servlet创建增删该查和servlet实现echarts多条折线图

package com.service;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.Statement;import java.util.ArrayList;import java.util.List;import java.util.UUID;import com.dao.CarInfo;import com.dao.DateInfo;import com.db.util;public class HandleImpl implements IHandle {public boolean add(CarInfo carInfo) {boolean flag = false;Connection conn = null;PreparedStatement pst = null;String sql = "insert into car_info(id,car_number)values(?,?)";try {conn = util.getConnection();pst = (PreparedStatement) conn.prepareStatement(sql);UUID uuid=UUID.randomUUID();String id = uuid.toString();pst.setString(1, id);pst.setString(2, carInfo.getCarNumber());int rows = pst.executeUpdate();if (rows > 0) {flag = true;}} catch (Exception e) {e.printStackTrace();} finally {util.close(pst, conn);}return flag;}public List<CarInfo> getCarInfos() {List<CarInfo> list = new ArrayList<CarInfo>();Connection conn = null;ResultSet rs = null; //!!!!!!!Statement stmt = null; try{ conn = util.getConnection(); String sql = "select id,car_number from car_info"; stmt = conn.createStatement(); rs = stmt.executeQuery(sql); while( rs.next()){ CarInfo ci = new CarInfo(); ci.setId(rs.getString("id")); ci.setCarNumber(rs.getString("car_number")); list.add(ci); } }catch (Exception e) { e.printStackTrace(); }finally{util.close(rs, stmt, conn); } return list; }public List<DateInfo> getDateInfos() {List<DateInfo> list = new ArrayList<DateInfo>();Connection conn = null;ResultSet rs = null; //!!!!!!!Statement stmt = null; try{ conn = util.getConnection(); String sql = "select d.id,d.date_time,d.park_time from car_info cn LEFT JOIN date_info d ON cn.id = d.car_id where car_number='陕A111'"; stmt = conn.createStatement(); rs = stmt.executeQuery(sql); while( rs.next()){ DateInfo di = new DateInfo(); di.setId(rs.getString("id")); di.setDateTime(rs.getString("date_time")); di.setParkTime(rs.getString("park_time")); list.add(di); } }catch (Exception e) { e.printStackTrace(); }finally{util.close(rs, stmt, conn); } return list; }public List<DateInfo> getDateInfosB() {List<DateInfo> list = new ArrayList<DateInfo>();Connection conn = null;ResultSet rs = null; //!!!!!!!Statement stmt = null; try{ conn = util.getConnection(); String sql = "select d.id,d.date_time,d.park_time from car_info cn LEFT JOIN date_info d ON cn.id = d.car_id where car_number='陕B222'"; stmt = conn.createStatement(); rs = stmt.executeQuery(sql); while( rs.next()){ DateInfo di = new DateInfo(); di.setId(rs.getString("id")); di.setDateTime(rs.getString("date_time")); di.setParkTime(rs.getString("park_time")); list.add(di); } }catch (Exception e) { e.printStackTrace(); }finally{util.close(rs, stmt, conn); } return list; }public List<DateInfo> getDateInfosC() {List<DateInfo> list = new ArrayList<DateInfo>();Connection conn = null;ResultSet rs = null; //!!!!!!!Statement stmt = null; try{ conn = util.getConnection(); String sql = "select d.id,d.date_time,d.park_time from car_info cn LEFT JOIN date_info d ON cn.id = d.car_id where car_number='陕C333'"; stmt = conn.createStatement(); rs = stmt.executeQuery(sql); while( rs.next()){ DateInfo di = new DateInfo(); di.setId(rs.getString("id")); di.setDateTime(rs.getString("date_time")); di.setParkTime(rs.getString("park_time")); list.add(di); } }catch (Exception e) { e.printStackTrace(); }finally{util.close(rs, stmt, conn); } return list; }//@Overridepublic boolean del(String id) {boolean flag = false;Connection conn = null;PreparedStatement pst = null;String sql = "delete from car_info where id =" "'" id "'";try { conn = util.getConnection(); pst = (PreparedStatement) conn.prepareStatement(sql); int rows = pst.executeUpdate();if (rows > 0) {flag = true;}} catch (Exception e) {e.printStackTrace();} finally {util.close(pst, conn);}return flag;}public CarInfo getCarInfoById(String id) {Connection conn = null;ResultSet rs = null;Statement stmt = null;CarInfo ci = new CarInfo();try {conn = util.getConnection();String sql = "select * from car_info where id =" "'" id "'";stmt = conn.createStatement();rs = stmt.executeQuery(sql);while (rs.next()) {if (rs.getString("id").equals(id)) {ci.setId(id);ci.setCarNumber(rs.getString("car_number"));}}} catch (Exception e){e.printStackTrace();} finally{util.close(rs, stmt, conn);}return ci;}public boolean update(CarInfo ci) {boolean flag = false;Connection conn = null;java.sql.PreparedStatement pst = null;conn = util.getConnection();String sql = "update car_info set car_number=? where id =" "'" ci.getId() "'";try {pst = conn.prepareStatement(sql);pst.setString(1, ci.getCarNumber());int rows = pst.executeUpdate();if (rows > 0){flag = true;}} catch (Exception e){e.printStackTrace();}finally{util.close(pst, conn);}return flag;}}