一种解析制表符分隔文件策略 [英] A strategy for parsing a tab-separated file

问题描述

什么是解析Java中的制表符分隔文件的最原始的方式，使表格数据不会丢失的结构？我的不可以寻找一种方式，用豆或Jsoup做到这一点，因为他们不熟悉我，初学者。我需要什么是它背后的逻辑，什么是做它的有效途径，例如，如果我有像

What would be the most primitive way of parsing a tab-separated file in Java, so that the tabular data would not lose the structure? I am not looking for a way to do it with Bean or Jsoup, since they are not familiar to me, a beginner. I need advice on what would be the logic behind it and what would be the efficient way to do it, for example if I have a table like

ID reference | Identifier    | Type 1| Type 2  | Type 3 |
1            | red#01        | 15%   |  20%    | 10%    |
2            | yellow#08     | 13%   |  20%    | 10%    |

更正：在这个例子中我有类型1 - 3，但我的问题适用于N多的种类

Correction: In this example I have Types 1 - 3, but my question applies to N number of types.

我可以做到，只需使用数组或有在Java中不同的数据结构，将成为这个任务的更好的表解析？这是我觉得我应该这样做：

Can I achieve table parsing by just using arrays or is there a different data structure in Java that would be better for this task? This is how I think I should do it:

1. 扫描/读取\\ t的第一行分裂并创建一个字符串数组。


2. 拆分成数组每个子阵列
1表标题的子阵

3. 之后，开始读取表中的下一行，并且对于每个子阵列，由列添加相应的值。

1. Scan/read the first line splitting at "\t" and create a String array.
2. Split that array into sub-arrays of 1 table heading per sub-array
3. Then, start reading the next line of the table, and for each sub-array, add the corresponding values from the columns.

请问这个计划听起来正确的还是我的事情过于复杂/被完全错了吗？是否有更简单的方法来做到这一点？ （前提是我仍然不知道如何将数组拆分成子阵，以及如何填充从表中的值的子阵）

Does this plan sound right or am I overcomplicating things/being completely wrong? Is there an easier way to do it? (provided that I still don't know how to split arrays into subarrays and how to populate the subarrays with the values from the table)

推荐答案

我会强烈建议你用一个读平面文件解析库对于这一点，就像优秀的 OpenCSV 。

I would strongly suggest you use a read flat file parsing library for this, like the excellent OpenCSV.

如果做不到这一点，这里是Java 8的解决方案。

Failing that, here is a solution in Java 8.

首先，创建一个类来重新present您的数据：

First, create a class to represent your data:

static class Bean {

    private final int id;
    private final String name;
    private final List<Integer> types;

    public Bean(int id, String name, List<Integer> types) {
        this.id = id;
        this.name = name;
        this.types = types;
    }

    //getters 

}

您使用各种清单的建议是基于非常脚本。 Java是面向对象的，所以你应该用它来你的优势。

Your suggestion to use various lists is very scripting based. Java is OO so you should use that to your advantage.

现在，我们只需要分析该文件：

Now we just need to parse the file:

public static void main(final String[] args) throws Exception {
    final Path path = Paths.get("path", "to", "file.tsv");
    final List<Bean> parsed;
    try (final Stream<String> lines = Files.lines(path)) {
        parsed = lines.skip(1).map(line -> line.split("\\s*\\|\\s*")).map(line -> {
            final int id = Integer.parseInt(line[0]);
            final String name = line[1];
            final List<Integer> types = Arrays.stream(line).
                    skip(2).map(t -> Integer.parseInt(t.replaceAll("\\D", ""))).
                    collect(Collectors.toList());
            return new Bean(id, name, types);
        }).collect(Collectors.toList());
    }
}

在本质上code，然后跳过第一行遍历文件中的行和每行：

In essence the code skips the first line then loops over lines in the file and for each line:

1. 分割上的分隔符行了 - 似乎是 | 。这就需要正则表达式，所以你需要躲避管，因为它是一个特殊字符。此外，我们分隔符后/前消耗任何空间。


2. 创建一个新的Bean 通过解析数组元素的每一行。


3. 首先解析ID给 INT


4. 下一步获取名称


5. 最后得到的线条的流，跳过前两个元素，并解析其余为列表＆LT;整数GT;

1. Split the line on the delimiter - seems to be |. This requires regex so you need to escape the pipe as it is a special character. Also we consume any spaces before/after the delimiter.
2. Create a new Bean for each line by parsing the array elements.
3. First parse the id to an int
4. Next get the name
5. Finally get a Stream of the lines, skip the first two elements, and parse the remaining to a List<Integer>

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