the "get" or "is" prefix. If the second remaining character is not upper case, then the first character is converted to lower case. For example, if an object has a method named "getName", and if the result of calling object.getName() is "Larry Fine", then the JSONObject will contain "name": "Larry Fine".
        Parameters:
        bean - An object that has getter methods that should be used to make a JSONObject.
      • JSONObject

        public JSONObject​(java.lang.Object object,
                          java.lang.String[] names)
        Construct a JSONObject from an Object, using reflection to find the public members. The resulting JSONObject's keys will be the strings from the names array, and the values will be the field values associated with those keys in the object. If a key is not found or not visible, then it will not be copied into the new JSONObject.
        Parameters:
        object - An object that has fields that should be used to make a JSONObject.
        names - An array of strings, the names of the fields to be obtained from the object.
      • JSONObject

        public JSONObject​(java.lang.String source)
                   throws JSONException
        Construct a JSONObject from a source JSON text string. This is the most commonly used JSONObject constructor.
        Parameters:
        source - A string beginning with { (left brace) and ending with } (right brace).
        Throws:
        JSONException - If there is a syntax error in the source string or a duplicated key.
    • Method Detail

      • accumulate

        public JSONObject accumulate​(java.lang.String key,
                                     java.lang.Object value)
                              throws JSONException
        Accumulate values under a key. It is similar to the put method except that if there is already an object stored under the key then a JSONArray is stored under the key to hold all of the accumulated values. If there is already a JSONArray, then the new value is appended to it. In contrast, the put method replaces the previous value.
        Parameters:
        key - A key string.
        value - An object to be accumulated under the key.
        Returns:
        this.
        Throws:
        JSONException - If the value is an invalid number or if the key is null.
      • append

        public JSONObject append​(java.lang.String key,
                                 java.lang.Object value)
                          throws JSONException
        Append values to the array under a key. If the key does not exist in the JSONObject, then the key is put in the JSONObject with its value being a JSONArray containing the value parameter. If the key was already associated with a JSONArray, then the value parameter is appended to it.
        Parameters:
        key - A key string.
        value - An object to be accumulated under the key.
        Returns:
        this.
        Throws:
        JSONException - If the key is null or if the current value associated with the key is not a JSONArray.
      • doubleToString

        public static java.lang.String doubleToString​(double d)
        Produce a string from a double. The string "null" will be returned if the number is not finite.
        Parameters:
        d - A double.
        Returns:
        A String.
      • get

        public java.lang.Object get​(java.lang.String key)
                             throws JSONException
        Get the value object associated with a key.
        Parameters:
        key - A key string.
        Returns:
        The object associated with the key.
        Throws:
        JSONException - if the key is not found.
      • getBoolean

        public boolean getBoolean​(java.lang.String key)
                           throws JSONException
        Get the boolean value associated with a key.
        Parameters:
        key - A key string.
        Returns:
        The truth.
        Throws:
        JSONException - if the value is not a Boolean or the String "true" or "false".
      • getDouble

        public double getDouble​(java.lang.String key)
                         throws JSONException
        Get the double value associated with a key.
        Parameters:
        key - A key string.
        Returns:
        The numeric value.
        Throws:
        JSONException - if the key is not found or if the value is not a Number object and cannot be converted to a number.
      • getInt

        public int getInt​(java.lang.String key)
                   throws JSONException
        Get the int value associated with a key.
        Parameters:
        key - A key string.
        Returns:
        The integer value.
        Throws:
        JSONException - if the key is not found or if the value cannot be converted to an integer.
      • getJSONArray

        public JSONArray getJSONArray​(java.lang.String key)
                               throws JSONException
        Get the JSONArray value associated with a key.
        Parameters:
        key - A key string.
        Returns:
        A JSONArray which is the value.
        Throws:
        JSONException - if the key is not found or if the value is not a JSONArray.
      • getJSONObject

        public JSONObject getJSONObject​(java.lang.String key)
                                 throws JSONException
        Get the JSONObject value associated with a key.
        Parameters:
        key - A key string.
        Returns:
        A JSONObject which is the value.
        Throws:
        JSONException - if the key is not found or if the value is not a JSONObject.
      • getLong

        public long getLong​(java.lang.String key)
                     throws JSONException
        Get the long value associated with a key.
        Parameters:
        key - A key string.
        Returns:
        The long value.
        Throws:
        JSONException - if the key is not found or if the value cannot be converted to a long.
      • getNames

        public static java.lang.String[] getNames​(JSONObject jo)
        Get an array of field names from a JSONObject.
        Returns:
        An array of field names, or null if there are no names.
      • getNames

        public static java.lang.String[] getNames​(java.lang.Object object)
        Get an array of field names from an Object.
        Returns:
        An array of field names, or null if there are no names.
      • getString

        public java.lang.String getString​(java.lang.String key)
                                   throws JSONException
        Get the string associated with a key.
        Parameters:
        key - A key string.
        Returns:
        A string which is the value.
        Throws:
        JSONException - if the key is not found.
      • has

        public boolean has​(java.lang.String key)
        Determine if the JSONObject contains a specific key.
        Parameters:
        key - A key string.
        Returns:
        true if the key exists in the JSONObject.
      • increment

