java_TreeSet 定制排序实例

package ming;

import java.util.Comparator;
import java.util.TreeSet;

class M {
	int age;

	public M(int age) {
		this.age = age;
	}

	@Override
	public String toString() {
		return "M[age:" + this.age + "]";
	}
}

public class TreeSetTest {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		TreeSet ts = new TreeSet(new Comparator() {
			//重写compare定制排序方法
			public int compare(Object o1, Object o2) {
				M m1 = (M) o1;
				M m2 = (M) o2;

				if (m1.age > m2.age) {
					return 1;
				} else if (m1.age == m2.age) {
					return 0;
				} else {
					return -1;
				}
			}
		});

		ts.add(new M(5));
		ts.add(new M(-3));
		ts.add(new M(9));
		System.out.println(ts);
	}

}