我想在图中添加标签

我得到的是

我无法将这些系列名称添加到上面的图形中（使用excel绘制）。
代码在这里

// Population in 2005

        Random rand = new Random();

        // Generate random integers in range 0 to 999
        //int rand_int1 = rand.nextInt(1000);
        /*for(int i=0;i<12;++i){
            dataset.addValue(status(code.getText(),dater(i)), "Status", monthname(i));
            }*/
        for(int i=0;i<12;++i){
        dataset.addValue(2500+rand.nextInt(1000), "USA", String.valueOf(2000+i));
        dataset.addValue(2000+rand.nextInt(1000), "India", String.valueOf(2000+i));
        dataset.addValue(1500+rand.nextInt(1000), "China", String.valueOf(2000+i));
        }

        JFreeChart barChart = ChartFactory.createLineChart(analysisof(code.getText()), "Year", "Amount", dataset, PlotOrientation.VERTICAL, false, true, false);
        CategoryPlot barchrt = barChart.getCategoryPlot();
        barchrt.setRangeGridlinePaint(Color.orange);
        ChartPanel barpanel = new ChartPanel(barChart);
        panelchart.removeAll();
        panelchart.add(barpanel,BorderLayout.CENTER);
        panelchart.validate();
        this.repaint();