regex - Java String tokens -

i have string line

string user_name = "id=123 user=aron name=aron app=application"; 

and have list contains: {user,cuser,suser}

and have user part string. have code this

list<string> username = config.getconfig().getlist(configuration.att_cef_user_name); string result = null;  (string param: user_name .split("\\s", 0)){ for(string user: username ){     string userparam = user.concat("=.*");     if (param.matches(userparam )) {         result = param.split("=")[1];     } }    } 

but problem if string contains spaces in user_name, not work. ex:

string user_name = "id=123 user=aron nicols name=aron app=application"; 

here user has value aron nicols contain spaces. how can write code can me exact user value i.e. aron nicols

if want split on spaces right before tokens have = righ after such user=... maybe add look ahead condition like

split("\\s(?=\\s*=)") 

this regex split on

• \\s space
• (?=\\s*=) has 0 or more * non-space \\s characters ends = after it. look-ahead (?=...) zero-length match means part matched not included in in result split not split on it.

demo:

string user_name = "id=123 user=aron nicols name=aron app=application"; (string s : user_name.split("\\s(?=\\s*=)"))     system.out.println(s); 

output:

id=123 user=aron nicols name=aron app=application 

---

from comment in other answer seems = escaped \ shouldn't treated separator between key=value part of value. in case can add negative-look-behind mechanism see if before = no \, (?<!\\\\) right before require = not have \ before it.
btw create regex match \ need write \\ in java need escape each of \ create \ literal in string why ended \\\\.

so can use

split("\\s(?=\\s*(?<!\\\\)=)") 

demo:

string user_name = "user=dist\\=name1, xyz src=activedirectorydomain ip=10.1.77.24"; (string s : user_name.split("\\s(?=\\s*(?<!\\\\)=)"))     system.out.println(s); 

output:

user=dist\=name1, xyz src=activedirectorydomain ip=10.1.77.24