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
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public interface PrintMapper{@InsertProvider(type = PrintMapperProvider.class,method = "insertAllLotWithVehicleCode4H2") void insertAllLotWithVehicleCode(List<LotWithVehicleCodeBO> lotWithVehicleCodes);} |
2.对应MapperProvider中函数片段
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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 ");"#'{'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
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@Transactionalpublic void synchLotWithVehicleCodeToLocalDB(List<LotWithVehicleCodeBO> lotWithVehicleCodeBOs){ 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：
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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：
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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(",");} |
当size达到3位数以上时构建出的message为：
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(#{list[1,000].lotCode },#{list[1,000].productVehicleCode }) |
解决办法：messageFormat.format(new Object[]{i+""}
