Question

我从CSV文件中读取了以下数据：

Class    Total     Step     Run1    Run2   Run3    Run4
Timer    15        2        10.5    3.6    5.5     8

稍后，将添加其他类，并具有可变的运行大小。例如，将添加具有6次运行的类Optimiser，并且CSV类似于：

Class     Total     Step     Run1    Run2   Run3    Run4
Timer     15        2        10.5    3.6    5.5     8
Optimiser 26        6        6       10     5       1.5    16    9

如您所见，标头缺少Run5和Run6。

我的问题是如何更新标题以包括新的列名？请注意，稍后可能会添加其他类，并且运行次数超过6。

我编写的要写入CSV的代码是：

  try {
            BufferedWriter out = new BufferedWriter(new FileWriter(f, true));
            if (f.length() == 0L) {
                out.write("Class");
                out.write(",");
                out.write("Total");
                out.write(",");
                out.write("Step");
                out.write(",");
                for(int i=1; i<=numRuns; i++) {
                    out.write(String.valueOf(i));
                    out.write(",");
                }
                out.write("\n");
            }

            for(int i=0; i<classes.size(); i++) {
                out.write(classes.get(i));
                out.write(",");

                out.write(totals.get(i));
                out.write(",");

          out.write(steps.get(i));
                out.write(",");

                List<Double> runs = this.getRuns(classes.get(i));
                for(double x: runs) {
                    out.write(String.valueOf(x));
                    out.write(",");
                }
                out.write("\n");
            }
            out.close();

        } catch (IOException e) {
            e.printStackTrace();
        }

Answer 1

在进入写入步骤之前，您应该知道任何行的最大运行次数您可以通过

int numRuns = 0
for (int i=0; i<classes.size(); i++) {
    int rowSize = this.getRuns(classes.get(i));
    if (rowSize > numRows) {
        numRuns = rowSize;
    }
}

如何在CSV文件中附加到特定行

1 个答案: