Question

Please help me to get efficient way to find Numeric String.

String str ="-100000.000";
System.out.println(str.matches("-?\\d+(\\.\\d+)?"));

it works perfectly but I want to accept Numeric Strings like this

String length must be maximum (10,3)--- Example 1234567890.999
String length must be minmum   (1)------0
Numeric String must be positive.

valid Numeric Strings(2.333    1878.12    787          989.0)

Answer 1

Given your restrictions, you can use this regex:

"\\+?\\d{1,10}(\\.\\d{1,3})?"

You can look at the quantifiers section in JavaDoc.

Added the optionally leading +, as per your request in the comment.