easyExcel大数据量导出oom

easyExcel大数据量导出

异常信息

com.alibaba.excel.exception.ExcelGenerateException: java.lang.OutOfMemoryError: GC overhead limit exceededat com.alibaba.excel.write.ExcelBuilderImpl.fill(ExcelBuilderImpl.java:84)at com.alibaba.excel.ExcelWriter.fill(ExcelWriter.java:185)

原因，easyExcel在进行填充数据的时候比较耗内存容易造成oom
解决方案，把数据分批写入文件,部分代码

        ExcelWriter excelWriter = null;ByteArrayOutputStream outputStream = new ByteArrayOutputStream();try {// 创建填充配置FillConfig fillConfig = FillConfig.builder().forceNewRow(true).build();excelWriter = EasyExcel.write(outputStream).withTemplate(templateIn).build();// 创建Sheet对象WriteSheet sheet = EasyExcel.writerSheet(0).build();// 分批导出int totalSize = dataList.size();// 每次导入条数int limit = 20000;// 共分的次数int totalPages = totalSize / limit;if (totalPages % limit > 0) {totalPages++;}for (int i = 0; i < totalPages; i++) {if (i == totalPages - 1) {excelWriter.fill(dataList.subList(i * limit, dataList.size()), fillConfig, sheet);} else {excelWriter.fill(dataList.subList(i * limit, limit * (i + 1)), fillConfig, sheet);}}} finally {if (null != excelWriter) {// 关闭流excelWriter.finish();}try {outputStream.close();} catch (IOException e) {log.error("关闭文件流失败");}try {templateIn.close();} catch (IOException e) {log.error("关闭文件流失败");}}

验证：分批次写入文件，可以正常导出文件，并未出现oom
在导出excel数据之后，fullGc的时候并未第一时间回收数据集合，可以在finally手动回收数据对象

finally {if (!CollectionUtils.isEmpty(dataList)) {dataList.clear();}if (null != excelWriter) {// 关闭流excelWriter.finish();}try {outputStream.close();} catch (IOException e) {log.error("关闭文件流失败");}try {templateIn.close();} catch (IOException e) {log.error("关闭文件流失败");}}