代码如下：

public class NetBar {
	private int age;

	public int getAge() {
		return age;
	}
	public void setAge(int age) throws Exception {
		if (age < 18) {
			throw new Exception("年龄未满18,不能进入网吧。");
		} else {
			throw new Exception("年龄合格");
		}
	}
	public static void main(String[] args) {
		NetBar netBar = new NetBar();
		try {
			netBar.setAge(16);
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
	}
}

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