Spring MVC Chart Data from Database

//CanvasjsChartController.java
package com.canvasjs.chart.controllers;
 
import java.util.List;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
 
import com.canvasjs.chart.data.CanvasjsChartData.DataPointModel;
import com.canvasjs.chart.data.CanvasjsChartData.DatabaseConnectionException;
import com.canvasjs.chart.services.CanvasjsChartService;
 
@Controller
@RequestMapping("/canvasjschart")
public class CanvasjsChartController {
 
	@Autowired
	private CanvasjsChartService canvasjsChartService;
 
	@RequestMapping(method = RequestMethod.GET)
	public String springMVC(ModelMap modelMap) {
		List<List<DataPointModel>> canvasjsDataList = canvasjsChartService.getCanvasjsChartData();
		modelMap.addAttribute("dataPointsList", canvasjsDataList);
		return "chart";
	}
 
	@ExceptionHandler({DatabaseConnectionException.class})
	public ModelAndView getSuperheroesUnavailable(DatabaseConnectionException ex) {
	    return new ModelAndView("chart", "error", ex.getMessage());
	}
}                        

//CanvasjsChartService.java
package com.canvasjs.chart.services;
 
import java.util.List;
 
import com.canvasjs.chart.data.CanvasjsChartData.DataPointModel;
 
public interface CanvasjsChartService {
 
	List<List<DataPointModel>> getCanvasjsChartData();
 
}
 
 
//CanvasjsChartServiceImpl.java
package com.canvasjs.chart.services;
 
import java.util.List;
 
import org.springframework.beans.factory.annotation.Autowired;
 
import com.canvasjs.chart.daos.CanvasjsChartDao;
import com.canvasjs.chart.data.CanvasjsChartData.DataPointModel;
 
public class CanvasjsChartServiceImpl implements CanvasjsChartService {
 
	@Autowired
	private CanvasjsChartDao canvasjsChartDao;
 
	public void setCanvasjsChartDao(CanvasjsChartDao canvasjsChartDao) {
		this.canvasjsChartDao = canvasjsChartDao;
	}
 
	@Override
	public List<List<DataPointModel>> getCanvasjsChartData() {
		return canvasjsChartDao.getCanvasjsChartData();
	}
 
}                        

//CanvasjsChartDao.java
package com.canvasjs.chart.daos;
 
import java.util.List;
 
import com.canvasjs.chart.data.CanvasjsChartData.DataPointModel;
 
public interface CanvasjsChartDao {
 
	List<List<DataPointModel>> getCanvasjsChartData();
 
}
 
//CanvasjsChartDaoImpl.java
package com.canvasjs.chart.daos;
 
import java.util.List;
 
import com.canvasjs.chart.data.CanvasjsChartData;
import com.canvasjs.chart.data.CanvasjsChartData.DataPointModel;
 
public class CanvasjsChartDaoImpl implements CanvasjsChartDao {
 
	@Override
	public List<List<DataPointModel>> getCanvasjsChartData() {
		return CanvasjsChartData.getCanvasjsDataList();
	}
 
}                        

//CanvasjsChartData.java
package com.canvasjs.chart.data;
 
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
 
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
 
public class CanvasjsChartData {
 
	private static JdbcTemplate jdbcTemplate;
	static Map<Object,Object> map = null;
	static List<List<DataPointModel>> list = new ArrayList<List<DataPointModel>>();
	static List<DataPointModel> dataPoints1 = new ArrayList<DataPointModel>();
	
	static {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost:3306/canvasjs_db");
        dataSource.setUsername("root");
        dataSource.setPassword("");
        jdbcTemplate = new JdbcTemplate(dataSource);
	}
 
	public static class DataPointModel {
		int x;
		int y;
		
		public int getX() {
			return x;
		}
		public void setX(int x) {
			this.x = x;
		}
		public int getY() {
			return y;
		}
		public void setY(int y) {
			this.y = y;
		}
	}
	
	public static class DatabaseConnectionException  extends RuntimeException{
		
		private static final long serialVersionUID = 1L;
 
		public DatabaseConnectionException(String message) {
			super(message);
		}
	}
	
	private static void getDataPoints(){
        String sql = "select * from datapoints";
        
        try {
        	dataPoints1 = jdbcTemplate.query(sql, new RowMapper<DataPointModel>() {
 
				@Override
				public DataPointModel mapRow(ResultSet rs, int rowNum) throws SQLException {
	            	DataPointModel dataPoint = new DataPointModel();
	     
	            	dataPoint.setX(rs.getInt("x"));
	            	dataPoint.setY(rs.getInt("y"));
	     
	                return dataPoint;
				}});
        }
        catch(Exception e){
        	dataPoints1 = null;
        	throw new DatabaseConnectionException("Error while getting dataPoints");
        }
		list.add(dataPoints1);
	}
	
	public static List<List<DataPointModel>> getCanvasjsDataList() {
		getDataPoints();
		return list;
	}
}