Build a List from a String

Question

I am trying to make a generic function that builds a List of any type based on a string that holds values of that type delimited by let's say a comma. I have done this:

public static <T> List<T> stringToList(String listStr, Class<T> itemType)
{
    return Arrays.asList(listStr.split(",")).stream().map(x -> itemType.cast(x.replaceAll("\\s+|\"|\t","")))).collect(Collectors.toList());
}

When I try to test it with:

String listStringsStr  = "\"Foo\", \"Bar\"";
List<String> resS = stringToList(listStringsStr, String.class);

String listIntegersStr = "1,10,-1,0";
List<Integer> resI = stringToList(listStringsStr, Integer.class);

I have two problems.

1. In the first case (String) I get an extra double quote around each string item: ""Foo"", ""Bar"".
2. In the second case (Integer) I get a java.lang.ClassCastException: Cannot cast java.lang.String to java.lang.Integer which means that it can't convert "1" to 1. I know this works with Integer::parseInt, but I want to make a generic method.

Any Ideas?

[EDIT] - Because I caused confusion the way I posted it, I add the test code:

String listStringsStr  = "\"Foo\", \"Bar\"";
List<String> listStrings = Arrays.asList("Foo", "Bar");
String listIntegersStr = "1,10,-1,0";
List<Integer> listIntegers = Arrays.asList(1, 10, -1, 0);

List<String> resS = stringToList(listStringsStr, String.class);
System.out.println(resS);
System.out.println(listStrings);
assert (resS.containsAll(listStrings));

List<Integer> resI = stringToList(listIntegersStr, Integer.class);
System.out.println(resI);
System.out.println(listIntegers);
assert (resI.containsAll(listIntegers));

After including the x.replaceAll("\\s+|\"|\t","") the first assertion now pass, the second fails. The console output is

[Foo, Bar]
[Foo, Bar]
[1, 10, -1, 0]
[1, 10, -1, 0]

listIntegers holds Integer thus I suppose resI holds ints, or I just broke java's type safety :D

Answer 1

For problem #2: A simple modification would be to pass a Function<String, T> instead of Class<T>. The function would define how to parse the string as the class of the desired type. Some possible values:

Function<String, String> stringParser = s -> s;
Function<String, Integer> intParser = s -> Integer.parseInt(s);

For problem #1: In the example you gave the input strings do contain quotes. You could have made the input string "Foo,Bar" to avoid having quotes in the output. If you don't have control over the input, you can trim quotes/whitespace/etc. as part of the parsing function, or separate the words by something more advanced than splitting by commas - is the input a CSV file?