import java.util.Arrays;
 
class Main {
 
	public static void main(String[] args) {
		String pattern = "[02-9]\\d{0,9}";
		String[] strs = {
			"abc4def",       // false (contains non-digits)
			"123456",        // false (starts with '1')
			"234567890123",  // false (length > 10)
			"",              // false (empty)
			"7"              // true
		};
		Arrays.stream(strs)
			.map(str -> str + ": " + str.matches(pattern))
			.forEach(t -> System.out.println(t));
	}
}

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