再用easyExcel导出的时候，写到如下代码报错

EasyExcel.write(response.getOutputStream(), Excel.class).sheet("导出信息").doWrite(list);

报如下几种错误，奇怪的是每次都报的不一样

java.lang.NoClassDefFoundError: Could not initialize class com.alibaba.excel.write.ExcelBuilderImpl

java.lang.ClassNotFoundException: org.apache.poi.util.TempFileCreationStrategy

java.lang.NoClassDefFoundError: Could not initialize class com.alibaba.excel.write.ExcelBuilderImpl

后来排查很久发现是easyExcel版本是2.2.3，我用的poi版本是3.9，导致有冲突，网上查3.17兼容，或则升级更高的4.1.2

<!--easyExcel-->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>easyexcel</artifactId>
    <version>2.2.3</version>
</dependency>

<!-- POI导入导出 -->
<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>

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

重新导出发现有报了一个错误如下

com.alibaba.excel.exception.ExcelGenerateException: java.lang.NoClassDefFoundError: org/apache/commons/collections4/ListValuedMap

发现是我船的数据是集合要处理，引用新的依赖commons-collections4

<dependency>
   <groupId>org.apache.commons</groupId>
   <artifactId>commons-collections4</artifactId>
   <version>4.1</version>
</dependency>

如果还报如下错误：

com.alibaba.excel.exception.ExcelGenerateException: java.lang.NoClassDefFoundError: net/sf/cglib/beans/BeanMap

缺少cglib代理包所致，就引入cglib依赖

<dependency>
   <groupId>cglib</groupId>
   <artifactId>cglib</artifactId>
   <version>3.1</version>
</dependency>

总结：poi版本与easyExcel版本一定要兼容。