Package org.grails.web.json

Class JSONObject

  • All Implemented Interfaces:
    groovy.lang.Writable, java.util.Map, JSONElement
    public class JSONObject
extends java.lang.Object
implements JSONElement, java.util.Map
    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, or String. 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 coersion 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 sysntax 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 =$gt; as well as by :.
    • Values can be followed by ; (semicolon) as well as by , (comma).
    • Numbers may have the 0- (octal) or 0x- (hex) prefix.
    • Comments written in the slashshlash, slashstar, and hash conventions will be ignored.

    • Nested Class Summary

      • Nested classes/interfaces inherited from interface java.util.Map

        java.util.Map.Entry<K extends java.lang.Object,​V extends java.lang.Object>

    • Constructor Summary

      Constructors 
      Constructor Description
      JSONObject()
      Construct an empty JSONObject.
      JSONObject​(java.lang.String string)
      Construct a JSONObject from a string.
      JSONObject​(java.util.Map map)
      Construct a JSONObject from a Map.
      JSONObject​(JSONObject jo, java.lang.String[] sa)
      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.
      void clear()  
      static java.lang.String collectionToString​(java.util.Collection c)  
      boolean containsKey​(java.lang.Object o)  
      boolean containsValue​(java.lang.Object o)  
      static java.lang.String dateToString​(java.util.Date d)  
      protected static void encodeToWriter​(java.lang.CharSequence str, java.io.Writer writer)  
      java.util.Set entrySet()  
      boolean equals​(java.lang.Object o)  
      java.lang.Object get​(java.lang.Object o)  
      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.
      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.
      int hashCode()  
      boolean isEmpty()  
      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.
      java.util.Set keySet()  
      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.
      java.lang.Object put​(java.lang.Object o, java.lang.Object o1)  
      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.
      void putAll​(java.util.Map map)  
      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.Object o)  
      java.lang.Object remove​(java.lang.String key)
      Remove a name and its value, if present.
      int size()  
      JSONArray toJSONArray​(JSONArray names)
      Produce a JSONArray containing the values of the members of this JSONObject.
      java.lang.String toString()
      Make an JSON text of this JSONObject.
      java.lang.String toString​(int indentFactor)
      Make a prettyprinted JSON text of this JSONObject.
      java.util.Collection values()  
      java.io.Writer write​(java.io.Writer writer)
      Write the contents of the JSONObject as JSON text to a writer.
      java.io.Writer writeTo​(java.io.Writer out)  

      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait

      • Methods inherited from interface java.util.Map

        compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

    • Constructor Detail

      • JSONObject

        public JSONObject()
        Construct an empty JSONObject.

      • JSONObject

        public JSONObject​(JSONObject jo,
                  java.lang.String[] sa)
           throws JSONException
        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.
        sa - An array of strings.
        Throws:
        JSONException - If a value is a non-finite number.

      • 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.

      • 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.String string)
           throws JSONException
        Construct a JSONObject from a string. This is the most commonly used JSONObject constructor.
        Parameters:
        string - A string beginning with { (left brace) and ending with } (right brace).
        Throws:
        JSONException - If there is a syntax error in the source string.

    • 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.

      • 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. If the number value is too large for an int, it will be clipped.
        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. If the number value is too long for a long, it will be clipped.
        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.

      • 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.

      • 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.

      • collectionToString

        public static java.lang.String collectionToString​(java.util.Collection c)

      • 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 coverted 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,
                      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.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.

      • 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.

      • 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 an 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.

      • encodeToWriter

        protected static void encodeToWriter​(java.lang.CharSequence str,
                                     java.io.Writer writer)
                              throws java.io.IOException
        Throws:
        java.io.IOException

      • 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

      • size

        public int size()
        Specified by:
        size in interface java.util.Map

      • isEmpty

        public boolean isEmpty()
        Specified by:
        isEmpty in interface java.util.Map

      • containsKey

        public boolean containsKey​(java.lang.Object o)
        Specified by:
        containsKey in interface java.util.Map

      • containsValue

        public boolean containsValue​(java.lang.Object o)
        Specified by:
        containsValue in interface java.util.Map

      • get

        public java.lang.Object get​(java.lang.Object o)
        Specified by:
        get in interface java.util.Map

      • put

        public java.lang.Object put​(java.lang.Object o,
                            java.lang.Object o1)
        Specified by:
        put in interface java.util.Map

      • remove

        public java.lang.Object remove​(java.lang.Object o)
        Specified by:
        remove in interface java.util.Map

      • putAll

        public void putAll​(java.util.Map map)
        Specified by:
        putAll in interface java.util.Map

      • clear

        public void clear()
        Specified by:
        clear in interface java.util.Map

      • keySet

        public java.util.Set keySet()
        Specified by:
        keySet in interface java.util.Map

      • values

        public java.util.Collection values()
        Specified by:
        values in interface java.util.Map

      • entrySet

        public java.util.Set entrySet()
        Specified by:
        entrySet in interface java.util.Map

      • equals

        public boolean equals​(java.lang.Object o)
        Specified by:
        equals in interface java.util.Map
        Overrides:
        equals in class java.lang.Object

      • hashCode

        public int hashCode()
        Specified by:
        hashCode in interface java.util.Map
        Overrides:
        hashCode in class java.lang.Object

      • writeTo

        public java.io.Writer writeTo​(java.io.Writer out)
                       throws java.io.IOException
        Specified by:
        writeTo in interface groovy.lang.Writable
        Throws:
        java.io.IOException