通过okhttp3下载文件实现APP版本更新

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。

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



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());<
4000
/span>
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