自动生成不重复的订单id

@ApiModel(value = "订单")
@Entity
@EntityListeners(AuditingEntityListener.class)
public class Order implements Serializable {
    private static final long serialVersionUID = -44480262996409913L;
    @Id
    @Column(name = "id", nullable = false, length = 100)
    @GeneratedValue(generator = GeneratorConst.ID_GENERATOR_NAME)
    @GenericGenerator(name = GeneratorConst.ID_GENERATOR_NAME, strategy = GeneratorConst.ID_STRATEGY, parameters = {
            @org.hibernate.annotations.Parameter(name = GeneratorConst.ID_SEQ_DATE, value = "yyyyMMdd"),
            @org.hibernate.annotations.Parameter(name = GeneratorConst.ID_SEQ_FMT_WIDTH, value = "14"),
            @org.hibernate.annotations.Parameter(name = org.hibernate.id.enhanced.TableGenerator.SEGMENT_COLUMN_PARAM, value = "ID"),
            @org.hibernate.annotations.Parameter(name = org.hibernate.id.enhanced.TableGenerator.SEGMENT_VALUE_PARAM, value = "oderId"),
            @org.hibernate.annotations.Parameter(name = org.hibernate.id.enhanced.TableGenerator.VALUE_COLUMN_PARAM, value = "seq"),
            @org.hibernate.annotations.Parameter(name = org.hibernate.id.enhanced.TableGenerator.TABLE_PARAM, value = "tseq"),
            @org.hibernate.annotations.Parameter(name = TableGenerator.INCREMENT_PARAM, value = "1000") })
    private String orderId;
}

public class GeneratorConst {
	public final static String ID_STRATEGY = "com.util.AssignedSequenceGenerator";
	public final static String ID_GENERATOR_NAME = "orderGenerator";
	public final static String ID_SEQ_FMT_WIDTH = "fmtWidth";
	public final static String ID_SEQ_DATE = "dateWidth";

}

import com.ruyicai.edu.constant.GeneratorConst;
import org.apache.commons.lang3.time.FastDateFormat;
import org.hibernate.HibernateException;
import org.hibernate.MappingException;
import org.hibernate.engine.spi.SharedSessionContractImplementor;
import org.hibernate.id.Configurable;
import org.hibernate.id.PersistentIdentifierGenerator;
import org.hibernate.id.enhanced.TableGenerator;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.type.IntegerType;
import org.hibernate.type.Type;

import java.io.Serializable;
import java.util.Date;
import java.util.Properties;

public class AssignedSequenceGenerator extends TableGenerator implements
		PersistentIdentifierGenerator, Configurable {

	private String prefix;
	private Integer fmtWidth;
	private FastDateFormat sdf;
	private Integer INCREMENT_PARAM = 0;

	@Override
	public void configure(Type type, Properties params, ServiceRegistry serviceRegistry)
			throws MappingException {
		super.configure(IntegerType.INSTANCE, params, serviceRegistry);
		if (params.containsKey(GeneratorConst.ID_SEQ_FMT_WIDTH))
			fmtWidth = new Integer(params.getProperty(GeneratorConst.ID_SEQ_FMT_WIDTH));
		if (params.containsKey(GeneratorConst.ID_SEQ_DATE))
			sdf = FastDateFormat.getInstance(params.getProperty(GeneratorConst.ID_SEQ_DATE));
		if (params.containsKey(TableGenerator.INCREMENT_PARAM))
			INCREMENT_PARAM = new Integer(params.getProperty(TableGenerator.INCREMENT_PARAM));
	}

	@Override
	public Serializable generate(SharedSessionContractImplementor session, Object obj)
			throws HibernateException {
		int seq = (Integer) super.generate(session, obj)+1+INCREMENT_PARAM;
		StringBuffer sbf = new StringBuffer();
		if (prefix != null) {
			sbf.append(prefix);
		}
		if (sdf != null) {
			Date now = new Date();
			sbf.append(sdf.format(now));
		}
		if (fmtWidth != null) {
			sbf.append(format(seq, fmtWidth));
		} else {
			sbf.append(seq);
		}
		return sbf.toString();
	}

	private String format(int num, int width) {
		if (num < 0)
			return "";
		StringBuffer sb = new StringBuffer();
		String s = "" + num;
		if (s.length() < width) {
			int addNum = width - s.length();
			for (int i = 0; i < addNum; i++) {
				sb.append("0");
			}
			sb.append(s);
		} else {
			return s.substring(s.length() - width, s.length());
		}
		return sb.toString();
	}
}

CREATE TABLE `tseq` (
  `ID` varchar(100) NOT NULL,
  `SEQ` bigint(20) DEFAULT NULL,
  `MEMO` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`ID`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;