一、在AndroidManifest.xml添加权限

<uses-permission android:name="android.permission.INSTALL_PACKAGES" />

二、在AndroidManifest.xml设置程序安装在内存中

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

三、下载安装包，执行安装和重启命令

// 安装命令
val installCommand ="LD_LIBRARY_PATH=/vendor/lib*:/system/lib* pm install -r " +"下载后安装包文件的路径，例如：\sd\download\file.apk"
// 重启命令
val restartCommand ="LD_LIBRARY_PATH=/vendor/lib*:/system/lib* am start -n " + packageName + "/" + "启动页的类名称，例如：SplashActivity::class.java.canonicalName"
// 数组
val commands = arrayOf(installCommand, restartCommand)
// 执行命令
val commandResult = ShellUtils.execCmd(commands, true, true)

四、监听安装包替换的广播

public class BootBroadcastReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (action.equals("android.intent.action.PACKAGE_REPLACED")) {
            String packageName = intent.getData().getSchemeSpecificPart();
            if (context.getPackageName().equals(packageName)) {
                // 获取默认启动activity
                Intent launchIntent = context.getPackageManager().getLaunchIntentForPackage(packageName);
                launchIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                context.startActivity(launchIntent);
            }
        }
    }
}

五、注册第四步的广播

        <receiver android:name=".broadcast.BootBroadcastReceiver">
            <intent-filter>
                <action android:name="android.intent.action.PACKAGE_ADDED" />
                <action android:name="android.intent.action.PACKAGE_REPLACED" />
                <action android:name="android.intent.action.PACKAGE_REMOVED" />

                <data android:scheme="package" />
            </intent-filter>
        </receiver>