Question

If I start with a method like this:

package com.sandbox;

import java.util.ArrayList;
import java.util.List;

public class Sandbox {

    public static void main(String[] args) {
        List<String> strings = new ArrayList<String>();
        strings.add("a");
        strings.add("b");

        for (String string : strings) {
            System.out.println(string);
        }
    }
}

If I highlight the first add(...) line and then extract method, the code turns into this:

package com.sandbox;

import java.util.ArrayList;
import java.util.List;

public class Sandbox {

    public static void main(String[] args) {
        List<String> strings = new ArrayList<String>();
        addA(strings);
        strings.add("b");

        for (String string : strings) {
            System.out.println(string);
        }
    }

    private static void addA(List<String> strings) {
        strings.add("a");
    }
}

I almost never want this. I’d rather it do something like this:

package com.sandbox;

import java.util.ArrayList;
import java.util.List;

public class Sandbox {

    public static void main(String[] args) {
        List<String> strings = new ArrayList<String>();
        strings.addAll(addA());
        strings.add("b");

        for (String string : strings) {
            System.out.println(string);
        }
    }

    private static List<String> addA() {
        List<String> strings = new ArrayList<String>();
        strings.add("a");
        return strings;
    }
}

Or maybe something like this:

package com.sandbox;

import java.util.ArrayList;
import java.util.List;

public class Sandbox {

    public static void main(String[] args) {
        List<String> strings = addA();        
        strings.add("b");

        for (String string : strings) {
            System.out.println(string);
        }
    }

    private static List<String> addA() {
        List<String> strings = new ArrayList<String>();
        strings.add("a");
        return strings;
    }
}

Is there a way to make intellij extract methods this way?

Answer 1

You could get the second result by selecting the first two lines of the method (including the new ArrayList call).