安卓APP自动更新功能实现

前言

安卓App自动更新基本上是每个App都需要具备的功能，接下来介绍一下实现自动更新的步骤。

代码实现

App自动更新主要分为新版本检测、升级弹窗、下载升级包、安装app这4个步骤，以下为MainActivity的实现代码（注意：目标升级版本和升级包下载地址实际需要向平台拉取）：

package com.example.testupgrade;

import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.FileProvider;

import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

import java.io.File;

public class MainActivity extends AppCompatActivity {

    private final String TAG = "Jason";
    private File file;

    private TextView textView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initView();

        if(versionCheck()) {
            showTip(this);
        }
    }

	//在主界面显示app版本号，非必要
    private void initView() {
        textView = findViewById(R.id.tv_version);
        textView.setText("version:" + getVersionName());
    }

    //新版本检测
    private boolean versionCheck() {
        String targetVersion = "xxx"; //todo 实际目标版本号应向平台查询

        Log.d(TAG, "versionCheck version:" + getVersionName());
        Log.d(TAG, "versionCheck targetVersion:" + targetVersion);
        if(getVersionName().contentEquals(targetVersion)) {
            return false;
        } else {
            return true;
        }
    }

    //升级弹窗
    private void showTip(Context context) {
        AlertDialog dialog = new AlertDialog.Builder(context).setTitle("升级提示").setMessage("检测到新版本，请升级")
            .setNeutralButton("升级", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    doDownload();
                }
            }).setNegativeButton("取消", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.dismiss();
                }
            }).show();
        dialog.setCanceledOnTouchOutside(false);//可选
        dialog.setCancelable(false);//可选
    }

    //下载升级包
    private void doDownload() {

        String downloadUrl = "https://xxx"; //todo 实际下载地址应向平台查询

        String parentPath = "";
        try {
            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
                parentPath = this.getExternalFilesDir(null).getPath();
            } else {
                parentPath = this.getFilesDir().getPath();
            }
        } catch (Exception e) {
            Log.d(TAG, "doDownload e:" + e.getMessage());
        }

        Log.d(TAG, "doDownload parentPath:" + parentPath);
        file = new File(parentPath, "myhouse.apk");
        final String filePath = file.getAbsolutePath();

        //如果已有文件，删除
        if (file.exists()) {
            Log.d(TAG, "doDownload delete APK");
            file.delete();
        }

        try {
            DownloadUtil.get().download(downloadUrl, filePath, new DownloadUtil.OnDownloadListener() {
                @Override
                public void onDownloadSuccess() {
                    //成功
                    Log.d(TAG, "doDownload download success");
                    installApk();
                }

                @Override
                public void onDownloading(int progress) {
                    //进度
                    //Log.d(TAG, "doDownload download:" + progress +"%");
                }

                @Override
                public void onDownloadFailed() {
                    //失败
                    Log.d(TAG, "doDownload download fail");
                }
            });
        } catch (Exception e) {
            Log.d(TAG, "doDownload e2:" + e.getMessage());
        }
    }

    //安装app
    private void installApk() {
        Intent intent = new Intent(Intent.ACTION_VIEW);
        Uri data;

		//7.0以上安卓系统安装app需要通过fileProvider（需要在AndroidManifest.xml声明）
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            data = FileProvider.getUriForFile(this, "com.example.testupgrade.provider", file);
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
            Log.d(TAG,"installApk 7.0data:" + data);
        } else {
            data = Uri.fromFile(file);
            Log.d(TAG,"installApk data:" + data);
        }

        intent.setDataAndType(data, "application/vnd.android.package-archive");
        this.startActivity(intent);
    }

    //获取软件版本号
    private String getVersionName() {
        String versionName = "";
        try {
            versionName = getApplicationContext().getPackageManager().getPackageInfo(getApplicationContext().getPackageName(), 0).versionName;
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return versionName;
    }
}

