public class CustomTracingStatementInterceptor implements StatementInterceptorV2 {

    private final ThreadLocal<Span> currentSpanInScope = new ThreadLocal<>();

    @Override
    @Nullable
    public ResultSetInternalMethods preProcess(String sql, Statement interceptedStatement,
                                               Connection connection) {
        final Tracer tracer = Tracing.currentTracer();
        if (tracer == null) {
            return null;
        }
        final Span span = tracer.nextSpan();
        if (span.isNoop()) {
            return null;
        }

        currentSpanInScope.set(span);
        // When running a prepared statement, sql will be null and we must fetch the sql from the statement itself
        if (interceptedStatement instanceof PreparedStatement) {
            sql = ((PreparedStatement) interceptedStatement).getPreparedSql();
        }
        final int spaceIndex = sql.indexOf(' '); // Allow span names of single-word statements like COMMIT
        span.kind(Span.Kind.CLIENT).name(spaceIndex == -1 ? sql : sql.substring(0, spaceIndex));
        span.tag("sql.query", sql);
        parseServerIpAndPort(connection, span);
        span.start();
        return null;
    }

    @Override
    @Nullable
    public ResultSetInternalMethods postProcess(String sql, Statement interceptedStatement,
                                                ResultSetInternalMethods originalResultSet,
                                                Connection connection, int warningCount,
                                                boolean noIndexUsed, boolean noGoodIndexUsed,
                                                SQLException statementException) {
        final Span span = currentSpanInScope.get();
        currentSpanInScope.remove();
        if (span == null || span.isNoop()) {
            return null;
        }

        if (statementException != null) {
            span.tag("error", Integer.toString(statementException.getErrorCode()));
        }
        span.finish();
        return null;
    }

    /**
     * MySQL exposes the host connecting to, but not the port. This attempts to get the port from the
     * JDBC URL. Ex. 5555 from {@code jdbc:mysql://localhost:5555/database}, or 3306 if absent.
     */
    static void parseServerIpAndPort(Connection connection, Span span) {
        try {
            final URI url = URI.create(connection.getMetaData().getURL().substring(5)); // strip "jdbc:"
            String remoteServiceName = connection.getProperties().getProperty("zipkinServiceName");
            if (remoteServiceName == null || remoteServiceName.isEmpty()) {
                final String databaseName = connection.getCatalog();
                if (databaseName != null && !databaseName.isEmpty()) {
                    remoteServiceName = "mysql-" + databaseName;
                } else {
                    remoteServiceName = "mysql";
                }
            }
            span.remoteServiceName(remoteServiceName);
            final String host = connection.getHost();
            if (host != null) {
                span.remoteIpAndPort(host, url.getPort() == -1 ? 3306 : url.getPort());
            }
        } catch (Exception e) {
            // remote address is optional
        }
    }

    @Override
    public boolean executeTopLevelOnly() {
        return true; // True means that we don't get notified about queries that other interceptors issue
    }

    @Override
    public void init(Connection conn, Properties props) {
        // Don't care
    }

    @Override
    public void destroy() {
        // Don't care
    }
}