集合框架Set（三）

Set是不重复的集合：

HashSet：根据HashCode来判断元素是否重复，无序。

TreeSet：根据compare方法判断大小，有顺序。代码如下：

/**
 * @author E-mail: 
 * @version 创建时间：2018/5/14 10:58 AM
 * 类说明
 */
public class Number1
        implements Comparable<Number1> {
    int max;
    int min;
    int index;

    public int getMax() {
        return max;
    }

    public void setMax(int max) {
        this.max = max;
    }

    public int getMin() {
        return min;
    }

    public void setMin(int min) {
        this.min = min;
    }

    public int getIndex() {
        return index;
    }

    public void setIndex(int index) {
        this.index = index;
    }

    public Number1(int a, int b, int c) {
        this.min = a;
        this.max = b;
        this.index = c;
    }

    @Override
    public int compareTo(Number1 o) {
        return Integer.compare(this.max - this.min, o.max - o.min);
    }
}

import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;

/**
 * @author E-mail: 
 * @version 创建时间：2018/5/14 10:57 AM
 * 类说明
 */
public class Test {
    public static void main(String[] argv) {
        TreeSet set = new TreeSet<Number1>();
        Number1 number1 = new Number1(1, 5, 1);
        Number1 number2 = new Number1(1, 3, 2);
        Number1 number3 = new Number1(3, 12, 3);
        Number1 number4 = new Number1(2, 3, 4);
        set.add(number1);
        set.add(number2);
        set.add(number3);
        set.add(number4);
        for (Iterator<Number1> iterator = set.iterator(); iterator.hasNext(); ) {
            System.out.print(iterator.next().getIndex() + " ");
        }
    }
}