Package net.sf.json

Class JSONNull

  • All Implemented Interfaces:
    java.io.Serializable, JSON
    public final class JSONNull
extends java.lang.Object
implements JSON
    JSONNull is equivalent to the value that JavaScript calls null, whilst Java's null is equivalent to the value that JavaScript calls undefined.
    See Also:
    Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static JSONNull instance
      singleton instance

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private JSONNull()  

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean equals​(java.lang.Object object)
      A Null object is equal to the null value and to itself.
      static JSONNull getInstance()
      Returns the singleton instance of JSONNull
      int hashCode()  
      boolean isArray()
      Returns true if this object is a JSONArray, false otherwise.
      boolean isEmpty()
      Returns true if this object has no elements or keys.
      int size()
      Returns the number of properties in an object or the size of the array.
      java.lang.String toString()
      Get the "null" string value.
      java.lang.String toString​(int indentFactor)
      Make a prettyprinted JSON text.
      java.lang.String toString​(int indentFactor, int indent)
      Make a prettyprinted JSON text.
      java.io.Writer write​(java.io.Writer writer)
      Write the contents as JSON text to a writer.
      java.io.Writer writeCanonical​(java.io.Writer w)
      Writes the canonicalized form of this JSON object.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • instance

        private static JSONNull instance
        singleton instance

    • Constructor Detail

      • JSONNull

        private JSONNull()

    • Method Detail

      • getInstance

        public static JSONNull getInstance()
        Returns the singleton instance of JSONNull

      • equals

        public boolean equals​(java.lang.Object object)
        A Null object is equal to the null value and to itself.
        Overrides:
        equals in class java.lang.Object
        Parameters:
        object - An object to test for nullness.
        Returns:
        true if the object parameter is the JSONObject.NULL object or null.

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • isArray

        public boolean isArray()
        Description copied from interface: JSON
        Returns true if this object is a JSONArray, false otherwise.
        Specified by:
        isArray in interface JSON

      • isEmpty

        public boolean isEmpty()
        Description copied from interface: JSON
        Returns true if this object has no elements or keys.
        Specified by:
        isEmpty in interface JSON

      • size

        public int size()
        Description copied from interface: JSON
        Returns the number of properties in an object or the size of the array.
        Specified by:
        size in interface JSON
        Returns:
        the size of an json object or array

      • toString

        public java.lang.String toString()
        Get the "null" string value.
        Overrides:
        toString in class java.lang.Object
        Returns:
        The string "null".

      • toString

        public java.lang.String toString​(int indentFactor)
        Description copied from interface: JSON
        Make a prettyprinted JSON text.

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

        Specified by:
        toString in interface JSON
        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).

      • toString

        public java.lang.String toString​(int indentFactor,
                                 int indent)
        Description copied from interface: JSON
        Make a prettyprinted JSON text.

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

        Specified by:
        toString in interface JSON
        Parameters:
        indentFactor - The number of spaces to add to each level of indentation.
        indent - The indentation of the top level.
        Returns:
        a printable, displayable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).

      • write

        public java.io.Writer write​(java.io.Writer writer)
                     throws java.io.IOException
        Description copied from interface: JSON
        Write the contents as JSON text to a writer. For compactness, no whitespace is added.

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

        Specified by:
        write in interface JSON
        Returns:
        The writer.
        Throws:
        java.io.IOException

      • writeCanonical

        public java.io.Writer writeCanonical​(java.io.Writer w)
                              throws java.io.IOException
        Description copied from interface: JSON
        Writes the canonicalized form of this JSON object.
        Specified by:
        writeCanonical in interface JSON
        Throws:
        java.io.IOException