这种方式是最简单的方式，局限于你手机上必须提前已经安装过打开word的相关应用。

 String path = Environment.getExternalStorageDirectory().getPath().concat("/").concat("myDoc").concat("/").concat("a.doc");
                File docFile = new File(path);
                Intent in = new Intent("android.intent.action.VIEW");
                in.addCategory("android.intent.category.DEFAULT");
                Uri data;
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                    // "net.csdn.blog.ruancoder.fileprovider"即是在清单文件中配置的authorities
                    data = FileProvider.getUriForFile(mContext, "com.sailing.fileprovider", docFile);
                    // 给目标应用一个临时授权
                    in.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
                } else {
                    data = Uri.fromFile(docFile);
                }
                in.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                in.setDataAndType(data, "application/msword");
                startActivity(in);

该内容涉及两个重要的知识点：

1.判断你使用的androidsdk是否大于23，大于23时候是不能直接读取本地的文件的，文件需要使用fileprovider,URI需要特殊处理。

                Uri data;
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                    // "net.csdn.blog.ruancoder.fileprovider"即是在清单文件中配置的authorities
                    data = FileProvider.getUriForFile(mContext, "com.sailing.fileprovider", docFile);
                    // 给目标应用一个临时授权
                    in.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
                } else {
                    data = Uri.fromFile(docFile);
                }

2.打开doc文档需要使用setDataAndType方法设置对应的值：”application/msword”;

 in.setDataAndType(data, "application/msword");

其余格式的文件DataAndType值如下：

   private final String[][] MIME_MapTable = {
            //{后缀名，MIME类型}
            {".3gp", "video/3gpp"},
            {".apk", "application/vnd.android.package-archive"},
            {".asf", "video/x-ms-asf"},
            {".avi", "video/x-msvideo"},
            {".bin", "application/octet-stream"},
            {".bmp", "image/bmp"},
            {".c", "text/plain"},
            {".class", "application/octet-stream"},
            {".conf", "text/plain"},
            {".cpp", "text/plain"},
            {".doc", "application/msword"},
            {".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
            {".xls", "application/vnd.ms-excel"},
            {".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
            {".exe", "application/octet-stream"},
            {".gif", "image/gif"},
            {".gtar", "application/x-gtar"},
            {".gz", "application/x-gzip"},
            {".h", "text/plain"},
            {".htm", "text/html"},
            {".html", "text/html"},
            {".jar", "application/java-archive"},
            {".java", "text/plain"},
            {".jpeg", "image/jpeg"},
            {".jpg", "image/jpeg"},
            {".js", "application/x-javascript"},
            {".log", "text/plain"},
            {".m3u", "audio/x-mpegurl"},
            {".m4a", "audio/mp4a-latm"},
            {".m4b", "audio/mp4a-latm"},
            {".m4p", "audio/mp4a-latm"},
            {".m4u", "video/vnd.mpegurl"},
            {".m4v", "video/x-m4v"},
            {".mov", "video/quicktime"},
            {".mp2", "audio/x-mpeg"},
            {".mp3", "audio/x-mpeg"},
            {".mp4", "video/mp4"},
            {".mpc", "application/vnd.mpohun.certificate"},
            {".mpe", "video/mpeg"},
            {".mpeg", "video/mpeg"},
            {".mpg", "video/mpeg"},
            {".mpg4", "video/mp4"},
            {".mpga", "audio/mpeg"},
            {".msg", "application/vnd.ms-outlook"},
            {".ogg", "audio/ogg"},
            {".pdf", "application/pdf"},
            {".png", "image/png"},
            {".pps", "application/vnd.ms-powerpoint"},
            {".ppt", "application/vnd.ms-powerpoint"},
            {".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
            {".prop", "text/plain"},
            {".rc", "text/plain"},
            {".rmvb", "audio/x-pn-realaudio"},
            {".rtf", "application/rtf"},
            {".sh", "text/plain"},
            {".tar", "application/x-tar"},
            {".tgz", "application/x-compressed"},
            {".txt", "text/plain"},
            {".wav", "audio/x-wav"},
            {".wma", "audio/x-ms-wma"},
            {".wmv", "audio/x-ms-wmv"},
            {".wps", "application/vnd.ms-works"},
            {".xml", "text/plain"},
            {".z", "application/x-compress"},
            {".zip", "application/x-zip-compressed"},
            {"", "*/*"}
    };