Question

I’m trying to find and read a string from a text file using a “.equal” in java. I know that I can simply do this by using “.contain” instead, but I just want to know if there is anyway to find and read the line like this:

For example I have the following data in the text file:

ID1   123   123
ID2   125   136

Now

String ID="ID1"; 
while ((ss = buffered_reader.readLine()) != null){
if (ss.equals(ID+[anything])){do something} } 

Why I want to this is to prevent getting result for entering just “ID”. So is there any way like a regex or something that can help ?

Clarification :

I want to find the exact match for the ID , for example :

if you enter ID1 then the program says : true
but false for entering just ID

if I use .contain the program finds the word ID1 or ID2 and because they contain “ID” , then it always returns a true value.

now I want to use .eqaual to find the exact match followed by anything

Answer 1

Try this:

String ID="ID1"; 
while ((ss = buffered_reader.readLine()) != null) {
    if (ss.matches(ID+".*")){do something} }
}

The expresion .* means any sequence of characters, even an empty sequence. So if ID is “ID1” then it will match any string that begins with ID1.