Excel file corrupt when copied from src to target in Eclipse IDE

Thanks to the above answers we found out how to deal with the problem:

    <plugin>
      <artifactId>maven-resources-plugin</artifactId>
      <version>2.5</version>
      <configuration>
        <encoding>UTF-8</encoding>
        <nonFilteredFileExtensions>
          <nonFilteredFileExtension>xls</nonFilteredFileExtension>
        </nonFilteredFileExtensions>
      </configuration>
    </plugin>

I had the same issue, and it was cause by the Maven resources plugin which filtered and altered my Excel files.

To prevent this to happen, add something like this (see the Maven doc) :

<build>               
       <resources>
           <resource>
               <filtering>true</filtering>
               <directory>src/test/resources</directory>
               <excludes>
                   <exclude>**/*.xls</exclude>
               </excludes>
         </resource>
...

UPDATE : Copy in resources, but don't filter

<resources>
      <resource>
        <directory>src/test/resources</directory>
        <filtering>true</filtering>
        <excludes>
          <exclude>**/*.xls</exclude>
        </excludes>
      </resource>
      <resource>
        <directory>src/test/resources</directory>
        <filtering>false</filtering>
        <includes>
          <include>**/*.xls</include>
        </includes>
      </resource>
      ...
    </resources>