POI操作Excel报错java.lang.NoSuchMethodError

1、检查报错日志如下

2、定位错误

1、可能是编码出问题，检查编码

3、生成EXCEL文件类是否有如下编码：

response.setContentType("application/x-msdownload");

response.setCharacterEncoding("utf-8"); 

response.setHeader("Content-Disposition", "attachment;filename=" + new String( fileName.getBytes("gb2312"), "ISO8859-1" ));

4、检查导入poi的包是否存在多个版本，删除多余版本。

5、<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>  

<dependency>  

<groupId>org.apache.poi</groupId>  

<artifactId>poi</artifactId>  

<version>3.17</version>  

</dependency>

6、如果不确定自己引用的是哪个包，可以用一下代码检测class文件走哪个jar包

7、检测class文件代码：

ClassLoader classloader =

   org.apache.poi.poifs.filesystem.POIFSFileSystem.class.getClassLoader();

URL res = classloader.getResource(

             "org/apache/poi/poifs/filesystem/POIFSFileSystem.class");

String path = res.getPath();

System.out.println("POI Core came from " + path);

classloader = org.apache.poi.POIXMLDocument.class.getClassLoader();

res = classloader.getResource("org/apache/poi/POIXMLDocument.class");

path = res.getPath();

System.out.println("POI OOXML came from " + path);

classloader = org.apache.poi.hslf.HSLFSlideShow.class.getClassLoader();

res = classloader.getResource("org/apache/poi/hslf/HSLFSlideShow.class");

path = res.getPath();

System.out.println("POI Scratchpad came from " + path);

8、将旧的jar从Java build path中删除掉，把workspace里面的包删了再把project clean一下，然后重新部署。