代码：
package test; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.Arrays; import java.util.Comparator; import java.util.Scanner; public class myTest { /** * @param args * @throws IOException */ public static void main(String[] args) throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); // Scanner scanner = new Scanner(System.in); // while(scanner.hasNext()) { while (true) { // String string = scanner.nextLine(); String string = br.readLine(); String[] s = string.split(" "); Arrays.sort(s, new Comparator<String>() { @Override public int compare(String o1, String o2) { return o1.compareTo(o2);// 升序排序 // return o2.compareTo(o1); // 降序排序 } }); int number = s.length; StringBuffer outString = new StringBuffer(); for (int k = 0; k < number; k++) { outString.append("-" + s[k]); } System.out.println(outString); } } }运行结果： 输入（空格隔开）： 45 123 12 0 输出： -0-12-123-45
扩展：Comparable和Comparator的区别
