前段时间因为项目需要使用了highcharts报表，新手可以参考http://www.hcharts.cn/，教程中有比较详细的介绍和demo。但是demo中的例子的数据都是静态数据，而在实际项目中一般数据都是从数据库加载的。
下面是我做的一个简单例子，从数据库中加载数据然后在前端使用highcharts渲染。
读取数据库数据使用的servlet，可以根据需要改成其他（如spring等）。servlet主要代码如下：
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
Connection conn = null;
String sql;
String url = "jdbc:mysql://192.168.1.203:3306/test?user=opuser&password=opuser1111&useUnicode=true&characterEncoding=UTF8";
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(url);
Statement stmt = conn.createStatement();
sql = "select * from test";
ResultSet rs = stmt.executeQuery(sql);
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
while (rs.next()) {
System.out.println(rs.getString(1) + " " + rs.getString(2) + " " + rs.getString(3));
Map<String, Object> map = new HashMap<String, Object>();
map.put("datetime", rs.getString(2));
map.put("data", Double.parseDouble(rs.getString(3)));
list.add(map);
}
Gson gson = new Gson();
String g = gson.toJson(list);
PrintWriter out = response.getWriter();
out.println(g);
out.flush();
out.close();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}本例中返回的数据格式是json。
程序中使用了mysql和gson的jar包，请自行下载。因为都是比较常用的jar包，在此就不提供下载地址了。
然后是jsp代码如下：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>HighChartsTest</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<!-- <script type="text/javascript" src="js/jquery-1.8.3.min.js"></script>
<script type="text/javascript" src="js/highcharts.js"></script> -->
<script type="text/javascript" src="http://cdn.hcharts.cn/jquery/jquery-1.8.3.min.js"></script>
<script type="text/javascript" src="http://cdn.hcharts.cn/highcharts/highcharts.js"></script>
<script>
//图表属性，不包含数据
var options = {
chart: {
renderTo:'container',
type:'spline',
},
title: {
text: '实时温度曲线',
x: -20 //center
},
xAxis:{
},
yAxis: {
title: {
text: 'Temperature (°C)'
},
plotLines: [{
value: 0,
1,
color: '#808080'
}]
},
series: [{
name:'温度',
}],
tooltip: {
valueSuffix: '°C'
},
plotOptions: {
spline:{
dataLabels: {
enabled: true
},
animation:false,
},
},
};
//初始函数，设置定时器，定时取数据
$(function () {
queryData(0);
var i=0;
var timer = setInterval(function(){
i++;
if(i>=3) {i=0;}
queryData(i);
},3000);
//停止刷新
$("button").click(function(){
clearInterval(timer);
});
});
var categories = [];
var datas = [];
//Ajax 获取数据并解析创建Highcharts图表
function queryData(index) {
$.ajax({
url:'servlet/HighCharts',
type:'get',
dataType:"json",
success:function(data) {
$.each(data,function(i,n){
categories[i] = n["datetime"];
datas[i] = n["data"];
});
options.xAxis.categories = categories;
options.series[0].data = datas;
chart = new Highcharts.Chart(options);
}
});
}
</script>
</head>
<body>
<div id="container" style="min-800px;height:400px;"></div>
<p align=center><button>停止刷新</button></p>
</body>
</html>