        public JSONObject increment​(java.lang.String key)
                             throws JSONException
        Increment a property of a JSONObject. If there is no such property, create one with a value of 1. If there is such a property, and if it is an Integer, Long, Double, or Float, then add one to it.
        Parameters:
        key - A key string.
        Returns:
        this.
        Throws:
        JSONException - If there is already a property with this name that is not an Integer, Long, Double, or Float.
      • isNull

        public boolean isNull​(java.lang.String key)
        Determine if the value associated with the key is null or if there is no value.
        Parameters:
        key - A key string.
        Returns:
        true if there is no value associated with the key or if the value is the JSONObject.NULL object.
      • keys

        public java.util.Iterator keys()
        Get an enumeration of the keys of the JSONObject.
        Returns:
        An iterator of the keys.
      • length

        public int length()
        Get the number of keys stored in the JSONObject.
        Returns:
        The number of keys in the JSONObject.
      • names

        public JSONArray names()
        Produce a JSONArray containing the names of the elements of this JSONObject.
        Returns:
        A JSONArray containing the key strings, or null if the JSONObject is empty.
      • numberToString

        public static java.lang.String numberToString​(java.lang.Number n)
                                               throws JSONException
        Produce a string from a Number.
        Parameters:
        n - A Number
        Returns:
        A String.
        Throws:
        JSONException - If n is a non-finite number.
      • opt

        public java.lang.Object opt​(java.lang.String key)
        Get an optional value associated with a key.
        Parameters:
        key - A key string.
        Returns:
        An object which is the value, or null if there is no value.
      • optBoolean

        public boolean optBoolean​(java.lang.String key)
        Get an optional boolean associated with a key. It returns false if there is no such key, or if the value is not Boolean.TRUE or the String "true".
        Parameters:
        key - A key string.
        Returns:
        The truth.
      • optBoolean

        public boolean optBoolean​(java.lang.String key,
                                  boolean defaultValue)
        Get an optional boolean associated with a key. It returns the defaultValue if there is no such key, or if it is not a Boolean or the String "true" or "false" (case insensitive).
        Parameters:
        key - A key string.
        defaultValue - The default.
        Returns:
        The truth.
      • optDouble

        public double optDouble​(java.lang.String key)
        Get an optional double associated with a key, or NaN if there is no such key or if its value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.
        Parameters:
        key - A string which is the key.
        Returns:
        An object which is the value.
      • optDouble

        public double optDouble​(java.lang.String key,
                                double defaultValue)
        Get an optional double associated with a key, or the defaultValue if there is no such key or if its value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.
        Parameters:
        key - A key string.
        defaultValue - The default.
        Returns:
        An object which is the value.
      • optInt

        public int optInt​(java.lang.String key)
        Get an optional int value associated with a key, or zero if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.
        Parameters:
        key - A key string.
        Returns:
        An object which is the value.
      • optInt

        public int optInt​(java.lang.String key,
                          int defaultValue)
        Get an optional int value associated with a key, or the default if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.
        Parameters:
        key - A key string.
        defaultValue - The default.
        Returns:
        An object which is the value.
      • optJSONArray

        public JSONArray optJSONArray​(java.lang.String key)
        Get an optional JSONArray associated with a key. It returns null if there is no such key, or if its value is not a JSONArray.
        Parameters:
        key - A key string.
        Returns:
        A JSONArray which is the value.
      • optJSONObject

        public JSONObject optJSONObject​(java.lang.String key)
        Get an optional JSONObject associated with a key. It returns null if there is no such key, or if its value is not a JSONObject.
        Parameters:
        key - A key string.
        Returns:
        A JSONObject which is the value.
      • optLong

        public long optLong​(java.lang.String key)
        Get an optional long value associated with a key, or zero if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.
        Parameters:
        key - A key string.
        Returns:
        An object which is the value.
      • optLong

        public long optLong​(java.lang.String key,
                            long defaultValue)
        Get an optional long value associated with a key, or the default if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.
        Parameters:
        key - A key string.
        defaultValue - The default.
        Returns:
        An object which is the value.
      • optString

        public java.lang.String optString​(java.lang.String key)
        Get an optional string associated with a key. It returns an empty string if there is no such key. If the value is not a string and is not null, then it is converted to a string.
        Parameters:
        key - A key string.
        Returns:
        A string which is the value.
      • optString

        public java.lang.String optString​(java.lang.String key,
                                          java.lang.String defaultValue)
        Get an optional string associated with a key. It returns the defaultValue if there is no such key.
        Parameters:
        key - A key string.
        defaultValue - The default.
        Returns:
        A string which is the value.
      • put

        public JSONObject put​(java.lang.String key,
                              boolean value)
                       throws JSONException
        Put a key/boolean pair in the JSONObject.
        Parameters:
        key - A key string.
        value - A boolean which is the value.
        Returns:
        this.
        Throws:
        JSONException - If the key is null.
      • put

