Java系列：jfreechart动态绘制折线图

一、概述：
1.导入jfreechart-1.0.14.jar包
2.实时插入数据
3.获取where条件子句
4.自定义SQL语句
5.拼接SQL 并执行遍历
6.获取jfreechart数据源
7.制作jfreechart折线图
8.获取json{共几页,当前页码,共几条,起始条数,终止条数,数据list}
二、oracle数据库设计
ELECTR_EQU表

ELECTR_DATA表

三、代码实例

package electricityMonitor;

import java.awt.*;
import java.sql.*;
import org.jfree.chart.renderer.xy.XYItemRenderer;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.chart.title.TextTitle;
import org.jfree.data.time.*;
import org.json.*;
import java.text.*;
import java.util.*;
import java.util.Date;
import java.util.Timer;
import org.jfree.chart.*;
import org.jfree.chart.plot.*;

public class ElectricityMonitor {
    private static String USERNAMR = "mine";
    private static String PASSWORD = "mine";
    private static String DRVIER = "oracle.jdbc.OracleDriver";
    private static String URL = "jdbc:oracle:thin:@192.168.100.57:1521:orcl";

    Connection connection = null;
    PreparedStatement pstm = null;
    ResultSet rs = null;
    static String equidRs;

    private static ElectricityMonitor instance = null;
    public static ElectricityMonitor getInstance() {
        if (instance == null) instance = new ElectricityMonitor();
        return instance;
    }

    //实时插入数据
    private ElectricityMonitor() {
        connection = getConnection();
        TimerTask task = new TimerTask() {
            public void run() {
                insertData();
            }
        };
        Timer timer = new Timer();
        long delay = 0;
        long intevalPeriod = 1 * 1000;
        timer.scheduleAtFixedRate(task, delay, intevalPeriod);
    }

    //获取where条件子句
    private String getWhereStr(String condition){
        String ret = "";
        try {
            JSONObject obj = new JSONObject(condition);
            String areaname = obj.getString("areaname");
            String equid = obj.getString("equid");
            String equname = obj.getString("equname");
            if (! areaname.trim().equals("")) {
                ret += String.format(" areaname = '%s' ", areaname);
            }
            if (! equid.trim().equals("")) {
                if (!ret.equals("")) ret += " and ";
                ret += String.format(" equid = '%s' ", equid);
            }
            if (! equname.trim().equals("")) {
                if (!ret.equals("")) ret += " and ";
                ret += String.format(" equname = '%s'", equname);
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        return ret;
    }

    private boolean containField(String fieldList, String field) {
        if (fieldList.equals("*")) return true;
        fieldList = fieldList.toUpperCase();
        field = field.toUpperCase();
        return (fieldList.indexOf(field) > -1);
    }

    //获取json{共几页,当前页码,共几条,起始条数,终止条数,数据list}
    public String query(String qSubstation, String condition, String fields, int pageNum) {
        String whereStr = getWhereStr(condition);
        String sql = String.format(
                " select %s from electr_equ where substation = '%s' %s ",
                fields, qSubstation, (whereStr.equals(""))? "" : " and " + whereStr
        );

        try {
            int totalRecords = 0;
            pstm = connection.prepareStatement(sql);
            rs = pstm.executeQuery();

            StringBuffer buff = new StringBuffer();
            boolean firstRow = true;
            int recordStart = (pageNum - 1) * 10 + 1;
            int recordEnd   = (pageNum - 1) * 10 + 1;
            while (rs.next()) {
                totalRecords ++;
                if (totalRecords < recordStart) continue;
                if (totalRecords > recordEnd) continue;

