下载apk

布局

<Button
        android:id="@+id/bt_download"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/bt_upload"
        android:text="下载"/>

代码   先写工具类，判断网络

public class NetWorkUtils {
    //判断网络连接状态
    public static boolean isNetWorkIsAvailable(Context context) {
        //网络连接管理器
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        //获取网络信息
        NetworkInfo info = connectivityManager.getActiveNetworkInfo();
        if (info != null) {
            return true;
        }
       /* if (info.isConnected()) {
            return true;
        }*/


        return false;
    }

    //判断是否是wifi
    public static boolean isWifi(Context context) {
        //网络连接管理器
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        //获取网络信息
        NetworkInfo info = connectivityManager.getActiveNetworkInfo();
        if (info != null && info.getType() == connectivityManager.TYPE_WIFI) {
            return true;
        }

        return false;
    }

    //判断是否是手机流量
    public static boolean isMobile(Context context) {
        //网络连接管理器
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        //获取网络信息
        NetworkInfo info = connectivityManager.getActiveNetworkInfo();
        if (info != null && info.getType() == connectivityManager.TYPE_MOBILE) {
            return true;
        }

        return false;
    }

}

MainActivity 方法

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //找控件
        Button bt_upload = (Button) findViewById(R.id.bt_upload);
        Button bt_download = (Button) findViewById(R.id.bt_download);
        bt_upload.setOnClickListener(this);
        bt_download.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.bt_upload:
                uploadPic();

                break;
            case R.id.bt_download:
                boolean workIsAvailable = NetWorkUtils.isNetWorkIsAvailable(MainActivity.this);
                if (!workIsAvailable) {
                    Toast.makeText(MainActivity.this, "网络未连接，请设置网络", Toast.LENGTH_SHORT).show();
                    Intent intent = new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS);
                    startActivity(intent);
                } else {
                    //连接成功下载
                    Toast.makeText(MainActivity.this, "网络连接成功", Toast.LENGTH_SHORT).show();

                    download();
                }

                break;
        }
    }

    //下载
    private void download() {
        final String[] items = {"wifi", "手机流量"};
        new AlertDialog.Builder(this).setTitle("网络选择").setIcon(R.mipmap.ic_launcher).setSingleChoiceItems(items, -1, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

                switch (which) {
                    case 0:
                        //wifi下 下载apk
                        downloadApk();
                        break;
                    case 1:
                        //手机流量下提醒用户
                        boolean mobile = NetWorkUtils.isMobile(MainActivity.this);
                        if (mobile) {
                            Toast.makeText(MainActivity.this, "现在未使用wifi,将耗用手机流量", Toast.LENGTH_SHORT).show();
                            Intent wifiSettingsIntent = new Intent("android.settings.WIFI_SETTINGS");
                            startActivity(wifiSettingsIntent);

                        }

                        break;
                }
                dialog.dismiss();
            }
        }).show();
    }

    //下载apk
    private void downloadApk() {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("版本更新");
        builder.setMessage("现在检测到新版本，是否更新？");
        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                updateApk();
            }
        });
        builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });
        builder.create();
        builder.show();


    }

    //版本更新
    private void updateApk() {
        String url = "http://169.254.249.24:8080/08web/app.apk";
        RequestParams params = new RequestParams(url);
        //保存到sdcard
        params.setSaveFilePath(Environment.getExternalStorageDirectory() + "/bawei/");
        //自动文件命令
        params.setAutoRename(true);
        //下载
        x.http().post(params, new Callback.ProgressCallback<File>() {
            @Override
            public void onWaiting() {

            }

            @Override
            public void onStarted() {

            }

            @Override
            public void onLoading(long total, long current, boolean isDownloading) {

            }

            @Override
            public void onSuccess(File result) {
                Intent intent = new Intent(Intent.ACTION_VIEW);
                intent.setDataAndType(Uri.fromFile(result), "application/vnd.android.package-archive");
                startActivity(intent);
            }

            @Override
            public void onError(Throwable ex, boolean isOnCallback) {

            }

            @Override
            public void onCancelled(CancelledException cex) {

            }

            @Override
            public void onFinished() {

            }
        });


    }