jqplot通过ajax动态画折线图的方法及思路

效果如图所示，每个五秒钟图会移动一次（其实是重新画了一张图），能显示所监控的cpu信息。

pastCpuInfomation函数主要用来显示一张折线图

updateCpuPic函数把5秒前的图去掉，重新根据现有数据画一张图。

updateCpuInfomation函数 把最新的点加入存储折线的数组中

再接着在界面中弄两个定时器，让他们每个5秒执行一次updateCpuPic，每个1分钟执行一次updateCpuInfomation，图画就动起来了。

PS：代码中执行好多操作前都会在服务器中获取下服务器的当前时间 ，ajax写得有点乱，我也不知道规不规范，实现动态图的方法好像也不是太好，最好是能直接更新线的数据的，希望朋友们多多指教！画表的代码已经标红（30行到60行）

var past_cpu_service_statistics_line = new Array();
var plot;
function pastCpuInfomation() {
    // 历史cpu数据
    // 本地时间    $.ajax({
        type: "POST",
        contentType: "application/x-www-form-urlencoded;charset=UTF-8",
        url: globalObj.path + '/server/getServerCurrentTime.htm',
        success: function(currentTime){
            console.log("取到服务器时间"+currentTime);
            //获取历史cpu数据
            $.ajax({
                type: "POST",
                contentType: "application/x-www-form-urlencoded;charset=UTF-8",
                url: globalObj.path + '/server/getPastCpuMonitorData.htm',
                // startTime endtime 是伪数据，时间在后台获取
                data: "hostName=" + "login.cheos.cn",
                success: function(result){
                    for (key in result) {
                        // 去得到时间转化为int
                        var intKey = parseInt(key);
                        var transferTime = new Date(intKey);
                        console.log("transferTime:"+ key + "----resut:" + transferTime);
                        var onePoint = [transferTime, result[key] ];
                        past_cpu_service_statistics_line.push(onePoint);
                    }
                   <span style="color:#ff0000;"> // 历史cpu情况表
                    plot= $.jqplot('cpuHistory',[ past_cpu_service_statistics_line ],
                            {
                                axes: {
                                    xaxis: {
                                        label: '时间',
                                        renderer: $.jqplot.DateAxisRenderer,
                                        tickOptions: {
                                            formatString: '%Y-%#m-%d %H:%M'
                                        },
                                        min : (currentTime -1000 * 60 * 60),
                                        max: (currentTime),
                                    // 横（纵）坐标显示的最小值
                                    // ticks:['']
                                    },
                                    yaxis: {
                                        label: 'cpu监控',
                                    }
                                },
                                highlighter: {
                                    show: true,
                                    sizeAdjust : 7.5
                                },
                                cursor: {
                                    show: false
                                }
                            });
 </span>
                },
                error: function(textStatus){
                    alert("获取监控信息失败!");
                }
            });
            //获取历史cpu数据ajax结束
        },
        error: function(textStatus){
            alert("取历史cpu数据时候获取服务器时间失败!");
        }
    });     
}
function updateCpuPic() {
    console.log("正在更新cpu视图");
//先取得服务器时间，用来画横坐标
    $.ajax({
        type: "POST",
        contentType: "application/x-www-form-urlencoded;charset=UTF-8",
        url: globalObj.path + '/server/getServerCurrentTime.htm',
        success: function(result){
            var intKey =parseInt(result);
            var transferTime = new Date(intKey);
            console.log("获取到服务器时间："+result+"------"+transferTime);
        //操作图表
            //如果已经存在图表，则摧毁
            if (plot) {
                // plot.destory();
                $("#cpuHistory").unbind();
                $("#cpuHistory").empty();
                plot= null;
            }
            //重新画图表
            plot= $.jqplot('cpuHistory',[ past_cpu_service_statistics_line ], {
                axes: {
                    xaxis: {
                        label: '时间',
                        renderer: $.jqplot.DateAxisRenderer,
                        tickOptions: {
                            formatString: '%Y-%#m-%d %H:%M'
                        },
                        min: (result - 1000 * 60 * 60),
                        max: (result),
                    // 横（纵）坐标显示的最小值
                    // ticks:['']
                    },
                    yaxis: {
                        label: 'cpu监控',
                    }
                },
                highlighter: {
                    show: true,
                    sizeAdjust: 7.5
                },
                cursor: {
                    show: false
                },
                replot: {
                    resetAxes: true
                }
            });
        },
        error: function(textStatus){
            alert("获取服务器时间失败!");
        }
    });
 
}
function updateCpuInfomation() {
    $.ajax({
        type: "POST",
        contentType: "application/x-www-form-urlencoded;charset=UTF-8",
        url: globalObj.path + '/server/getLatestCpuMonitorData.htm',
        data: "hostName=" + "login.cheos.cn",
        success: function(result){
            // 更新一次数据
            for (key in result) {
                var intKey = parseInt(key);
                var transferTime = new Date(intKey);
                console.log("----------------更新cpu信息---:" + key + "----更新时间:" + transferTime);
                var onePoint = [transferTime, result[key] ];
                past_cpu_service_statistics_line.push(onePoint);
            }
            // 更新图表
        //  updateCpuPic();
        },
        error: function(textStatus){
            alert("更新cpu信息失败!");
        }
    });
}