        public JSONObject put​(java.lang.String key,
                              java.util.Collection value)
                       throws JSONException
        Put a key/value pair in the JSONObject, where the value will be a JSONArray which is produced from a Collection.
        Parameters:
        key - A key string.
        value - A Collection value.
        Returns:
        this.
        Throws:
        JSONException
      • put

        public JSONObject put​(java.lang.String key,
                              double value)
                       throws JSONException
        Put a key/double pair in the JSONObject.
        Parameters:
        key - A key string.
        value - A double which is the value.
        Returns:
        this.
        Throws:
        JSONException - If the key is null or if the number is invalid.
      • put

        public JSONObject put​(java.lang.String key,
                              int value)
                       throws JSONException
        Put a key/int pair in the JSONObject.
        Parameters:
        key - A key string.
        value - An int which is the value.
        Returns:
        this.
        Throws:
        JSONException - If the key is null.
      • put

        public JSONObject put​(java.lang.String key,
                              long value)
                       throws JSONException
        Put a key/long pair in the JSONObject.
        Parameters:
        key - A key string.
        value - A long which is the value.
        Returns:
        this.
        Throws:
        JSONException - If the key is null.
      • put

        public JSONObject put​(java.lang.String key,
                              java.util.Map value)
                       throws JSONException
        Put a key/value pair in the JSONObject, where the value will be a JSONObject which is produced from a Map.
        Parameters:
        key - A key string.
        value - A Map value.
        Returns:
        this.
        Throws:
        JSONException
      • put

        public JSONObject put​(java.lang.String key,
                              java.lang.Object value)
                       throws JSONException
        Put a key/value pair in the JSONObject. If the value is null, then the key will be removed from the JSONObject if it is present.
        Parameters:
        key - A key string.
        value - An object which is the value. It should be of one of these types: Boolean, Double, Integer, JSONArray, JSONObject, Long, String, or the JSONObject.NULL object.
        Returns:
        this.
        Throws:
        JSONException - If the value is non-finite number or if the key is null.
      • putOnce

        public JSONObject putOnce​(java.lang.String key,
                                  java.lang.Object value)
                           throws JSONException
        Put a key/value pair in the JSONObject, but only if the key and the value are both non-null, and only if there is not already a member with that name.
        Parameters:
        key -
        value -
        Returns:
        his.
        Throws:
        JSONException - if the key is a duplicate
      • putOpt

        public JSONObject putOpt​(java.lang.String key,
                                 java.lang.Object value)
                          throws JSONException
        Put a key/value pair in the JSONObject, but only if the key and the value are both non-null.
        Parameters:
        key - A key string.
        value - An object which is the value. It should be of one of these types: Boolean, Double, Integer, JSONArray, JSONObject, Long, String, or the JSONObject.NULL object.
        Returns:
        this.
        Throws:
        JSONException - If the value is a non-finite number.
      • quote

        public static java.lang.String quote​(java.lang.String string)
        Produce a string in double quotes with backslash sequences in all the right places. A backslash will be inserted within </, allowing JSON text to be delivered in HTML. In JSON text, a string cannot contain a control character or an unescaped quote or backslash.
        Parameters:
        string - A String
        Returns:
        A String correctly formatted for insertion in a JSON text.
      • remove

        public java.lang.Object remove​(java.lang.String key)
        Remove a name and its value, if present.
        Parameters:
        key - The name to be removed.
        Returns:
        The value that was associated with the name, or null if there was no value.
      • sortedKeys

        public java.util.Iterator sortedKeys()
        Get an enumeration of the keys of the JSONObject. The keys will be sorted alphabetically.
        Returns:
        An iterator of the keys.
      • stringToValue

        public static java.lang.Object stringToValue​(java.lang.String s)
        Try to convert a string into a number, boolean, or null. If the string can't be converted, return the string.
        Parameters:
        s - A String.
        Returns:
        A simple JSON value.
      • toJSONArray

        public JSONArray toJSONArray​(JSONArray names)
                              throws JSONException
        Produce a JSONArray containing the values of the members of this JSONObject.
        Parameters:
        names - A JSONArray containing a list of key strings. This determines the sequence of the values in the result.
        Returns:
        A JSONArray of values.
        Throws:
        JSONException - If any of the values are non-finite numbers.
      • toString

        public java.lang.String toString()
        Make a JSON text of this JSONObject. For compactness, no whitespace is added. If this would not result in a syntactically correct JSON text, then null will be returned instead.

        Warning: This method assumes that the data structure is acyclical.

        Overrides:
        toString in class java.lang.Object
        Returns:
        a printable, displayable, portable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).
      • toString

        public java.lang.String toString​(int indentFactor)
                                  throws JSONException
        Make a prettyprinted JSON text of this JSONObject.

        Warning: This method assumes that the data structure is acyclical.

        Parameters:
        indentFactor - The number of spaces to add to each level of indentation.
        Returns:
        a printable, displayable, portable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).
        Throws:
        JSONException - If the object contains an invalid number.
      • write

        public java.io.Writer write​(java.io.Writer writer)
                             throws JSONException
        Write the contents of the JSONObject as JSON text to a writer. For compactness, no whitespace is added.

        Warning: This method assumes that the data structure is acyclical.

        Returns:
        The writer.
        Throws:
        JSONException