利用MIME类型根据apk路径自动安装apk之application/vnd.android.package-archive

来源：互联网发布：linux 设置系统时区编辑：程序博客网时间：2024/04/29 11:00

根据apk路径自动安装apk

    String fileName = Environment.getExternalStorageDirectory() + realshow.apk;    Uri uri = Uri.fromFile(new File(fileName));    //设置intent的Action属性    Intent intent = new Intent(Intent.ACTION_VIEW);    //设置intent的data和Type属性。    //自动安装apk    intent.setDataAndType(Uri, application/vnd.Android.package-archive");    startActivity(intent);

这里intent.setDataAndType(Uri, application/vnd.Android.package-archive”);中application/vnd.Android.package-archive的作用是什么？从setDataAndType方法的参数类型来看，它应该是一个type，下面具体看一下。

根据文件后缀名获得对应的MIME类型

/** * 根据文件后缀名获得对应的MIME类型。 * @param file */ private String getMIMEType(File file) {      String type="*/*";     String fName = file.getName();     //获取后缀名前的分隔符"."在fName中的位置。     int dotIndex = fName.lastIndexOf(".");     if(dotIndex < 0){         return type;     }     /* 获取文件的后缀名*/     String end=fName.substring(dotIndex,fName.length()).toLowerCase();     if(end=="")return type;     //在MIME和文件类型的匹配表中找到对应的MIME类型。     for(int i=0;i<MIME_MapTable.length;i++){         if(end.equals(MIME_MapTable[i][0]))             type = MIME_MapTable[i][1];     }            return type; }

这边出现了一个MIME_MapTable，从代码看来它似乎表明了与文件类型之间的某种关系，我们接着研究。

MIME_MapTable

什么是MIME

根据百度百科的解释：MIME：全称Multipurpose Internet Mail Extensions，多功能Internet 邮件扩充服务。它是一种多用途网际邮件扩充协议，在1992年最早应用于电子邮件系统，但后来也应用到浏览器。MIME类型就是设定某种扩展名的文件用一种应用程序来打开的方式类型，当该扩展名文件被访问的时候，浏览器会自动使用指定应用程序来打开。多用于指定一些客户端自定义的文件名，以及一些媒体文件打开方式。

MIME_MapTable其实是所有文件的后缀名所对应的MIME类型的一个String数组：

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.openxmlformatsofficedocument.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.openxmlformatsofficedocument.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"},             {"",        "*/*"}           };

从列表中可以看出，application/vnd.android.package-archive其实表示的是”.apk”，所以

    intent.setDataAndType(Uri, application/vnd.Android.package-archive");    startActivity(intent);

其实是通过合适的方式打开了一个”.apk”类型的文件——自动安装了这个apk。

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