Method FindJavaFromRegistryKey

launcher/java/JavaUtils.cpp:153–232

#if defined(Q_OS_WIN32)
QList<JavaInstallPtr> JavaUtils::FindJavaFromRegistryKey(DWORD keyType, QString keyName, QString keyJavaDir, QString subkeySuffix)
{
    QList<JavaInstallPtr> javas;

    QString archType = "unknown";
    if (keyType == KEY_WOW64_64KEY)
        archType = "64";
    else if (keyType == KEY_WOW64_32KEY)
        archType = "32";

    HKEY jreKey;
    if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, keyName.toStdString().c_str(), 0,
                      KEY_READ | keyType | KEY_ENUMERATE_SUB_KEYS, &jreKey) == ERROR_SUCCESS)
    {
        // Read the current type version from the registry.
        // This will be used to find any key that contains the JavaHome value.
        char *value = new char[0];
        DWORD valueSz = 0;
        if (RegQueryValueExA(jreKey, "CurrentVersion", NULL, NULL, (BYTE *)value, &valueSz) ==
            ERROR_MORE_DATA)
        {
            value = new char[valueSz];
            RegQueryValueExA(jreKey, "CurrentVersion", NULL, NULL, (BYTE *)value, &valueSz);
        }

        TCHAR subKeyName[255];
        DWORD subKeyNameSize, numSubKeys, retCode;

        // Get the number of subkeys
        RegQueryInfoKey(jreKey, NULL, NULL, NULL, &numSubKeys, NULL, NULL, NULL, NULL, NULL,
                        NULL, NULL);

        // Iterate until RegEnumKeyEx fails
        if (numSubKeys > 0)
        {
            for (DWORD i = 0; i < numSubKeys; i++)
            {
                subKeyNameSize = 255;
                retCode = RegEnumKeyEx(jreKey, i, subKeyName, &subKeyNameSize, NULL, NULL, NULL,
                                       NULL);
                if (retCode == ERROR_SUCCESS)
                {
                    // Now open the registry key for the version that we just got.
                    QString newKeyName = keyName + "\\" + subKeyName + subkeySuffix;

                    HKEY newKey;
                    if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, newKeyName.toStdString().c_str(), 0,
                                     KEY_READ | KEY_WOW64_64KEY, &newKey) == ERROR_SUCCESS)
                    {
                        // Read the JavaHome value to find where Java is installed.
                        value = new char[0];
                        valueSz = 0;
                        if (RegQueryValueEx(newKey, keyJavaDir.toStdString().c_str(), NULL, NULL, (BYTE *)value,
                                            &valueSz) == ERROR_MORE_DATA)
                        {
                            value = new char[valueSz];
                            RegQueryValueEx(newKey, keyJavaDir.toStdString().c_str(), NULL, NULL, (BYTE *)value,
                                            &valueSz);