/**
下载APK细节
1、点击升级后对话框不消失，再次点击时不能重复下载
2、下载过程中退出APP，下次进入应用后要重新下载（因为可能不完整）
3、下载过程中退出APP（或下载完成后退出），如果APK已经下载完毕，则下次进入应用后不再下载
4、如果下载的APK被清除了，要重新下载
5、断网后重新连接或切换网络后不受影响
 */
public class MainActivity extends Activity {
    private TextView textView;
    private DownloadCompleteReceiver receiver = null;
    private String url = "http://113.107.216.43/imtt.dd.qq.com/16891/BD5BA98958C0FEC9D88FB65BF5534A3B.apk?mkey=581c007d0e1baac8&f=8a5d&c=0&fsname=com.bcb_2.0.2_52.apk&csr=4d5s&p=.apk";
    private String fileName;
    private AlertDialog dialog;
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        textView = new TextView(this);
        setContentView(textView);
        fileName = "福利金融-" + Utiles.getVersionCode(this) + ".apk";
        textView.setText("文件名：" + fileName //
                + "\n文件路径：" + Utiles.getApkFile(fileName).getPath() //
                + "\n是否已下载过此版本的安装包：" + Utiles.getIsDownloaded(this, fileName)//
                + "\n是否已下载时退出了：" + Utiles.getIsFinishedWhenDownloading(this));
        showVersionDialog();
    }
    private void showVersionDialog() {
        AlertDialog.Builder ibuilder = new AlertDialog.Builder(this);
        ibuilder.setTitle("版本更新啦！");
        ibuilder.setMessage("优化用户界面，界面更好看\n修复所有已经的bug");
        ibuilder.setNegativeButton("退出应用", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
                dialog = null;
                finish();
            }
        });
        ibuilder.setPositiveButton("立即更新", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                File file = Utiles.getApkFile(fileName);
                if (Utiles.getIsDownloaded(MainActivity.this, fileName)) {//已下载完毕
                    if (file == null || !file.exists()) {
                        Utiles.clearSP(MainActivity.this);//清空保存的两个数据
                        registerReceiver();//被删了，重新下载
                    } else Utiles.installApk(MainActivity.this, file);//否则，安装
                } else if (Utiles.getIsFinishedWhenDownloading(MainActivity.this)) {//上次在下载过程中退出了，下次进入应用时重新下载
                    registerReceiver();//重新下载
                } else if (file != null && file.exists()) {//正在下载
                    Toast.makeText(MainActivity.this, "正在下载，请稍后", Toast.LENGTH_SHORT).show();
                } else {//没下载过
                    registerReceiver();
                }
            }
        });
        dialog = ibuilder.create();
        dialog.setCanceledOnTouchOutside(false);
        dialog.setCancelable(false);
        dialog.show();
    }
    private void registerReceiver() {
        receiver = new DownloadCompleteReceiver();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(DownloadManager.ACTION_DOWNLOAD_COMPLETE);//下载完成的动作
        registerReceiver(receiver, intentFilter);
        Utiles.downLoadFile(MainActivity.this, url, fileName);//开始下载
    }
    class DownloadCompleteReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            if (intent.getAction().equals(DownloadManager.ACTION_DOWNLOAD_COMPLETE)) {
                Toast.makeText(MainActivity.this, "下载完毕", Toast.LENGTH_SHORT).show();
                textView.append("下载完毕");
                Utiles.saveIsDownloaded(context, fileName);
                Utiles.installApk(context, Utiles.getApkFile(fileName));
                if (receiver != null) {
                    unregisterReceiver(receiver);
                    receiver = null;
                }
            }
        }
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (receiver != null) {//如果receiver不为空，说明正在下载APK包，即使应用退出了，也会继续下载
            unregisterReceiver(receiver);
            Utiles.saveIsFinishedWhenDownloading(this);//如果在下载过程中退出了，下次进入应用时重新下载
        }
    }
}

public class Utiles {
    public static final String SP_NAME = "version";
    public static final String FILE_PATH = "/fljr/apk";
    /**返回下载的APK文件*/
    public static File getApkFile(String fileName) {
        String filePath = Environment.getExternalStorageDirectory().getPath() + FILE_PATH + File.separator + fileName;
        return new File(filePath);
    }
    /**安装指定的APK包*/
    public static void installApk(Context context, File apkFile) {
        Intent mIntent = new Intent(Intent.ACTION_VIEW);
        mIntent.setDataAndType(Uri.fromFile(apkFile), "application/vnd.android.package-archive");
        mIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(mIntent);
    }
    /**获取VersionCode*/
    public static int getVersionCode(Context context) {
        try {
            PackageInfo packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
            return packageInfo.versionCode;
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
            return 0;
        }
    }
     /**清空SP的数据*/
    public static void clearSP(Context context) {
        SharedPreferences.Editor editor = context.getSharedPreferences(SP_NAME, 0).edit();
        editor.clear();
        editor.commit();
    }
    //******************************************************************************************
    /**记录是否在下载过程中退出了，如果在下载过程中退出了，下次进入应用时重新下载*/
    public static void saveIsFinishedWhenDownloading(Context context) {
        SharedPreferences.Editor editor = context.getSharedPreferences(SP_NAME, 0).edit();
        editor.putBoolean("finish", true);
        editor.commit();
    }
    /**是否在下载过程中退出了*/
    public static boolean getIsFinishedWhenDownloading(Context context) {
        return context.getSharedPreferences(SP_NAME, 0).getBoolean("finish", false);
    }
    //******************************************************************************************
    /**记录是否已下载过指定版本的APK包*/
    public static void saveIsDownloaded(Context context, String fileName) {
        SharedPreferences.Editor editor = context.getSharedPreferences(SP_NAME, 0).edit();
        editor.putBoolean(fileName, true);
        editor.commit();
    }
    /**查看是否已下载过指定版本的APK包*/
    public static boolean getIsDownloaded(Context context, String fileName) {
        return context.getSharedPreferences(SP_NAME, 0).getBoolean(fileName, false);
    }
    /**下载文件*/
    public static void downLoadFile(Context mContext, String url, String fileName) {
        DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url))//下载路径
                .setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE)//显示方式。默认，下载过程中显示，下载完成后自动消失
                .setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE)//网络设置
                .setDestinationInExternalPublicDir(FILE_PATH, fileName);//文件下载路径
        ((DownloadManager) mContext.getSystemService(Context.DOWNLOAD_SERVICE)).enqueue(request);
    }
}