How do I write a regex in java which allow only numbers 0-9 and # -

i want user input numbers 0-9 , '#' no spaces, no alphabets , no other special characters.

for ex:

12736#44426 :true 263 35# :false 2376shdbj# :false  3623t27# :false #? :false 

here's code:

boolean valid(string str)     {         if(str.matches("[0-9]+|(\\#)"))         return true;          else          return false;      } 

but returns false 3256#

i tried [0-9]+|(#)

i noob @ regular expressions.

any appreciated.

tell me if not clear.

you can use regex this:

^[\d#]+$ 

working demo

the idea match digits , symbol # using using pattern [\d#] , can many 1 or many times (using +). , ensure line starts , ends characters use anchors ^ (start of line) , $ (end of line).

for java remember escape backslahes as:

^[\\d#]+$ 

the java code can use can be:

pattern pattern = pattern.compile("^[\\d#]+$"); matcher matcher = pattern.matcher(your text here);  if (matcher.find()) {     system.out.println("matches!"); } 

or also:

if ("your string here".matches("^[\\d#]+$")) {     system.out.println("matches!"); } 

if want know more usage can check link:

http://www.vogella.com/tutorials/javaregularexpressions/article.html#regexjava