Pass a constructor argument to a static block

I have a class like this

public class CustomRestClient {

private static String dbString;

public CustomRestClient(String db) {
    this.dbString = db;
}

static {       
    try {
        Client.setServer(Client.Server.LOCAL);
        AuthenticationProvider provider = new AuthenticationProvider();
        provider.setCredentialsProvider(new SimpleCredentialsProvider("user", "pass", dbString, "secretkey"));
        Client.setAuthenticationProvider(provider);
        Client.login();
    } catch (ClientException e) {
        e.printStackTrace();
    }
}

public static void main(String[] args) {
    CustomRestClient customRestClient = new CustomRestClient("db");
 }
}

I'm trying to pass the constructor argument inside the static block

provider.setCredentialsProvider(new SimpleCredentialsProvider("user", "pass", dbString, "secretkey"));

For example, CustomRestClient customRestClient = new CustomRestClient("db"); should set the dbString field inside the static block to db. But when I run the program it says the dbString field is null. I have no idea what I'm doing wrong

static block is executed before you create the CustomRestClient object

You should move the static block to static method and call it

public static void login(String db) {
        Client.setServer(Client.Server.LOCAL);
        AuthenticationProvider provider = new AuthenticationProvider();
        provider.setCredentialsProvider(new SimpleCredentialsProvider("user", "pass", dbString, "secretkey"));
        Client.setAuthenticationProvider(provider);
        Client.login();
}

And call it:

CustomRestClient.login("db")

Or (without static) move the method inside a constructor with String argument

private String dbString;

public CustomRestClient(String db) {
    this.dbString = db;
    try {
        Client.setServer(Client.Server.LOCAL);
        AuthenticationProvider provider = new AuthenticationProvider();
        provider.setCredentialsProvider(new SimpleCredentialsProvider("user", "pass", dbString, "secretkey"));
        Client.setAuthenticationProvider(provider);
        Client.login();
    } catch (ClientException e) {
        e.printStackTrace();
    }

}