Converting arrays to linked lists en masse

I’m currently writing a JUnit test that requires a Tree Map as an expected value.

Said TreeMap looks like this:

Map<Integer, LinkedList<String>> expected = new TreeMap<>();

I filled said Tree Map with the data that should return from the Test:

    expected.put(1, (LinkedList<String>) Arrays.asList("18_2_2_3_java.lang.String_", "27_0_0_93_java.sql.Timestamp_", "256_6_6_0_java.lang.String_", "200_6_6_12_java.lang.String_", "8_0_0_12_java.lang.String_", "4_2_2_5_java.lang.Integer_", "5_6_6_5_java.lang.Short_", "23_0_0_93_java.util.Date_", "5_0_0_5_java.lang.Integer_", "35_0_0_12_java.lang.String_", "20_6_6_0_java.lang.String_", "19_0_0_12_java.util.Date_", "12_6_6_12_java.lang.String_", "112_0_0_12_java.lang.String_", "1_0_0_5_java.lang.Short_", "4_0_0_2_java.lang.String_", "7_6_6_12_java.lang.String_", "3_0_0_5_java.lang.Integer_", "0_6_6_5_java.lang.Boolean_", "-1_0_0_2005_byte[]_", "19_6_6_1_java.lang.String_", "3_0_0_4_java.lang.String_", "4365_6_6_93_java.sql.Timestamp_", "0_6_6_5_java.lang.Integer_", "23_6_6_93_java.sql.Timestamp_", "1_250_250_12_java.lang.String_"));
    expected.put(2, (LinkedList<String>) Arrays.asList("2_6_6_12_java.lang.String_", "-1_6_6_2005_java.lang.String_", "20_0_0_12_java.lang.Long_", "25_0_0_12_java.lang.String_", "2_6_6_5_java.lang.Integer_", "500_0_0_12_java.lang.String_", "5_6_6_5_java.lang.Boolean_", "128_6_6_0_java.lang.String_", "512_6_6_12_java.lang.String_", "6_2_2_3_java.math.BigDecimal_", "25_6_6_12_java.lang.String_", "4_6_6_12_java.lang.String_", "19_6_6_0_java.lang.String_", "12_0_0_12_java.lang.String_", "1_6_6_5_java.lang.Boolean_", "2_0_0_5_java.lang.Short_", "50_6_6_12_java.lang.String_", "0_6_6_0_java.lang.Boolean_", "0_0_0_5_java.lang.Boolean_", "-1_6_6_-1_java.lang.String_", "4_0_0_12_java.lang.String_", "10_0_0_4_java.lang.Boolean_", "80_0_0_12_java.lang.String_", "20_8_8_3_java.math.BigDecimal_", "18_3_3_3_java.math.BigDecimal_"));
    expected.put(3, (LinkedList<String>) Arrays.asList("150_0_0_12_java.lang.String_", "0_6_6_0_java.sql.Timestamp_", "0_6_6_0_java.lang.Integer_", "1_0_0_5_java.lang.Boolean_", "32_6_6_12_java.lang.String_", "4_0_0_93_java.sql.Timestamp_", "2_0_0_12_java.lang.String_", "0_6_6_91_java.util.Date_"));
    expected.put(4, (LinkedList<String>) Arrays.asList("1024_6_6_1_java.lang.String_", "-1_6_6_-4_byte[]_", "30_6_6_12_java.lang.String_", "27_6_6_93_java.sql.Timestamp_", "40_0_0_12_java.lang.String_", "2_6_6_5_java.lang.String_", "2_2_2_5_java.lang.Short_", "2_0_0_4_java.lang.Integer_", "2000_6_6_12_java.lang.String_", "120_6_6_12_java.lang.String_", "4365_6_6_93_java.util.Date_", "256_6_6_12_java.lang.String_"));
//There is a lot more but you get the point

As some of you maybe already have noticed; the Lists are wrong.
They have to be Linked Lists.

Eclipse recommended Type Casting the List to a Linked List which is what I tried, but that didn’t work out.

I’m pretty lost on this one.

>Solution :

lance-java’s suggestions would work, but they are quite cumbersome.

I would suggest defining a method like this:

public static LinkedList<String> linkedList(String... values) {
  return new LinkedList<>(List.of(values));
}

and then invoke this in your test:

expected.put(1, linkedList("18_2_2_3_java.lang.String_", "27_0_0_93_java.sql.Timestamp_" /* etc */);
// etc

It’s just a bit neater.