通过okhttp3下载文件实现APP版本更新

原文：https://blog.csdn.net/qq_34261214/article/details/77124729

概况

思路是这样的,首先在服务器上把已经签名打包的apk放上去,还有一份TXT文件，文件上写着相关的版本号，然后客户端通过对比版本号决定是否下载文件。下载后就打开安装界面安装。
这里写图片描述

第一步

把已经签名打包apk和txt文件放上到服务器上，版本号要和txt文件上的描述一致。Android Studio的版本号除了在manifests上，写上code和name(code是面向开发者，name就是用户所看到的版本号），那么我要更新的是2.0版本，那么我应该写2.0，并且要把访问网络和写入数据权限写上
这里写图片描述
还要在build.gradle(Module:app）上更改版本号，如果是用eclipse开发就不需要这一步

TXT文件的内容如下，第一行是版本号，第二行版本描述，第三行是apk的下载链接

第二步

服务器端已经完成，接下来是代码的实现。
我这里采用okhttp3+mvp模式实现下载文件，如果有对这种模式不清楚的可以看在MVP模式下使用OkHttp3和初试OkHttp3实现登录功能

Model层有更新版本描述实例UpdateInfo和Okhttp3的get和post方法
首先在Presenter上有查询版本号和下载apk这两个方法，这两个都是使用Get请求
在View上就需要有一个对应一个触发更新的按钮，显示最新版本的Toast,显示并询问是否更新的Dialog,和显示进度的ProgressDialog，一个跳转到安装界面的操作

Model层

首先要有updateInfo,一个版本信息的实例

public class UpdateInfo
{
        private String version;
        private String description;
        private String url; public String getVersion() { return version; } public void setVersion(String version) { this.version = version; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } }

另一个是Modle，包装着okhttp3的post和get方法，这里只需要get请求


    /**
     * get请求
     * @param address
     * @param callback
     */

    public void get(String address, okhttp3.Callback callback) { OkHttpClient client = new OkHttpClient(); FormBody.Builder builder = new FormBody.Builder(); FormBody body = builder.build(); Request request = new Request.Builder() .url(address) .build(); client.newCall(request).enqueue(callback); }

Presenter层

检查是否需要更新

 public void updateAPK() {
        model = Model.getInstance();
        model.get("TXT文件的url",new okhttp3.Callback(){ @Override public void onFailure(Call call, IOException e) { } @Override public void onResponse(Call call, Response response) throws IOException { String responseBody = response.body().string(); StringBuffer sb = new StringBuffer(); BufferedReader reader = null; UpdateInfo updateInfo = new UpdateInfo(); Log.d("版本", "onResponse: "+responseBody); reader = new BufferedReader(new StringReader(responseBody)); updateInfo.setVersion(reader.readLine());//把版本信息读出来 updateInfo.setDescription(reader.readLine()); updateInfo.setUrl(reader.readLine()); String new_version = updateInfo.getVersion(); Log.d("版本", "onResponse: "+updateInfo.getVersion()); Log.d("版本描述", "onResponse: "+updateInfo.getDescription()); Log.d("更新链接", "onResponse: "+updateInfo.getUrl()); String now_version = ""; try { PackageManager packageManager = context.getPackageManager(); PackageInfo packageInfo = packageManager.getPackageInfo(context.getPackageName(),0); now_version = packageInfo.versionName;//获取原版本号 } catch (PackageManager.NameNotFoundException e) { e.printStackTrace(); } if(new_version.equals(now_version)){ view.showError(""); Log.d("版本号是", "onResponse: "+now_version); }else{ view.showUpdateDialog(updateInfo); } } }); }

下载apk

    public void downFile(final String url) {
        Log.d("SettingPresenter", "downFile: "); model = Model.getInstance(); model.get(url,new okhttp3.Callback(){ @Override public void onFailure(Call call, IOException e) { view.downFial(); } @Override public void onResponse(Call call, Response response) throws IOException { InputStream is = null;//输入流 FileOutputStream fos = null;//输出流 try { is = response.body().byteStream();//获取输入流 long total = response.body().contentLength();//获取文件大小 view.setMax(total);//为progressDialog设置大小 if(is != null){ Log.d("SettingPresenter", "onResponse: 不为空"); File file = new File(Environment.getExternalStorageDirectory(),"Earn.apk");// 设置路径 fos = new FileOutputStream(file); byte[] buf = new byte[1024]; int ch = -1; int process = 0; while ((ch = is.read(buf)) != -1) { fos.write(buf, 0, ch); process += ch; view.downLoading(process); //这里就是关键的实时更新进度了！ } } fos.flush(); // 下载完成 if(fos != null){ fos.close(); } view.downSuccess(); } catch (Exception e) { view.downFial(); Log.d("SettingPresenter",e.toString()); } finally { try { if (is != null) is.close(); } catch (IOException e) { } try { if (fos != null) fos.close(); } catch (IOException e) { } } } //private void down() { // progressDialog.cancel(); // } }); }

