打开window-preference -> General-Editors-File Associator
看到右边的.js下边就是设置默认打开方式了
转自百度知道:http://zhidao.baidu.com/link?url=wuTTVrO2WyxC56cusW4oSDuH7CkZ7zBlwAIO239eVk1XBH4rfD8HHVSl6ThKiUE3JRgynPtU8RzmCp4HxAei3K