Package com.github.openjson

Class JSONStringer

  • public class JSONStringer
extends Object
    Implements JSONObject.toString() and JSONArray.toString(). Most application developers should use those methods directly and disregard this API. For example:
     JSONObject object = ...
 String json = object.toString();

    Stringers only encode well-formed JSON strings. In particular:

    • The stringer must have exactly one top-level array or object.
    • Lexical scopes must be balanced: every call to array() must have a matching call to endArray() and every call to object() must have a matching call to endObject().
    • Arrays may not contain keys (property names).
    • Objects must alternate keys (property names) and values.
    • Values are inserted with either literal value calls, or by nesting arrays or objects.
    Calls that would result in a malformed JSON string will fail with a JSONException.

    This class provides no facility for pretty-printing (ie. indenting) output. To encode indented output, use JSONObject.toString(int) or JSONArray.toString(int).

    Some implementations of the API support at most 20 levels of nesting. Attempts to create more than 20 levels of nesting may fail with a JSONException.

    Each stringer may be used to encode a single top level value. Instances of this class are not thread safe. Although this class is nonfinal, it was not designed for inheritance and should not be subclassed. In particular, self-use by overrideable methods is not specified. See Effective Java Item 17, "Design and Document or inheritance or else prohibit it" for further information.

    • Field Detail

      • out

        protected final StringBuilder out
        The output data, containing at most one top-level array or object.

    • Constructor Detail

      • JSONStringer

        public JSONStringer()

      • JSONStringer

        public JSONStringer​(int indentSpaces)

    • Method Detail

      • array

        public JSONStringer array()
                   throws JSONException
        Begins encoding a new array. Each call to this method must be paired with a call to endArray().
        Returns:
        this stringer.
        Throws:
        JSONException - On internal errors. Shouldn't happen.

      • value

        public JSONStringer value​(boolean value)
                   throws JSONException
        Encodes value to this stringer.
        Parameters:
        value - The value to encode.
        Returns:
        this stringer.
        Throws:
        JSONException - On internal errors. Shouldn't happen.

      • value

        public JSONStringer value​(long value)
                   throws JSONException
        Encodes value to this stringer.
        Parameters:
        value - The value to encode.
        Returns:
        this stringer.
        Throws:
        JSONException - If we have an internal error. Shouldn't happen.

      • entry

        public JSONStringer entry​(Map.Entry<String,​Object> entry)
        Encodes key/value pair to this stringer.
        Parameters:
        entry - The entry to encode.
        Returns:
        this stringer.
        Throws:
        JSONException - If we have an internal error. Shouldn't happen.

      • createKey

        protected JSONStringer createKey​(String name)
        Creates String representation of the key (property name) to this stringer Override this method to provide your own representation of the name.
        Parameters:
        name - the name of the forthcoming value.
        Returns:
        this stringer.

      • key

        public JSONStringer key​(String name)
                 throws JSONException
        Encodes the key (property name) to this stringer.
        Parameters:
        name - the name of the forthcoming value. May not be null.
        Returns:
        this stringer.
        Throws:
        JSONException - on internal errors, shouldn't happen.

      • toString

        public String toString()
        Returns the encoded JSON string.

        If invoked with unterminated arrays or unclosed objects, this method's return value is undefined.

        Warning: although it contradicts the general contract of Object.toString(), this method returns null if the stringer contains no data.

        Overrides:
        toString in class Object