<JDBC name="databaseAppender" tableName="APPLICATION_LOG">
            <ConnectionFactory class="com.yauhenikuntsevich.training.onlinestore.services.utils.ConnectionToDB"
                method="openConnectionToDB" />
            <Column name="EVENT_ID" literal="APPLICATION_LOG_SEQUENCE.NEXTVAL" />
            <Column name="EVENT_DATE" isEventTimestamp="true" />
            <Column name="LEVEL" pattern="%level" />
            <Column name="LOGGER" pattern="%logger" />
            <Column name="MESSAGE" pattern="%message" />
            <Column name="THROWABLE" pattern="%ex{full}" />
        </JDBC>

package com.yauhenikuntsevich.training.onlinestore.services.utils;

import java.sql.Connection;
import java.sql.DriverManager;

public class ConnectionToDB {
    private static final String URL = "jdbc:postgresql://localhost:5432/onlinestore";
    private static final String USER_NAME = "postgres";
    private static final String PASSWORD = "postgres1";

    public static Connection openConnectionToDB() {
        try {
            return DriverManager.getConnection(URL, USER_NAME, PASSWORD);
        } catch (Exception e) {
            System.out.println("Сonnection failed");
            e.printStackTrace();
        }
        return null;
    }
}

2016-12-08 21:20:10,229 ERROR Unable to write to database [jdbcManager{ description=databaseAppender, bufferSize=0, connectionSource=factory{ public static java.sql.Connection com.yauhenikuntsevich.training.onlinestore.services.utils.ConnectionToDB.openConnectionToDB() }, tableName=APPLICATION_LOG, columns=[ { name=EVENT_ID, layout=null, literal=APPLICATION_LOG_SEQUENCE.NEXTVAL, timestamp=false }, { name=EVENT_DATE, layout=null, literal=null, timestamp=true }, { name=LEVEL, layout=%level, literal=null, timestamp=false }, { name=LOGGER, layout=%logger, literal=null, timestamp=false }, { name=MESSAGE, layout=%message, literal=null, timestamp=false }, { name=THROWABLE, layout=%ex{full}, literal=null, timestamp=false } ] }] for appender [databaseAppender]. org.apache.logging.log4j.core.appender.AppenderLoggingException: Failed to insert record for log event in JDBC manager: Метод org.postgresql.jdbc.PgPreparedStatement.setNString(int, String) ещё не реализован

at org.apache.logging.log4j.core.appender.db.jdbc.JdbcDatabaseManager.writeInternal(JdbcDatabaseManager.java:125)
at org.apache.logging.log4j.core.appender.db.AbstractDatabaseManager.write(AbstractDatabaseManager.java:167)
at org.apache.logging.log4j.core.appender.db.AbstractDatabaseAppender.append(AbstractDatabaseAppender.java:105)
at org.apache.logging.log4j.core.config.AppenderControl.callAppender(AppenderControl.java:99)
at org.apache.logging.log4j.core.config.LoggerConfig.callAppenders(LoggerConfig.java:430)
at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:409)
at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:367)
at org.apache.logging.log4j.core.Logger.logMessage(Logger.java:112)
at org.apache.logging.slf4j.Log4jLogger.log(Log4jLogger.java:375)
at org.eclipse.jetty.util.log.JettyAwareLogger.log(JettyAwareLogger.java:620)
at org.eclipse.jetty.util.log.JettyAwareLogger.info(JettyAwareLogger.java:314)
at org.eclipse.jetty.util.log.Slf4jLog.info(Slf4jLog.java:74)
at org.eclipse.jetty.util.log.Log.initialized(Log.java:186)
at org.eclipse.jetty.util.log.Log.getLogger(Log.java:288)
at org.eclipse.jetty.util.log.Log.getLogger(Log.java:278)
at org.eclipse.jetty.util.component.AbstractLifeCycle.<clinit>(AbstractLifeCycle.java:35)
at com.yauhenikuntsevich.training.onlinestore.web.StartJetty.main(StartJetty.java:22)

Caused by: java.sql.SQLFeatureNotSupportedException: Метод org.postgresql.jdbc.PgPreparedStatement.setNString(int, String) ещё не реализован
at org.postgresql.Driver.notImplemented(Driver.java:646)
at org.postgresql.jdbc.PgPreparedStatement.setNString(PgPreparedStatement.java:1518)
at org.apache.logging.log4j.core.appender.db.jdbc.JdbcDatabaseManager.writeInternal(JdbcDatabaseManager.java:110)
... 16 more