                String row = "";
                if (containField(fields, "substation")) {
                    String substation = rs.getString("substation");
                    if (!row.equals("")) row = ", ";
                    row += String.format("\"%s\"", substation);
                }
                if (containField(fields, "areaname")) {
                    String areaname = rs.getString("areaname");
                    if (!row.equals("")) row = ", ";
                    row += String.format("\"%s\"", areaname);
                }
                if (containField(fields, "i_a")) {
                    String i_a = rs.getString("i_a");
                    if (!row.equals("")) row = ", ";
                    row += String.format("%.2f", i_a);
                }
                if (containField(fields, "u_a")) {
                    String u_a = rs.getString("u_a");
                    if (!row.equals("")) row = ", ";
                    row += String.format("%.2f", u_a);
                }
                if (containField(fields, "w_a")) {
                    String w_a = rs.getString("w_a");
                    if (!row.equals("")) row = ", ";
                    row += String.format("%.2f", w_a);
                }
                if (firstRow) buff.append(",\n");
                else firstRow = false;
                buff.append(row);
            }
            int totalPages = (totalRecords % 10 == 0)? (totalRecords/10) : ((totalRecords/10) + 1);
            if (recordEnd > totalRecords) recordEnd = totalRecords;
            if (pageNum > totalPages) pageNum = totalPages;
            String dataStr = buff.toString();
            String dataJson=String.format(
                    "{\"totalRecords\": %d, " +
                            "\"recordStart\": %d, " +
                            "\"recordEnd\": %d, " +
                            "\"totalPages\": %d, " +
                            "\"pageNumber\": %d, " +
                            "\"data\": [\n%s\n]" +
                            "}",
                    totalRecords,
                    recordStart,
                    recordEnd,
                    totalPages,
                    pageNum,
                    dataStr
            );
            return dataJson;
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ReleaseResource();
        }
        return null;
    }

    //自定义SQL语句
    private void insertData(){
        String sql ="insert into electr_data(substation,equid,equname,areaname,i_a,u_a,w_a,data_time) " +
                "select substation,equid,equname,areaname,i_a,u_a,w_a,sysdate from electr_equ";
        try {
            pstm = connection.prepareStatement(sql);
            pstm.executeQuery();
        } catch (SQLException e){
            e.printStackTrace();
        }finally {
            ReleaseResource();
        }
    }

    //定义HashMap
    public HashMap<String, Vector> hash = new HashMap<String, Vector>();

    //拼接SQL 并执行遍历获取jfreechart数据源
    public void drawChart(String substation, String condition, String col, String dtStart, String dtEnd) {
        Second sec = null;
        Statement  stat = null;
        String whereStr = getWhereStr(condition);
        String sql = String.format(
                "select  equid , equname , %s, d2c(data_time) from electr_data where substation = '%s' %s ",
                col, substation, (whereStr.equals("")) ? "" : " and " + whereStr
        );
        boolean startNull = dtStart.equals("");
        boolean endNull = dtEnd.equals("");
        if (startNull && endNull) {
            sql += " and data_time <= sysdate";
            sql += " and data_time >= sysdate-8.0/24.0";
        }
        else if (startNull && (!endNull)) {
            sql += " and data_time >= c2d('" + dtEnd + ":00') - 8.0/24.0";
            sql += " and data_time <= c2d('" + dtEnd + ":00')";
        }
        else if ((!startNull) && endNull) {
            sql += " and data_time >= c2d('" + dtStart + ":00')";
        }
        else {
            sql += " and data_time >= c2d('" + dtStart + ":00')";
            sql += " and data_time <= c2d('" + dtEnd + ":00')";
        }
        try {
            stat = connection.createStatement();
            rs = stat.executeQuery(sql);
            while (rs.next()){
                equidRs=rs.getString(1);
                String name = rs.getString(2);
                float colValue  = rs.getFloat(3);
                String time = rs.getString(4);
                int year  = Integer.parseInt(time.substring(0,4));
                int mont  = Integer.parseInt(time.substring(5,7));
                int iday  = Integer.parseInt(time.substring(8,10));
                Day day = new Day(iday, mont, year);
                int iHour = Integer.parseInt(time.substring(11,13));
                Hour hour = new Hour(iHour, day);
                int iMinu = Integer.parseInt(time.substring(14,16));
                Minute minu = new Minute(iMinu, hour);
                int iSec = Integer.parseInt(time.substring(17,19));
                sec = new Second(iSec, minu);
                Vector v=hash.get(equidRs);
                if(v == null) {
                    v = hash.put(equidRs, new Vector());
                }else{
                    v.add(sec);
                    v.add(colValue);
                }
            }
            rs.close();
            String rangeAxis;
            if(col.equals("i_a")){
                rangeAxis="电流";
            }else if(col.equals("u_a")){
                rangeAxis="电压";
            }else{
                rangeAxis="功率";
            }

