java - How to store more than one value for same key in HashMap? -

i have string named inputrow, looks this:

1,kit,23 2,ret,211 

i apply regex (.+),(.+),(.+) on , store results in multiple variables.

for first line 1,kit,23 get:

inputrow.1-->1 inputrow.2-->kit inputrow.3-->23 

for second line 2,ret,211 get:

inputrow.1-->2 inputrow.2-->ret inputrow.3-->211 

i want store input rows in hashmap same key inputrow. how can in java?

my java code is..,

line="1,kit,23"; final map<string, string> regexresults = new hashmap<>(); pattern pattern = pattern.compile("(.+),(.+),(.+)"); final matcher matcher = pattern.matcher(line); if (matcher.find())  { final string basekey = "inputrow"; (int = 0; <= matcher.groupcount(); i++) { final string key = new stringbuilder(basekey).append(".").append(i).tostring();  string value = matcher.group(i); if (value != null) {    regexresults.put(key, value); } } 

now wants store second row in "regexresults" process.how possible?

create class inputrow:

class inputrow {      private int value1;     private string value2;     private int value3;      //...getters , setters  } 

and hashmap<integer, list<inputrow>>. hash map key row index , assign matching rows list<inputrow> hash map.

for clarification, hashmap stores one entry one unique key. therefore, cannot assign more 1 entry same key or else entry overwritten. so, need write container cover multiple objects or use existing list.

example code

i used both of text fragments, separated newline character, 2 lines. snippet puts 2 inputrow objects in list hashmap key "inputrow". note, matcher group index starts @ 1, 0 refers whole group. mind simplicity assumed created inputrow(string, string, string) constructor.

string line = "1,kit,23\n2,ret,211";  final map<string, list<inputrow>> regexresults = new hashmap<>(); pattern pattern = pattern.compile("(.+),(.+),(.+)"); final matcher matcher = pattern.matcher(line);  list<inputrow> entry = new arraylist<>();  while (matcher.find()) {     entry.add(new inputrow(matcher.group(1), matcher.group(2), matcher.group(3))); }  regexresults.put("inputrow", entry);