问题：
Tomcat服务器环境，打开浏览器下载 xls、rar文件时直接以浏览器打开并出现乱码。
解决办法：
其实很简单，只需要在Tomcat 5.0_HOME/conf/web.xml文件中添加几行代码即可。
<mime-mapping>
<extension>doc</extension>
<mime-type>application/msword</mime-type>
</mime-mapping>
<mime-mapping>
<extension>xls</extension>
<mime-type>application/vnd.ms-excel</mime-type>
</mime-mapping>
<mime-mapping>
<extension>ppt</extension>
<mime-type>application/vnd.ms-powerpoint</mime-type>
</mime-mapping>
<mime-mapping>
<extension>zip</extension>
<mime-type>application/zip</mime-type>
</mime-mapping>
<mime-mapping>
<extension>rar</extension>
<mime-type>application/rar</mime-type>
</mime-mapping>
<mime-mapping>
<extension>msi</extension>
<mime-type>application/msi</mime-type>
</mime-mapping>
<mime-mapping>
<extension>cab</extension>
<mime-type>application/cab</mime-type>
</mime-mapping>
另外，代码可以下载mime.txt,web.xml文件，还有，别忘了，
1）重启TOMCAT
2）清除你本地的IE缓存,办法是：工具--Internet选项--浏览历史纪录--删除。
再打开RAR的文件时就正常下载了。