通过代码来看看吧1.Employee 对象 package test; public class Employee { private int id ; private String name; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } } 2.对象比较器 package test; import java.util.Comparator; public class DemoComparator implements Comparator { public int compare(Object o1, Object o2) { if (((Employee)o1).getId() > ((Employee)o2).getId()) { return -1;//DESC } else if (((Employee)o1).getId() < ((Employee)o2).getId()) ...