最近在项目中有这么一段代码:下载服务器基础业务数据进行本地批量插入操作,因项目中使用mybatis进行持久化操作,故直接考虑使用mybatis的批量插入功能。
1.以下是Mapper接口的部分代码
public interface PrintMapper { @InsertProvider(type = PrintMapperProvider.class,method = "insertAllLotWithVehicleCode4H2") void insertAllLotWithVehicleCode(ListlotWithVehicleCodes); }
2.对应MapperProvider中函数片段
public String insertAllLotWithVehicleCode4H2(Map> map) { List lotWithVehicleCodeBOs = map.get("list"); StringBuilder sb = new StringBuilder("INSERT INTO MTC_LOT_WITH_VEHICLE_CODE (LOT_CODE,PRODUCT_VEHICLE_CODE) VALUES "); MessageFormat messageFormat = new MessageFormat("(" + "#'{'list[{0}].lotCode }," + "#'{'list[{0}].productVehicleCode }" + ")"); int size = lotWithVehicleCodeBOs.size(); for (int i = 0; i < size; i++) { sb.append(messageFormat.format(new Object[]{i})); if (i < size - 1) sb.append(","); } return sb.toString(); }
3.service层
@Transactionalpublic void synchLotWithVehicleCodeToLocalDB(ListlotWithVehicleCodeBOs) { if(null != lotWithVehicleCodeBOs && lotWithVehicleCodeBOs.size()>0) { printMapper.insertAllLotWithVehicleCode(lotWithVehicleCodeBOs); } }
程序上线的时候没有发生问题,在业务量猛增的时候,大约同时执行500条以上的时候程序就开始报错:
Caused by: org.apache.ibatis.builder.BuilderException: Improper inline parameter map format. Should be: #{propName,attr1=val1,attr2=val2} at org.apache.ibatis.builder.SqlSourceBuilder$ParameterMappingTokenHandler.buildParameterMapping(SqlSourceBuilder.java:89) at org.apache.ibatis.builder.SqlSourceBuilder$ParameterMappingTokenHandler.handleToken(SqlSourceBuilder.java:43) at org.apache.ibatis.parsing.GenericTokenParser.parse(GenericTokenParser.java:25) at org.apache.ibatis.builder.SqlSourceBuilder.parse(SqlSourceBuilder.java:24) at org.apache.ibatis.builder.annotation.ProviderSqlSource.createSqlSource(ProviderSqlSource.java:57) ... 61 more
异常已指明SQL语句构建问题,DEBUG进去:
问题根源:
MessageFormat messageFormat = new MessageFormat("(" + "#'{'list[{0}].lotCode }," + "#'{'list[{0}].productVehicleCode }," + ")"); int size = lotWithVehicleCodeBOs.size(); for (int i = 0; i < size; i++) { sb.append(messageFormat.format(new Object[]{i})); if (i当size达到3位数以上时构建出的message为:
(#{list[1,000].lotCode },#{list[1,000].productVehicleCode })解决办法:messageFormat.format(new Object[]{i+""}