java - 如何从 Java arraylist 中删除空的 csv 记录？

Question

我有一个要求，我需要获取一些值，然后将所有这些值写入 csv 文件。为此，我将值添加到 Java Arraylist 并写入 csv 文件。但是当我这样做时，它会将记录写入 CSV，但记录之间有空行。不确定为什么会出现此问题。

1,abc,fname,lname,email,log


1,abc1,fname1,lname1,email1,log1
1,abc2,fname2,lname2,email2,log2


1,abc3,fname3,lname3,email3,log3
1,abc4,fname4,lname4,email4,log4

这是我的代码。请告诉我这段代码有什么问题:

public StringBuilder fetchUsers() {
    ArrayList<String> users = null;
    StringBuilder sb1 = new StringBuilder();
    try {
        client = getMyClient();
        if (client != null) {
            UserList usersList = getUsers();
            if (usersList.totalCount != 0 && usersList.totalCount >= 1) {
                System.out.println("usersList.totalCount ----->"
                        + usersList.totalCount);

                for (KalturaUser user : usersList.objects) {
                    users = new ArrayList<String>();
                    if (user != null) {
                        String action = null;
                        String userFullName = null;
                        String modifiedName = null;
                        String firstName = user.firstName;
                        if (user.id != null) {
                            String cnum = getUserUniqueId(user.id);
                            String userRole = getUserRole(user.id);
                            if (cnum != null || userRole != null) {
                                action = validateCnum(cnum, userRole);
                                if (!action.equals("3")) {
                                    users.add(action);
                                    users.add(cnum);
                                    if (firstName != null
                                            && firstName.contains("@")) {
                                        user.email = firstName;
                                        userFullName = getUserNames(user.id);
                                        firstName = userFullName;
                                    }
                                    users.add(firstName);
                                    users.add(user.lastName);
                                    users.add(user.email);
                                    users.add(userRole);
                                }
                            }
                        }
                    }
                    allUsers.add(users);
                }
            }
        }
    } catch (MyException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ParserConfigurationException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (SAXException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    writeToCSV();
    return sb1;
}


private void writeToCSV() {
    FileWriter fileWriter = null;
    CSVPrinter csvFilePrinter = null;
    CSVFormat csvFileFormat = CSVFormat.DEFAULT.withRecordSeparator(System
            .getProperty("line.separator"));
    try {
        fileWriter = new FileWriter("C:/users.csv");
        csvFilePrinter = new CSVPrinter(fileWriter, csvFileFormat);
        csvFilePrinter.printRecord(USER_COLUMNS);
        for (List<String> rowData : allUsers) {
            csvFilePrinter.printRecord(rowData);
        }
    } catch (Exception e) {
        logger.error(e.getStackTrace());
    } finally {
        try {
            fileWriter.flush();
            fileWriter.close();
            csvFilePrinter.close();
        } catch (IOException e) {
            logger.error("Error while flushing/closing fileWriter/csvPrinter!");
            }
    }
}

Answer 1

这个:

 allUsers.add(users);

应该在 if (user != null) 和所有子 ifs 中

像这样:

if (user != null) {
...
    if (user.id != null) {

        ...
        if (cnum != null || userRole != null) {
            ....
            if (!action.equals("3")) {
                users = new ArrayList<String>();
                ....
                allUsers.add(users);
            }
        }
    }
}

一般来说，只有当你有东西要添加时，你才应该创建数组并将它添加到 allUsers