最近在項目中有這麼一段代碼:下載服務器基礎業務數據進行本地批量插入操作,因項目中使用mybatis進行持久化操作,故直接考慮使用mybatis的批量插入功能。
1.以下是Mapper接口的部分代碼
public interface PrintMapper { @InsertProvider(type = PrintMapperProvider.class,method = "insertAllLotWithVehicleCode4H2") void insertAllLotWithVehicleCode(List<LotWithVehicleCodeBO> lotWithVehicleCodes); }
2.對應MapperProvider中函數片段
public String insertAllLotWithVehicleCode4H2(Map<String,List<LotWithVehicleCodeBO>> map) { List<LotWithVehicleCodeBO> 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層
@Transactionalpublic void synchLotWithVehicleCodeToLocalDB(List<LotWithVehicleCodeBO> lotWithVehicleCodeBOs) { if(null != lotWithVehicleCodeBOs && lotWithVehicleCodeBOs.size()>0) { printMapper.insertAllLotWithVehicleCode(lotWithVehicleCodeBOs); } }
程序上線的時候沒有發生問題,在業務量猛增的時候,大約同時執行500條以上的時候程序就開始報錯:
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
異常已指明SQL語句構建問題,DEBUG進去:
問題根源:
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<size-1) sb.append(","); }
當size達到3位數以上時構建出的message為:
(#{list[1,000].lotCode },#{list[1,000].productVehicleCode })
解決辦法:messageFormat.format(new Object[]{i+""}