Why ArrayList<String> get() returns Object not String in Java

Question

While making an argument parser, I used ArrayList<String>.
Refering to this official Documentation, ArrayList<E>.get() should be returning E typed Objects, so ArrayList<String>.get() should be returning String Objects.

However, I am getting Object instead of String elements in this case.

import lombok.Data;

import java.util.ArrayList;

@Data
public class Argument<T> {
    public ArrayList<String> Args;
    public String Description;
    public Boolean Required;
    public Boolean HasValue;
    public T Value;
}

import org.jetbrains.annotations.NotNull;

import java.util.ArrayList;

public class ArgumentParser {
    private ArrayList<Argument> argumentList_;

    public String ArgList() {
        StringBuilder builder = new StringBuilder(); 
        for (Argument argument : argumentList_) {

            //Here is the problem
            for (String arg : argument.Args) {
                builder.append(arg);
                builder.append(", ");
            }
        }
        //Delete Traling Comma
        builder.delete(builder.length());
        builder.delete(builder.length());

        return builder.toString();
    }
}

Is this situation

1. A bug in IDE Environment (IntelliJ + Lombok)
2. My code is making Java do this (Generic Typing)

Help me...

Answer 1

In the first piece of code Argument is defined to have a type parameter.

public class Argument<T> {
    public ArrayList<String> Args;

In the second piece of code Argument is used but the type argument is missing.

    private ArrayList<Argument> argumentList_;
    // ...
        for (Argument argument : argumentList_) {

ArrayList<Argument> is a rare type (less frequently(?) known as a partial raw type - a type with a raw type argument). The behaviour of which is odd.

The easy fix is a wildcard.

    private ArrayList<Argument<?>> argumentList_;
    // ...
        for (Argument<?> argument : argumentList_) {