【Android】java中如何判断设备是否在root状态

前言

客户需求，需要判断设备是否执在root状态。可以理解为是否执行了adb root 设置root状态，已经adb unroot设置unroot状态。

代码分析

分析adb deamon发现：在执行adb root 、adb unroot指令时，系统会更新service.adb.root 变量。

void restart_root_service(unique_fd fd) {
    if (getuid() == 0) {
        WriteFdExactly(fd.get(), "adbd is already running as root\n");
        return;
    }
    if (!__android_log_is_debuggable()) {
        WriteFdExactly(fd.get(), "adbd cannot run as root in production builds\n");
        return;
    }

    LOG(INFO) << "adbd restarting as root";
    android::base::SetProperty("service.adb.root", "1");
    WriteFdExactly(fd.get(), "restarting adbd as root\n");
}

void restart_unroot_service(unique_fd fd) {
    if (getuid() != 0) {
        WriteFdExactly(fd.get(), "adbd not running as root\n");
        return;
    }

    LOG(INFO) << "adbd restarting as nonroot";
    android::base::SetProperty("service.adb.root", "0");
    WriteFdExactly(fd.get(), "restarting adbd as non root\n");
}

实现

系统应用可以通过SystemProperties get "service.adb.root" value来判断是否root。

public static final String ADB_ROOT_PROP = "service.adb.root";

public static boolean deviceIsRooted(){
return SystemProperties.getInt(ADB_ROOT_PROP,0) == 1 ? true:false;
}