Comparing two sentences

Question

Hello all,
I have a text file in the following format it has two lines
Shop_Evaporator_Item1     Shop_EvaGap_Item1     Shop_Housing_Item1     Shop_EvaPort_Item1     
Evaporator     EvaGap     Housing     My aim is to truncate the first line in such a way that , all the items in the first line only contain the word between the first and second underscore "_" .
In short I want to make the first line like the second line, since the strings in the second line are substrings of the items in the first line.
my output should be
Evaporator     EvaGap     Housing     Evaport 
Evaporator     EvaGap     HousingThese sentences are sorted.
I guess i cannot use substring method , since i need to specify the index, I would like to do it without using the index and by using the delimiter.
Any ideas on how I should proceed.

Answer 1

Thank you all for the great replies. all the codes given by the brilliant responders work, but I have another issue though :( ,
if i have a larger input say if an item is like below
Shop_Evaporator_Gap_Cube_1The regex
String regex = "\\w+_(\\w+)_\\w+";returns Cube as the result and
String regex = "((?<=(^|\t))[^\t_]+_)|(_[^\t_]+(?=(\t|$)))"; returns Evaporator_Item1_1 as the result
but the desired result is Evaporator basically the first occurence of the pattern, since the interest is only on the string after the first underscore.
if my understanding is correct, i find that the regex searches for one or more occurences with the quantifier +. so it finds the occurence of the pattern at the end of the word, but not at the beginning .
I am a total newbie to java and to regex, my understanding from what i read is that i need to make these regex to search only at the beginning and not at the end or in other words the first occurence .
The code by tschodot
public class Try2 {
    public static void main(String[] args) {
        String input =
                "Shop_Evaporator_Item1_cube_1    " +
                "Shop_EvaGap_Item1_1  " +
                "Shop_Housing_Item1 " +
                "Shop_EvaPort_Item1 ";
        String regex = "\\w+_(\\w+)_\\w+";
        String output = input.replaceAll(regex, "$1");
        System.out.println(output);
}returns
cube    Item1  Housing EvaPort also i don't understand why the code doesn't work when there is not "tab" after each string. :(
could somebody please explain. :)
Thanks in advance.