Question

我想编写一个程序，可以打印和修改不规则的csv文件。格式如下：

    1.date
    2.organization name
    3. student name, id number, residence
       student name, id number, residence
       student name, id number, residence
       student name, id number, residence
       student name, id number, residence
    1.another date
    2.another organization name
    3. student name, id number, residence
       student name, id number, residence
       student name, id number, residence
      ..........

例如，数据可以如下给出：

1. 10/09/2016
2. cycling club
3. sam, 1000, oklahoma
   henry, 1001, california
   bill, 1002, NY
1. 11/15/2016
2. swimming club
3. jane, 9001, georgia
   elizabeth, 9002, lousiana

我是初学者，我没有在网上找到任何可行的资源来处理这类问题。我主要担心的是，我们如何迭代循环并确定俱乐部的日期和名称，并将它们送入阵列？请指教。

Answer 1

我认为这应该对你有所帮助。基本上你的混乱csv应该有一些模式。下面是我的代码来安排你的csv

   public static void main(String[] args) throws FileNotFoundException, UnsupportedEncodingException {

        PrintWriter writer = new PrintWriter("file.txt", "UTF-8");
            try{

              //Create object of FileReader
              FileReader inputFile = new FileReader("csv.txt");

              //Instantiate the BufferedReader Class
              BufferedReader bufferReader = new BufferedReader(inputFile);

              //Variable to hold the one line data
              String line;
              String date="";String org ="";String student ="";
              // Read file line by line and print on the console
              while ((line = bufferReader.readLine()) != null)   {
                  if(line.contains("1.")){
                      if(date!="" || org!=""){
                          writer.println(date+","+org+","+student);
                          student ="";
                       }
                         date = line.substring(2);
                        }else if(line.contains("2.")){
                            org = line.substring(2);

                      }else{
                            line = "("+line+")";
                          student += line+",";
                  }

                    System.out.println(line);
              }
              writer.println(date+","+org+","+student);
              //Close the buffer reader
              bufferReader.close();
      }catch(Exception e){
        System.out.println("Error while reading file line by line:" + e.getMessage());                      
   }
       writer.close();
  }

这是您将获得的输出

   10/09/2016, cycling club,(3. sam, 1000, oklahoma),(   henry, 1001, california),(   bill, 1002, NY),
   11/15/2016, swimming club,(3. jane, 9001, georgia),(   elizabeth, 9002, lousiana),

我正在从csv.txt读取文件。 while循环遍历文本文件的每一行。所有字段都存储在变量中。当下一个日期到来时，我将所有这些写入输出文件。在while循环终止后，csv的最后一行被写入文件。

Answer 2

尝试uniVocity-parsers来处理此问题。要解析此类格式，您需要找到一些示例here。要写作，请查看here和here。

根据我给出的例子，你可以写：

final ObjectRowListProcessor dateProcessor = new ObjectRowListProcessor();
final ObjectRowListProcessor clubProcessor = new ObjectRowListProcessor();
final ObjectRowListProcessor memberProcessor = new ObjectRowListProcessor();

InputValueSwitch switch = new InputValueSwitch(0){
    public void rowProcessorSwitched(RowProcessor from, RowProcessor to) {
    //your custom logic here
    if (to == dateProcessor) {
        //processing dates.
    }
    if (to == clubProcessor) {
        //processing clubs.
    }
    if (to == memberProcessor){
        //processing members
    }
};

switch.addSwitchForValue("1.", dateProcessor, 1);  //getting values of column 1 and sending them to `dateProcessor`
switch.addSwitchForValue("2.", clubProcessor, 1); //getting values of column 1 and sending them to `clubProcessor`
switch.addSwitchForValue("3.", memberProcessor, 1, 2, 3); //getting values of columns 1, 2, and 3 and sending them to `memberProcessor` 
setDefaultSwitch(memberProcessor, 1, 2, 3); //Rows with blank value at column 0 are members. Also get columns 1, 2, and 3 and send them to `memberProcessor`

CsvParserSettings settings = new CsvParserSettings(); //many options here, check the tutorial and examples

// configure the parser to use the switch
settings.setRowProcessor(switch);

//creates a parser
CsvParser parser = new CsvParser(settings);

//parse everying. Rows will be sent to the RowProcessor of each switch, depending on the value at column 0.
parser.parse(new File("/path/to/file.csv"));

免责声明：我是这个图书馆的作者，它是开源和免费的（Apache 2.0许可证）

在java中修改复杂的csv文件

2 个答案: