省市区三级级联（Ajax+JSP+Servlet+JDBC+Oracle）

package com.dao.impl; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import oracle.jdbc.driver.OracleDriver; import com.dao.SelectDao; import com.entity.Area; import com.entity.City; import com.entity.Province; public class SelectDaoImpl implements SelectDao{ private Connection connection=null; private PreparedStatement pstmt=null; @Override public List<Province> selectProvinces() { List<Province> provinces=new ArrayList<Province>(); ResultSet rs=null; try { Class.forName("oracle.jdbc.driver.OracleDriver"); String url="jdbc:oracle:thin:@localhost:1521:orcl"; String username="ccdust"; String password="asdfgo"; DriverManager.registerDriver(new OracleDriver()); connection=DriverManager.getConnection(url,username,password); pstmt=connection.prepareStatement("select * from province"); rs=pstmt.executeQuery(); while(rs.next()){ Province p=new Province(); p.setPid(rs.getInt("pid")); p.setPname(rs.getString("pname")); provinces.add(p); System.out.println(p.getPname()); } } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return provinces; } @Override public List<City> selectCitys() { List<City> cities=new ArrayList<City>(); ResultSet rs=null; try { Class.forName("oracle.jdbc.driver.OracleDriver"); String url="jdbc:oracle:thin:@localhost:1521:orcl"; String username="ccdust"; String password="asdfgo"; DriverManager.registerDriver(new OracleDriver()); connection=DriverManager.getConnection(url,username,password); pstmt=connection.prepareStatement("select * from city"); rs=pstmt.executeQuery(); while(rs.next()){ City c=new City(); c.setPid(rs.getInt("pid")); c.setCid(rs.getInt("cid")); c.setCname(rs.getString("cname")); cities.add(c); System.out.println(c.getCname()); } } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return cities; } public List<City> selectCitysByPid(int pid) { List<City> cities=new ArrayList<City>(); ResultSet rs=null; try { Class.forName("oracle.jdbc.driver.OracleDriver"); String url="jdbc:oracle:thin:@localhost:1521:orcl"; String username="ccdust"; String password="asdfgo"; DriverManager.registerDriver(new OracleDriver()); connection=DriverManager.getConnection(url,username,password); pstmt=connection.prepareStatement("select * from city where pid=?"); pstmt.setInt(1, pid); rs=pstmt.executeQuery(); while(rs.next()){ City c=new City(); c.setPid(rs.getInt("pid")); c.setCid(rs.getInt("cid")); c.setCname(rs.getString("cname")); cities.add(c); System.out.println(c.getCname()); } } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return cities; } @Override public List<Area> selectAreas() { // TODO Auto-generated method stub return null; } public List<Area> selectAreasByCid(int cid,int pid) { List<Area> areas=new ArrayList<Area>(); ResultSet rs=null; try { Class.forName("oracle.jdbc.driver.OracleDriver"); String url="jdbc:oracle:thin:@localhost:1521:orcl"; String username="ccdust"; String password="asdfgo"; DriverManager.registerDriver(new OracleDriver()); connection=DriverManager.getConnection(url,username,password); pstmt=connection.prepareStatement("select * from area where cid=? and pid=?"); pstmt.setInt(1, cid); pstmt.setInt(2, pid); rs=pstmt.executeQuery(); while(rs.next()){ Area area=new Area(); area.setAid(rs.getInt(1)); area.setCid(rs.getInt(2)); area.setPid(rs.getInt(3)); area.setAname(rs.getString(4)); areas.add(area); System.out.println(area.getAname()); } } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return areas; } }