@Override
    public String toString() {
        return "ConnectionConfig{" +
                "jdbcDriverClassName='" + className + '\'' +
                ", jdbcDriverUrl='" + url + '\'' +
                ", jdbcDriverUsername='" + user + '\'' +
                '}';
    }
Merges the non-null values of other into this. If other is null return this.
stroom-config/stroom-config-common/src/main/java/stroom/config/common/ConnectionConfig.java