在应用程序中使用以下代码示例来检查Play完整性：

private boolean isPlayStoreInstalled() {
    PackageManager pm = getPackageManager();
    try {
        pm.getPackageInfo("com.android.vending", PackageManager.GET_ACTIVITIES);
        return true;
    } catch (PackageManager.NameNotFoundException e) {
        return false;
    }
}

private boolean isPlayStoreCertified() {
    GoogleApiAvailability gaa = GoogleApiAvailability.getInstance();
    int status = gaa.isGooglePlayServicesAvailable(this);
    if (status == ConnectionResult.SUCCESS) {
        return true;
    } else {
        return false;
    }
}

private boolean isAppVerificationEnabled() {
    ContentResolver cr = getContentResolver();
    int enabled = Settings.Secure.getInt(cr, Settings.Secure.APP_VERIFICATION_ENABLED, 1);
    if (enabled > 0) {
        return true;
    } else {
        return false;
    }
}

private void checkPlayIntegrity() {
    boolean isPlayStoreInstalled = isPlayStoreInstalled();
    boolean isPlayStoreCertified = isPlayStoreCertified();
    boolean isAppVerificationEnabled = isAppVerificationEnabled();

    if (!isPlayStoreInstalled || !isPlayStoreCertified || !isAppVerificationEnabled) {
        // Play integrity check failed, handle this error
    }
}

这段代码将检查三个条件：

1. 是否已在设备上安装了Play商店
2. 当前是否已完成Play商店的验证
3. 应用程序验证是否已启用

如果三个条件都成立，则可以认为该应用程序在Play上具有完整性。当其中任何一个条件无法满足时，则可能存在安全问题，应该根据实际需求进行适当的处理。