上述下载功能基于okhttp实现的DownloadUtil工具类，具体代码如下：

package com.example.testupgrade;

import android.os.Environment;
import android.util.Log;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class DownloadUtil {
    private static DownloadUtil downloadUtil;
    private final OkHttpClient okHttpClient;

    public static DownloadUtil get() {
        if (downloadUtil == null) {
            Log.d("Jason", "DownloadUtil get new DownloadUtil");
            downloadUtil = new DownloadUtil();
        }
        return downloadUtil;
    }

    private DownloadUtil() {
        okHttpClient = new OkHttpClient();
    }

    /**
     * @param url 下载连接
     * @param filePath 储存下载文件的SDCard目录
     * @param listener 下载监听
     */
    public void download(final String url, final String filePath, final OnDownloadListener listener) {
        Log.d("Jason", "DownloadUtil download start");
        Request request = new Request.Builder().url(url).build();
        Log.d("Jason", "DownloadUtil request:" + request.toString());
        okHttpClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                Log.d("Jason", "DownloadUtil onFailure e:" + e.getMessage());
                listener.onDownloadFailed();
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                Log.d("Jason", "DownloadUtil onResponse start");
                InputStream is = null;
                byte[] buf = new byte[2048];
                int len = 0;
                FileOutputStream fos = null;
                // 储存下载文件的目录
                //String savePath = isExistDir(saveDir);
                Log.d("Jason", "DownloadUtil filePath:" + filePath);
                try {
                    is = response.body().byteStream();
                    long total = response.body().contentLength();
                    //File file = new File(savePath, getNameFromUrl(url));
                    File file = new File(filePath);
                    fos = new FileOutputStream(file);
                    long sum = 0;
                    while ((len = is.read(buf)) != -1) {
                        fos.write(buf, 0, len);
                        sum += len;
                        int progress = (int) (sum * 1.0f / total * 100);
                        // 下载中
                        listener.onDownloading(progress);
                    }
                    fos.flush();
                    // 下载完成
                    listener.onDownloadSuccess();
                } catch (Exception e) {
                    Log.d("Jason", "DownloadUtil onResponse e1:" + e.getMessage());
                    listener.onDownloadFailed();
                } finally {
                    try {
                        if (is != null) {
                            is.close();
                        }
                    } catch (IOException e) {
                        Log.d("Jason", "DownloadUtil onResponse e2:" + e.getMessage());
                    }
                    try {
                        if (fos != null) {
                            fos.close();
                        }
                    } catch (IOException e) {
                        Log.d("Jason", "DownloadUtil onResponse e3:" + e.getMessage());
                    }
                }
            }

        });
    }

    /**
     * @param saveDir
     * @return
     * @throws IOException
     * 判断下载目录是否存在
     */
    private String isExistDir(String saveDir) throws IOException {
        // 下载位置
        File downloadFile = new File(Environment.getExternalStorageDirectory(), saveDir);
        if (!downloadFile.mkdirs()) {
            downloadFile.createNewFile();
        }
        String savePath = downloadFile.getAbsolutePath();
        return savePath;
    }

    /**
     * @param url
     * @return
     * 从下载连接中解析出文件名
     */
    public static String getNameFromUrl(String url) {
        return url.substring(url.lastIndexOf("/") + 1);
    }

    public interface OnDownloadListener {
        /**
         * 下载成功
         */
        void onDownloadSuccess();

        /**
         * @param progress
         * 下载进度
         */
        void onDownloading(int progress);

        /**
         * 下载失败
         */
        void onDownloadFailed();
    }
}

注：为了使用okhttp，需要在build.gradle添加如下配置：

implementation 'com.squareup.okhttp3:okhttp:4.3.1'

为了实现下载和安装功能，需要在AndroidManifest.xml声明网络、SD卡读写和安装包权限；另外，为了实现7.0以上安卓系统的app安装，还需要声明fileProvider，具体代码如下：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.testupgrade">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES"/>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:networkSecurityConfig="@xml/network_security_config"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <provider
            android:name="androidx.core.content.FileProvider"
            android:authorities="${applicationId}.provider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/file_path" />
        </provider>
    </application>

</manifest>

添加fileProvider对应的file_path.xml

<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:android="http://schemas.android.com/apk/res/android">
    <paths>
        <external-path path="" name="download"/>
    </paths>
</resources>

添加network_security_config.xml，配置可访问http地址：

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true" />
</network-security-config>