How to store json value using JDBC appender-CodePudding

I would like to store a JSON field through JDBC appender using Log4j 2. This is my configuration and I am not able to store into PostgreSQL JSON type column:

<Configuration status="WARN">
    <Appenders>
        <JDBC name="databaseAppender" tableName="logs.logs">
            <ConnectionFactory
                
                method="getDatabaseConnection" />
            <Column name="id" literal="nextval('logs.logs_id_seq')" />
            <Column name="date" isEventTimestamp="true" />
            <Column name="level" pattern="%level" isUnicode="false" />
            ...
            <Column name="data" ??? />
        </JDBC>
    </Appenders>
    <Loggers>
        <Root level="info">
            <AppenderRef ref="databaseAppender" />
        </Root>
    </Loggers>
</Configuration>

This is my meta table definition in PostgreSQL:

CREATE TABLE logs (
    id int4 NOT NULL,
    message varchar NULL,
    fullinfo varchar NULL,
    "level" varchar NULL,
    ...
    "data" json NULL,
    CONSTRAINT id_logs PRIMARY KEY (id)
);

My Java code fills a MapMessage and then calls info method of ExtendedLogger:

final LoggerContext ctx = (LoggerContext) LogManager.getContext(false);
ExtendedLogger log = ctx.getLogger(clazz.getName());
MapMessage map = new MapMessage();
... // put all other data into MapMessage
map.put("data", new JSONObject()) // or JsonNode, String or whatever else
log.info(map);

How to store "data" field into a PostgreSQL JSON column using ConnectionFactory of JDBC Appender? Is it possible using Log4j 2?

CodePudding user response：

You could use the "columnMapping" tag instead of "column" which supports the "parameter" attribute where you can insert an expression using '?' as a marker and adding a cast to json. In your case:

<ColumnMapping name="data" pattern="%K{data}" parameter="?::json" />