android文件下载自动安装或打开

最近做了几个项目，花点时间沉淀一下学到的知识。

1. 多线程下载文件及UI刷新
   断点续传下载文件网上的文章很多，在这里就不过多叙述了，在android里面控制UI的变化就比较麻烦了，用户在按下home键离开程序，再返回来，进度条的变化或者按钮的变化等等都要做出适当的控制，在用线程下载的时候，离开程序的时候线程并不会关闭，使用多个全局静态的handler，控制多个不同线程的UI刷新，可以实现相应的效果。（当然肯定还有更好的方式）

public static SparseArray messageArray = new SparseArray<>();

DownloadHandler类

public class DownloadHandler extends Handler {
    private TextView btn;
    private static final int FINISH = 2;
    private static final int DOWNLOADING = 1;
    private static final int OPEN = 0;
    public void setBtn(TextView btn) {
        this.btn = btn;
    }

    @Override
    public void handleMessage(Message msg) {
        super.handleMessage(msg);
        switch (msg.what) {
            case FINISH:
                btn.setText("打 开");
                //btn.setTextColor(Color.parseColor("#E8BB5B"));
                break;
            case DOWNLOADING:
                btn.setText("下载中...");
                btn.setClickable(false);
                //btn.setBackgroundColor(Color.parseColor("#969696"));
                break;
            case OPEN:
                break;
        }
    }
}

下载过程中发出Mesage,标记状态，下载完成时同理

 Message msg = new Message();
 msg.arg1 = position;
 Constant.NOTE_DOWNLOAD = DOWNLOADING;
 msg.what = Constant.NOTE_DOWNLOAD;
 Constant.messageArray.get(position).sendMessage(msg);

1. 下载完成自动打开或安装
   文件下载完成后，会调用手机自带软件打开它或者安装它，代码如下

/**
     * 根据文件后缀名匹配MIMEType
     * @param file
     * @return
     */
    public static String getMIMEType(File file) {
        String type ="*/*";
        String name = file.getName();
        int index = name.lastIndexOf('.');
        if (index < 0) {
            return type;
        }

        String end = name.substring(index,name.length()).toLowerCase();
        if (TextUtils.isEmpty(end)) return type;

        for (int i = 0;i < MIME_MapTable.length;i++) {
            if (end.equals(MIME_MapTable[i][0]))
                type = MIME_MapTable[i][1];
        }
        return type;
    }

    /**
     * 打开文件
     * @param context
     * @param file 文件
     */
    public static void openFile(Context context,File file) {
        Intent intent = new Intent();
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.setAction(Intent.ACTION_VIEW);
        String type= getMIMEType(file);
        //设置intent的data和Type属性。
        intent.setDataAndType(Uri.fromFile(file), type);
        context.startActivity(intent);
    }

    /**
     * 自动安装apk文件
     * @param context
     * @param file
     */
    public static void openApk(Context context,File file) {
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.setDataAndType(Uri.fromFile(file), "application/vnd.android.package-archive");
        context.startActivity(intent);
    }

    private static final String[][] MIME_MapTable={
            {".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"},
            {"",        "*/*"}
    };