从Java中的构造函数中具有数组参数的类实例化

Question

I have looked at several posts to reach an answer, but none came close enough.

I have a Q that might sound very empirical, and I am sure the answer is staring me in the face, but I am blinkered, I suppose! I have a class named DrugExcretion with a constructor that has a parameter that is a reference to an array (named drugExcretionCode).

I can't seem to work out the SYNTAX to instantiate (ie create an object) in my main class named DrugExcretionApp. Both classes are below:-

If anyone can direct me to a simple way to do this, it would be much appreciated. Thanks in advance.

public class DrugExcretion implements CautionInterface{

    int[] drugExcretionCode;
    private String[] drug;

    public DrugExcretion(String[] drug){
        this.drug = drug;
    }

    public String determineDanger(int[] drugExcretionCode){

    String site1 = "kidney";
    String site2 = "liver";
    String site;
    if (drugExcretionCode = 1){
        return "reduce dosage in elderly";
    }
    else{

        return "reduce dosage in children";
        }

}
}

x ----------------- o ----------------- x ----------------- o

public class drugExcretionApp {

public static void main(String[] args) {

        // TODO Auto-generated method stub

        final String drug1 = "enalapril";
        final String drug2 = "captopril";
        final String drug3 = "metoprolol";
        final String drug4 = "amlodipine";
        final String drug5 = "candesartan";

        String drug[] = {drug1, drug2, drug3, drug4, drug5};
        DrugExcretion listOne = new DrugExcretion(drug);


        DrugExcretion.determineDanger(new int[]{1, 1, 2, 2, 1});
        }

}

I get an error "DrugExcretion cannot be resolved to a type" which initially made me think that the project setup was incorrect so the DrugExcretion class could not be seen by the app class - I rearranged the classes to keep them in the same package, but the error persists.

It appears to be a problem with access modifiers - have I made something static inadvertently???

BTW, the interface simply contains a signature of the only method in the first class.

Answer 1

You have to call determineDanger like this:

listOne.determineDanger(new int[]{1, 1, 2, 2, 1]);

DrugExcretion.xxx would be for a static method xxx of DrugExcretion . But determineDanger is an instance method, so needs to be invoked on an instance of the class, in this case listOne .

Answer 2

Since you are instantiating the DrugExcretion class, you need to call

listOne.determineDanger(new int[] { 1, 1, 2, 2, 1 });

Also, please check your code in the DrugExcretion class. It should be equals operator and not assignment.

if (drugExcretionCode == 1){