regex - Java simple regular expression -

i want specify regex finds if there non letter non number chars in string.

basically want accept [a-z][a-z][0-9] in order combination..i.e "2a4a44awa" should valid.

how can this?

instead of:

[a-z][a-z][0-9]  

match with:

[a-za-z0-9]+ 

from api:

greedy quantifiers x?  x, once or not @ x*  x, 0 or more times x+  x, 1 or more times x{n}    x, n times x{n,}   x, @ least n times x{n,m}  x, @ least n not more m times