使用TreeSet存储教室对象，教室对象包括教室号no,教室地址 address,教室容纳人数 count,使用教室号排序。遍历TreeSet.

首先，我们需要创建一个教室类，包含教室号、教室地址和教室容纳人数三个属性，并实现 `Comparable` 接口，以便能够按照教室号进行排序。

public class Classroom implements Comparable<Classroom> {

    private String no;
    private String address;
    private int count;

    public Classroom(String no, String address, int count) {
        this.no = no;
        this.address = address;
        this.count = count;
    }

    public String getNo() {
        return no;
    }

    public void setNo(String no) {
        this.no = no;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public int getCount() {
        return count;
    }

    public void setCount(int count) {
        this.count = count;
    }

    @Override
    public int compareTo(Classroom o) {
        return this.no.compareTo(o.no);
    }
}

接下来，我们创建一个 `TreeSet` 对象，并添加若干教室对象。由于 `TreeSet` 会自动按照元素的自然顺序进行排序，因此我们不需要手动进行排序操作。

import java.util.TreeSet;

public class Main {
    public static void main(String[] args) {
        TreeSet<Classroom> classrooms = new TreeSet<>();
        classrooms.add(new Classroom("101", "教学楼A101", 50));
        classrooms.add(new Classroom("102", "教学楼A102", 80));
        classrooms.add(new Classroom("103", "教学楼A103", 100));

        for (Classroom classroom : classrooms) {
            System.out.println(classroom.getNo() + " " + classroom.getAddress() + " " + classroom.getCount());
        }
    }
}

最后，我们遍历 `TreeSet`，输出每个教室对象的信息。输出结果如下：

101 教学楼A101 50
102 教学楼A102 80
103 教学楼A103 100