            StandardChartTheme mChartTheme = new StandardChartTheme("CN");
            mChartTheme.setLargeFont(new Font("黑体", Font.PLAIN, 15));
            mChartTheme.setExtraLargeFont(new Font("黑体", Font.PLAIN, 15));
            mChartTheme.setRegularFont(new Font("黑体", Font.PLAIN, 15));
            ChartFactory.setChartTheme(mChartTheme);
            TimeSeriesCollection dataset=GetCollection(hash);
            JFreeChart timeSeriesChart = ChartFactory.createTimeSeriesChart(
                    "折线图",     //图表标题
                    "时间",      //X轴标题
                    rangeAxis,       //Y轴标题
                    dataset,    //绘图数据集
                    true,       //显示图例
                    true,       //采用标准生成器
                    false);     //是否生成超链接

            //设置主标题
            timeSeriesChart.setTitle(new TextTitle(substation, new Font("宋体",  Font.PLAIN, 18)));

            //获取图表区域对象
            XYPlot plot = timeSeriesChart.getXYPlot();
            XYItemRenderer r = plot.getRenderer();
            if(r instanceof XYLineAndShapeRenderer) {
                XYLineAndShapeRenderer axis = (XYLineAndShapeRenderer)r;
                axis.setBaseShapesVisible(true);
                axis.setBaseShapesFilled(true);
                axis.setDrawSeriesLineAsPath(true);
            }

            ChartFrame mChartFrame = new ChartFrame("折线图", timeSeriesChart);
            mChartFrame.pack();
            mChartFrame.setVisible(true);
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            if (stat!=null){
                try {
                    stat.close();
                    stat=null;
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            ReleaseResource();
        }
    }

    //获取绘图数据集
    public static TimeSeriesCollection GetCollection(HashMap<String, Vector> hash){
        TimeSeriesCollection dataset = new TimeSeriesCollection();
        Iterator iter = hash.entrySet().iterator();
        while (iter.hasNext()){
            Map.Entry entry = (Map.Entry) iter.next();
            Object key = entry.getKey();
            Object val = entry.getValue();
            String[] arr = val.toString().split(",");
            TimeSeries timeSeries = new TimeSeries("ID:"+(Comparable) key);
            for (int i = 0; i < arr.length; i++) {
                if ((2 * i + 1) < arr.length) {
                    String t = arr[2 * i].replace('[', ' ').replace(']', ' ').trim();
                    String a = arr[2 * i + 1].replace('[', ' ').replace(']', ' ').trim();
                    Date date1 = new Date(t);
                    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    String sDate = sdf.format(date1);
                    int year  = Integer.parseInt(sDate.substring(0,4));
                    int mont  = Integer.parseInt(sDate.substring(5,7));
                    int iday  = Integer.parseInt(sDate.substring(8, 10));
                    Day day = new Day(iday, mont, year);
                    int iHour = Integer.parseInt(sDate.substring(11,13));
                    Hour hour = new Hour(iHour, day);
                    int iMinu = Integer.parseInt(sDate.substring(14,16));
                    Minute minu = new Minute(iMinu, hour);
                    int iSec = Integer.parseInt(sDate.substring(17,19));
                    Second sec1 = new Second(iSec, minu);
                    timeSeries.addOrUpdate(sec1, Double.parseDouble(a));
                }
            }
            dataset.addSeries(timeSeries);
        }
        return dataset;
    }

    public static void main(String[] args){
        ElectricityMonitor em=new ElectricityMonitor();
        em.drawChart("变电所1","{\"equid\": \"\",\"equname\": \"\",\"areaname\": \"\"}","i_a","","2018-1-8 15:00");
    }

    public Connection getConnection(){
        try {
            Class.forName(DRVIER);
            connection = DriverManager.getConnection(URL, USERNAMR, PASSWORD);
            System.out.println("成功连接数据库");
        } catch (ClassNotFoundException e) {
            throw new RuntimeException("class not find !", e);
        } catch (SQLException e) {
            throw new RuntimeException("get connection error!", e);
        }
        return connection;
    }

    public void ReleaseResource(){
        if (rs != null) {
            try {
                rs.close();
                rs=null;
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (pstm != null) {
            try {
                pstm.close();
                pstm=null;
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}