How to check if a String is numeric in Java

Question

How would you check if a String was a number before parsing it?

Answer 1

A well-performing approach avoiding try-catch and handling negative numbers and scientific notation.

Pattern PATTERN = Pattern.compile( "^(-?0|-?[1-9]\\d*)(\\.\\d+)?(E\\d+)?$" );

public static boolean isNumeric( String value ) 
{
    return value != null && PATTERN.matcher( value ).matches();
}