1、cell 内容最大长度 The maximum length of cell contents (text) is 32767 characters

一、问题描述

在导出一些数据抛：

java.lang.IllegalArgumentException: The maximum length of cell contents (text) is 32767 characters

at org.apache.poi.ss.usermodel.CellBase.checkLength(CellBase.java:309)

at org.apache.poi.ss.usermodel.CellBase.setCellValue(CellBase.java:290)

二、产生原因

根据日志异常栈提示：at org.apache.poi.ss.usermodel.CellBase.checkLength(CellBase.java:309)

定位到 CellBase 类 checkLength 方法 309 行

private void checkLength(String value) {// value值超过了 32767if(value.length() > getSpreadsheetVersion().getMaxTextLength()){final String message = String.format(Locale.ROOT,"The maximum length of cell contents (text) is %d characters",getSpreadsheetVersion().getMaxTextLength());throw new IllegalArgumentException(message);}
}

getSpreadsheetVersion().getMaxTextLength() 枚举源码类

public enum SpreadsheetVersion {/*** Excel97 format aka BIFF8* <ul>* <li>The total number of available rows is 64k (2^16)</li>* <li>The total number of available columns is 256 (2^8)</li>* <li>The maximum number of arguments to a function is 30</li>* <li>Number of conditional format conditions on a cell is 3</li>* <li>Number of cell styles is 4000</li>* <li>Length of text cell contents is 32767</li>* </ul>*/EXCEL97(0x10000, 0x0100, 30, 3, 4000, 32767),/*** Excel2007** <ul>* <li>The total number of available rows is 1M (2^20)</li>* <li>The total number of available columns is 16K (2^14)</li>* <li>The maximum number of arguments to a function is 255</li>* <li>Number of conditional format conditions on a cell is unlimited* (actually limited by available memory in Excel)</li>* <li>Number of cell styles is 64000</li>* <li>Length of text cell contents is 32767</li>* <ul>*/EXCEL2007(0x100000, 0x4000, 255, Integer.MAX_VALUE, 64000, 32767);private final int _maxRows;private final int _maxColumns;private final int _maxFunctionArgs;private final int _maxCondFormats;private final int _maxCellStyles;private final int _maxTextLength;private SpreadsheetVersion(int maxRows, int maxColumns, int maxFunctionArgs, int maxCondFormats, int maxCellStyles, int maxText) {_maxRows = maxRows;_maxColumns = maxColumns;_maxFunctionArgs = maxFunctionArgs;_maxCondFormats = maxCondFormats;_maxCellStyles = maxCellStyles;_maxTextLength = maxText;}/*** @return the maximum number of usable rows in each spreadsheet*/public int getMaxRows() {return _maxRows;}/*** @return the last (maximum) valid row index, equals to <code> getMaxRows() - 1 </code>*/public int getLastRowIndex() {return _maxRows - 1;}/*** @return the maximum number of usable columns in each spreadsheet*/public int getMaxColumns() {return _maxColumns;}/*** @return the last (maximum) valid column index, equals to <code> getMaxColumns() - 1 </code>*/public int getLastColumnIndex() {return _maxColumns - 1;}/*** @return the maximum number arguments that can be passed to a multi-arg function (e.g. COUNTIF)*/public int getMaxFunctionArgs() {return _maxFunctionArgs;}/*** @return the maximum number of conditional format conditions on a cell*/public int getMaxConditionalFormats() {return _maxCondFormats;}/*** @return the maximum number of cell styles per spreadsheet*/public int getMaxCellStyles() {return _maxCellStyles;}/**** @return the last valid column index in a ALPHA-26 representation*  (<code>IV</code> or <code>XFD</code>).*/public String getLastColumnName() {return CellReference.convertNumToColString(getLastColumnIndex());}/*** @return the maximum length of a text cell*/public int getMaxTextLength() {return _maxTextLength;}
}

三、解决方案

通过，反射去修改 SpreadsheetVersion 的 _maxTextLength 变量即可。

( 注：这里仅仅只是为了突破cell的内容限制而作修改，理论上，修改 final 变量肯定是不合理的 )

/*** 初始化 cell 内容长度*     cell 原本内容长度限制 32767  现修改为Integer.MAX_VALUE
*/
public static void initCellMaxTextLength() {SpreadsheetVersion excel2007 = SpreadsheetVersion.EXCEL2007;if (Integer.MAX_VALUE != excel2007.getMaxTextLength()) {Field field;try {field = excel2007.getClass().getDeclaredField("_maxTextLength");field.setAccessible(true);field.set(excel2007,Integer.MAX_VALUE);} catch (Exception e) {e.printStackTrace();}}}// 导出数据前调用
initCellMaxTextLength();