Почему, собственно, неверно?
package com.javarush.task.task04.task0420;
import java.io.BufferedReader;
import java.io.InputStreamReader;
/*
Сортировка трех чисел
*/
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
int a2 = Integer.parseInt(reader.readLine());
int b2 = Integer.parseInt(reader.readLine());
int c2 = Integer.parseInt(reader.readLine());
BtoL(a2,b2,c2);
}
static void BtoL(int a, int b, int c) {
if ((a < b) && (a < c) && (b < c))
System.out.print(c + " " + b + " " + a);
else if ((b < a) && (b < c) && (a < c))
System.out.print(c + " " + a + " " + b);
else if ((c < a) && (c < b) && (a < b))
System.out.print(b + " " + a + " " + c);
}
}