import java.util.Arrays;
import java.util.stream.Collectors;
 
public class Main {
	public static void main(String[] args) {
		String str = "snake_case_to_camel_case";
 
		str = str.indexOf("_") != -1
				? str.substring(0, str.indexOf("_")) + 
					Arrays.stream(str.substring(str.indexOf("_") + 1).split("_"))
						.map(s -> Character.toUpperCase(s.charAt(0)) + s.substring(1)).collect(Collectors.joining())
				: str;
 
		System.out.println(str);
	}
}

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