public class BTListInfo {

	private String btmac;

	public BTListInfo(String bt_mac) {
		this.btmac = bt_mac;
	}

	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj != null && obj.getClass() == BTListInfo.class) {
			BTListInfo r = (BTListInfo) obj;
			return this.btmac == r.btmac;
		}
		return false;
	}

	public String getBTmac() {
		return btmac;
	}

	public void setBTmac(String bt_mac) {
		this.btmac = bt_mac;
	}
}

BTListInfo b=new BTListInfo(String btmac);
if(list.contains(b)){

}