如何在Java中进行文本处理

Question

我有一个CSV文件

 input.csv
    1,[103.85,1.28992],[103.89,1.294],[103.83,1.216]
    2,[103.5,1.292],[103.9,1.4],[103.3,1.21]
    3,[103.6,1.291],[103.6,1.39],[103.3,1.29]

由此我需要将其转换为

{
                    "type": "LineString",
                    "coordinates": [[103.85,1.28992],[103.89,1.294],[103.83,1.216]]

                "properties": {
                    "id": "1"
                }
            },
            {
                "type": "LineString",
                "properties": {
                    "id": "2"
                },
                "coordinates": [[103.5,1.292],[103.9,1.4],[103.3,1.21]]

        },{
                "type": "LineString",
                "properties": {
                    "id": "3"
                },
                "coordinates": [[103.6,1.291],[103.6,1.39],[103.3,1.29]]

        }

我现在正在尝试在Java中进行操作。因此，我读了带有open csv

的CSV文件

try (CSVReader reader = new CSVReader(new FileReader(fileName))) {
            String[] nextLine;
            while ((nextLine = reader.readNext()) != null) {
                for (String e: nextLine) {
                   // System.out.format("%s ", e);
                System.out.println( e.split(",",1));
                }
            }

，但是我在拼凑行时有问题。如果您看第一行，我想拥有 1作为一部分，其余的 [103.85,1.28992],[103.89,1.294],[103.83,1.216]作为另一部分。所以我可以构建字符串

  String s="{"type": "LineString", "coordinates": "+s[1]+"
     "properties": { "id":"+s[0]+"} }";

任何帮助都将受到赞赏

Answer 1

您可以尝试：

(d+),(.*)

您不需要拆分...如果执行它，您会得到两个组。第1组是数字，第2组是后面的内容说明

尝试此样本：

final String regex = "(\d+),(.*)";
final String string = "1,[103.85,1.28992],[103.89,1.294],[103.83,1.216]n"
     + "2,[103.5,1.292],[103.9,1.4],[103.3,1.21]n"
     + "3,[103.6,1.291],[103.6,1.39],[103.3,1.29]";
final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE);
final Matcher matcher = pattern.matcher(string);
while (matcher.find()) {
    System.out.println(matcher.group(1));
    System.out.println(matcher.group(2));
}

Answer 2

使用jsonsimple创建所需的JSON。我认为最简单的JSON LIB。请参阅此使用示例。

Answer 3

您可以自己解析行：

try (BufferedReader reader = new BufferedReader(new FileReader(fileName))) {
    String nextLine;
    while ((nextLine = reader.readLine()) != null) {
        int ix = nextLine.indexOf(',');
        if (ix >= 0) {
            String head = nextLine.substring(0, ix);
            String tail = nextLine.substring(ix+1);
            doSomethingWith(head, tail);
        }
    }
}

Answer 4

问题是要以所需的方式获取数据，以生成input.csv文件以将不同的部分封装在引号中。

所以

input.csv
   1,"[103.85,1.28992],[103.89,1.294],[103.83,1.216]"
   2,"[103.5,1.292],[103.9,1.4],[103.3,1.21]"
   3,"[103.6,1.291],[103.6,1.39],[103.3,1.29]"

或

input.csv
   "1","[103.85,1.28992],[103.89,1.294],[103.83,1.216]"
   "2","[103.5,1.292],[103.9,1.4],[103.3,1.21]"
   "3","[103.6,1.291],[103.6,1.39],[103.3,1.29]"

因为它是在一条线和线的末端之间的六个逗号，任何CSV解析器都会解释该行有七个列而不是两列。