Echarts+ajax+java+mysql实现饼图+折线图+柱状图

package com.lgw.dao; 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 com.google.gson.Gson; import com.lgw.bean.Bar; public class BarDao { /** * @author wen * * 鏌ヨ鎵�鏈夋暟鎹� * @return 瀛樻斁鎵�鏈夋暟鎹殑绾挎�ц〃 */ public String query() { ArrayList<Bar> barArr = new ArrayList<Bar>(); try { //JDBC鏂瑰紡杩炴帴MySQL鏁版嵁搴� Class.forName("com.mysql.jdbc.Driver"); Connection conn = DriverManager.getConnection( "jdbc:mysql://localhost:3306/test?characterEncoding=utf8", "root", "123456"); PreparedStatement stmt = conn.prepareStatement("SELECT * FROM bar"); ResultSet rs = stmt.executeQuery(); //灏唗est琛ㄤ腑鐨勬暟鎹瓨鍌ㄥ埌绾挎�ц〃涓� while(rs.next()) { Bar bar = new Bar(); bar.setName(rs.getString("name")); bar.setNum(rs.getInt("num")); barArr.add(bar); } //鍏抽棴杩炴帴 conn.close(); } catch (SQLException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } Gson gson =new Gson(); String str=gson.toJson(barArr); return str; } public void update(String name,Integer num) { try { //JDBC鏂瑰紡杩炴帴MySQL鏁版嵁搴� Class.forName("com.mysql.jdbc.Driver"); Connection conn = DriverManager.getConnection( "jdbc:mysql://localhost:3306/test?characterEncoding=utf8", "root", "123456"); PreparedStatement stmt = conn.prepareStatement("update bar set num='"+num+"' where name='"+name+"'"); stmt.executeUpdate(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } } }