问题描述

使用apache.poi读取.xls文件时有The content of an excel record cannot exceed 8224 bytes的报错。待读取的文件的内容也是通过apache.poi写入的，我的文件修改步骤是先删除页签然后写入页签（页签名是保持不变的），这样一次修改的结果也是符合我的预期的，但是某次程序读取文件时就出现了下面的报错，而且手动也打不开文件了。

Exception in thread "main" org.apache.poi.util.RecordFormatException: The content of an excel record cannot exceed 8224 bytes
	at org.apache.poi.hssf.record.RecordInputStream.nextRecord(RecordInputStream.java:222)
	at org.apache.poi.hssf.record.RecordFactoryInputStream.nextRecord(RecordFactoryInputStream.java:253)
	at org.apache.poi.hssf.record.RecordFactory.createRecords(RecordFactory.java:494)
	at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:356)
	at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:413)
	at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:394)
	at com.mark.learning.bug.excel.ExcelXls.addSheet(ExcelXls.java:28)
	at com.mark.learning.bug.excel.ExcelXls.main(ExcelXls.java:84)

版本

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.17</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.17</version>
        </dependency>

定位：打印size最大的Record

既然提示某一个Record超过了上限了，那我就把这个内容打印出来看看。最新定位到ExternSheetRecord 类的_list属性。

第267个record的size：6066
[EXTERNSHEET]
   numOfRefs     = 1010
refrec         #0: extBook=0 firstSheet=-1 lastSheet=-1
refrec         #1: extBook=0 firstSheet=-1 lastSheet=-1
refrec         #2: extBook=0 firstSheet=-1 lastSheet=-1
refrec         #3: extBook=0 firstSheet=-1 lastSheet=-1
refrec         #4: extBook=0 firstSheet=-1 lastSheet=-1
refrec         #5: extBook=0 firstSheet=-1 lastSheet=-1

public class ExternSheetRecord extends StandardRecord {

    public final static short sid = 0x0017;
	private final List<RefSubRecord> _list;//这里有很多的记录信息

定位：RefSubRecord

RefSubRecord记录是什么信息？什么时候进行初始化？我在构造函数打了一个断点，发现每当删除一个页签或者新增一个页签就会创建RefSubRecord页签


这里有意思的是删除页签的时候会把对应索引的记录的firstSheetIndex和lastSheetIndex修改为-1。但是后面新增的从时候又尝试根据这两个变量找到对应的索引

这样就导致到了ExternSheetRecord 类的_list属性会随着程序的运行不断的增长！

解决

1.直接替换文件类型将.xls换位新版的.xlsx
2.升级版本apache.poi版本，我尝试升级为3.8版本的时候发现就没有这个问题了，原因是再3.8中删除的删除的页签的时候不会修改RefSubRecord的信息
3.17的删除逻辑

3.8的删除逻辑 (少了上面红框的内容)

代码

复现...exceed 8224 bytes报错的代码

public class ExcelTest {

    private static int createSheetCnt = 0;
    private static final String path = "C:\\Users\\Desktop\\test2.xls";

    public void addSheet() {
        try {
            File file = new File(path);
            FileInputStream in = new FileInputStream(file);
            HSSFWorkbook workbook = new HSSFWorkbook(in);
            in.close();

            String sheetName = "test";
            int sheetIndex = workbook.getSheetIndex(sheetName);
            if (sheetIndex >= 0) {
                //页签存在删除页签
                workbook.removeSheetAt(sheetIndex);
            }
            //新建一个页签写入文件
            workbook.createSheet(sheetName);
            FileOutputStream fileOut = new FileOutputStream(path);
            workbook.write(fileOut);
            fileOut.close();

            System.out.println("创建页签次数：" + ++createSheetCnt);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Test
    public void test() {
        for (int i = 0; i < 10000; i++) {
            addSheet();
        }
    }
}

打印record信息的方法

    public void printlnRecords() {
        try {
            File file = new File(path);
            FileInputStream in = new FileInputStream(file);
            HSSFWorkbook workbook = new HSSFWorkbook(in);
            in.close();

            InternalWorkbook internalWorkbook = workbook.getInternalWorkbook();
            List<Record> records = internalWorkbook.getRecords();
            System.out.println("records size:" + records.size());
            int maxIndex = 0;
            int maxRecordSize = 0;
            for (int i = 0; i < records.size(); i++) {
                Record record = records.get(i);
                int recordSize = record.getRecordSize();

                System.out.println("第" + i + "个record的size：" + recordSize);
                System.out.println(record);
                System.out.println();

                if (recordSize > maxRecordSize) {
                    maxRecordSize = recordSize;
                    maxIndex = i;
                }
            }
            System.out.println("第" + maxIndex + "个record的有最大size：" + maxRecordSize);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }