Module org.apache.derby.optionaltools
Package org.apache.derby.optional.api

Class SimpleJsonUtils

  • public abstract class SimpleJsonUtils
extends Object

    Utility methods for simple JSON support.

    • Constructor Detail

      • SimpleJsonUtils

        public SimpleJsonUtils()

    • Method Detail

      • toJSON

        public static org.json.simple.JSONArray toJSON​(ResultSet rs)
                                        throws SQLException

        Pack a ResultSet into a JSONArray. This method could be called client-side on any query result from any DBMS. Each row is converted into a JSONObject whose keys are the corresponding column names from the ResultSet. Closes the ResultSet once it has been drained. Datatypes map to JSON values as follows:

        • NULL - The JSON null literal.
        • SMALLINT, INT, BIGINT - JSON integer values.
        • DOUBLE, FLOAT, REAL, DECIMAL, NUMERIC - JSON floating point values.
        • CHAR, VARCHAR, LONG VARCHAR, CLOB - JSON string values.
        • BLOB, VARCHAR FOR BIT DATA, LONG VARCHAR FOR BIT DATA - The byte array is turned into a hex string (2 hex digits per byte) and the result is returned as a JSON string.
        • All other types - Converted to JSON string values via their toString() methods.
        Parameters:
        rs - A ResultSet to turn into a JSON array
        Returns:
        a json array
        Throws:
        SQLException - on error

      • readArray

        public static org.json.simple.JSONArray readArray​(Reader reader)
                                           throws SQLException
        Construct a JSONArray from a Reader.
        Parameters:
        reader - A Reader from which to de-serialize a json array
        Returns:
        a json array
        Throws:
        SQLException - on error

      • readArrayFromString

        public static org.json.simple.JSONArray readArrayFromString​(String document)
                                                     throws SQLException

        SQL FUNCTION to convert a JSON document string into a JSONArray. This function is registered by the simpleJson optional tool.

        Parameters:
        document - A json array as a string
        Returns:
        a json array
        Throws:
        SQLException - on error

      • readArrayFromStream

        public static org.json.simple.JSONArray readArrayFromStream​(InputStream inputStream,
                                                            String characterSetName)
                                                     throws SQLException
        Read a JSONArray from an InputStream. Close the stream after reading the JSONArray.
        Parameters:
        inputStream - A stream to read from
        characterSetName - The character set of the stream
        Returns:
        a json array
        Throws:
        SQLException - on error

      • readArrayFromFile

        public static org.json.simple.JSONArray readArrayFromFile​(String fileName,
                                                          String characterSetName)
                                                   throws SQLException
        SQL FUNCTION to read a JSONArray from a File. This function is registered by the simpleJson optional tool.
        Parameters:
        fileName - A file to read
        characterSetName - The character encoding of the file
        Returns:
        a json array
        Throws:
        SQLException - on error

      • readArrayFromURL

        public static org.json.simple.JSONArray readArrayFromURL​(String urlString,
                                                         String characterSetName)
                                                  throws SQLException
        SQL FUNCTION to read a JSONArray from an URL address. This function is registered by the simpleJson optional tool.
        Parameters:
        urlString - An url pointing to a json array
        characterSetName - The character encoding of the resource identified by the URL
        Returns:
        a json array
        Throws:
        SQLException - on error

      • arrayToClob

        public static Clob arrayToClob​(org.json.simple.JSONArray array)
        SQL FUNCTION to convert a JSONArray into a CLOB.
        Parameters:
        array - A json array
        Returns:
        a Clob containing the array as a string