View层

这一层注意的东西很多，例如Android6.0以上等需要在这里设置一下权限，还有Dialog注意关闭，否则出现窗口泄露问题。话不多说，直接上代码

public class MainActivity extends AppCompatActivity { //下载进度 private ProgressDialog progressDialog; private Button button; private SettingPresenter presenter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); presenter = new SettingPresenter(this,this); button = (Button) findViewById(R.id.button); button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (Build.VERSION.SDK_INT >= 23) {//如果是6.0以上的 int REQUEST_CODE_CONTACT = 101; String[] permissions = {Manifest.permission.WRITE_EXTERNAL_STORAGE}; //验证是否许可权限 for (String str : permissions) { if (MainActivity.this.checkSelfPermission(str) != PackageManager.PERMISSION_GRANTED) { //申请权限 MainActivity.this.requestPermissions(permissions, REQUEST_CODE_CONTACT); return; } } } presenter.updateAPK(); } }); } //显示更新错误 public void showError(final String msg) { runOnUiThread(new Runnable() { @Override public void run() { Toast.makeText(MainActivity.this, msg, Toast.LENGTH_SHORT).show(); } }); } //显示进度条 public void showUpdateDialog(final UpdateInfo updateInfo) { runOnUiThread(new Runnable() { @Override public void run() { AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this); builder.setIcon(android.R.drawable.ic_dialog_info); builder.setTitle("请升级APP至版本" + updateInfo.getVersion()); builder.setMessage(updateInfo.getDescription()); builder.setCancelable(false); builder.setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { if (Environment.getExternalStorageState().equals( Environment.MEDIA_MOUNTED)) { downFile(updateInfo.getUrl()); } else { Toast.makeText(MainActivity.this,"SD卡不可用，请插入SD卡",Toast.LENGTH_LONG).show(); } } }); builder.setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }); builder.create().show(); } }); } //下载apk操作 public void downFile(final String url) { progressDialog = new ProgressDialog(MainActivity.this); //进度条，在下载的时候实时更新进度，提高用户友好度 progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL); progressDialog.setTitle("正在下载"); progressDialog.setMessage("请稍候..."); progressDialog.setProgress(0); progressDialog.show(); presenter.downFile(url); Log.d("SettingActivity", "downFile: "); } /** * 进度条实时更新 * @param i */ public void downLoading(final int i) { runOnUiThread(new Runnable() { @Override public void run() { progressDialog.setProgress(i); } }); } /** * 下载成功 */ public void downSuccess() { runOnUiThread(new Runnable() { @Override public void run() { if (progressDialog != null && progressDialog.isShowing()) { progressDialog.dismiss(); } AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this); builder.setIcon(android.R.drawable.ic_dialog_info); builder.setTitle("下载完成"); builder.setMessage("是否安装"); builder.setCancelable(false); builder.setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { Intent intent = new Intent(Intent.ACTION_VIEW); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { //aandroid N的权限问题 intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION); Uri contentUri = FileProvider.getUriForFile(MainActivity.this, "对应的包名.fileprovider", new File(Environment.getExternalStorageDirectory(), "软件名.apk"));//注意修改 intent.setDataAndType(contentUri, "application/vnd.android.package-archive"); } else { intent.setDataAndType(Uri.fromFile(new File(Environment.getExternalStorageDirectory(), "软件名.apk")), "application/vnd.android.package-archive"); intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); } startActivity(intent); } }); builder.setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }); builder.create().show(); } }); } /** * 下载失败 */ public void downFial() { runOnUiThread(new Runnable() { @Override public void run() { progressDialog.cancel(); Toast.makeText(MainActivity.this,"更新失败",Toast.LENGTH_LONG).show(); } }); } public void setMax(final long total) { runOnUiThread(new Runnable() { @Override public void run() { progressDialog.setMax((int) total); } }); } }

注意：在跳转到安装界面时，android 6.0即android N以上的需要设置权限。

首先在Manifests加上

  <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="对应的包名.fileprovider" android:grantUriPermissions="true" android:exported="false" > <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/file_paths" /> </provider>

然后在res中创建xml包，存放file_paths.xml文件

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <external-path path="Android/data/com.earn/" name="files_root" /> <external-path path="." name="external_storage_root" /> </paths>

文章所用Demo这里下载