public class City implements Serializable{
private static final long serialVersionUID = 1L;
private int id;
private String city_Name;
private int provinces_ID;


public City(int id, String cityName, int provincesID) {
super();
this.id = id;
city_Name = cityName;
provinces_ID = provincesID;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCity_Name() {
return city_Name;
}
public void setCity_Name(String cityName) {
city_Name = cityName;
}
public int getProvinces_ID() {
return provinces_ID;
}
public void setProvinces_ID(int provincesID) {
provinces_ID = provincesID;
}
public static long getSerialversionuid() {
return serialVersionUID;
}
}
  ==================province
public class province implements Serializable {

private static final long serialVersionUID = 1L;
private int id;
private String province_Name;

//方法列表
public province() {
}
public province(int id, String province_Name) {
super();
this.id = id;
this.province_Name = province_Name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getProvince_Name() {
return province_Name;
}
public void setProvince_Name(String province_Name) {
this.province_Name = province_Name;
}
}

2:service 层中
public class City_Province_DB {

查询所有省份
public final List<province> queryProvinces(){
List<province> list = new ArrayList<province>();
String sql = "select *from province ";
ResultSet rs = null;
Statement sta = null;
Connection cn = null;
try {
cn = DbConnection.getConnection();
sta = cn.createStatement();
rs = sta.executeQuery(sql);
while(rs.next()){
list.add(new province(rs.getInt(1),rs.getString(2))); //将查询出来的省放进list中
}
} catch (Exception e) {
// TODO: handle exception
System.out.println("queryProvinces erroy:"+e);
}finally{
try {
rs.close();
sta.close();
cn.close();
} catch (Exception e2) {
// TODO: handle exception
}
}
return list;
}

查询所有城市
public final List<City> queryCity(){
List<City> list = new ArrayList<City>();
String sql = "select * from city";
ResultSet rs = null;
Statement sta = null;
Connection cn = null;
try {
    cn  = DbConnection.getConnection();
sta = cn.createStatement();
rs = sta.executeQuery(sql);
while(rs.next()){
list.add(new City(rs.getInt(1),rs.getString(2),rs.getInt(3)));
}
} catch (Exception e) {
System.out.println("queryCity erroy:"+e);
}finally{
try {
rs.close();
sta.close();
cn.close();
} catch (Exception e2) {
e2.printStackTrace();
}
}
return list;
}
}