Modify String object value passed as parameter

Question

I need to change the value of a variable dynamically by passing it as a parameter by an auxiliary method. I have always used the values of the parameters by moving from right to left. It is possible to change the variable from left to right:

Fields of my class:

private String ipAddress;
private String dnsAddress;

Set method to assign value to variable:

public void setDHCP(){        
    cmdAdress(ipAddress,"address", "dhcp");
    cmdAdress(dnsAddress, "dnsservers", "dhcp");        
}

Auxiliary method to make set dynamic:

private void cmdAdress(String address, String type, String adresses){          
    //Isso não funciona
    address = "netsh interface ip set ";

    //Isso funciona mas não me é útil
    //ipAddress = "netsh interface ip set ";

    //restante do código
    address += type;        
    address += " name = \"" + adapterName + "\" ";      
    address += adresses + " "; 
}

The expected value would be something like this:

ipAddress: netsh interface ip set address name = \"OffBoard\" static 192.168.1.220 255.255.255.0 192.168.1.1
dnsAddress: netsh interface ip set dnsservers name=\"OffBoard\" static 192.168.1.1 primary no

Although you get no error, the value of the fields are always empty. I am doing something wrong or demanding something that is not the language?

Answer 1

I think it would be better to use function return to define the ipAddress and the dnsAddress. Leaves the passage by parameter only to input the necessary data to the function. According to your example, it would look like this:

final private String TIPO_ADDRESS = "address";
final private String TIPO_DNSSERVERS = "dnsservers";
private String ipAddress;
private String dnsAddress;

public void setDHCP(){        
    ipAddress = cmdAdress(TIPO_ADDRESS, "dhcp");
    dnsAddress = cmdAdress(TIPO_DNSSERVERS, "dhcp");        
}

private String cmdAdress(String type, String adresses){
    String retorno = "netsh interface ip set ";
    retorno += type;
    retorno += " name = \"" + adapterName + "\" ";
    //Não sei de onde viria o adapterName - talvez de uma variável global, mas não é aconselhável - que tal passar como parâmetro também?
    //Se for uma constante, padronize o nome como maiúscula, igual ao TIPO_ADDRESS E TIPO_DNSSERVERS
    retorno += adresses + " ";
    return retorno;
}