java - 从 .csv 列字段中删除逗号并导入到数据库

Question

下面的类会将 .csv 导入数据库表。它工作正常。但是当它遇到像2,345这样的数值时。这会导致错误。

在我的 .csv 文件中，有 3 列，如下所示:

db2 表“COMPUTER”中这些列的数据类型为 COL_A(VArchar 50)、COL_B(Double)、COL_C(Varchar 50)

COL_A | COL_B | COL_C

<小时/>

KKGG56 | 7,567 | 7,567 2013年6月

GGHHK2 | 259,024 | 259,024 2012 年 5 月

那么，如何在导入数据库表时从特定列中删除这些逗号以及将代码放置在程序中的何处？请帮忙。

public class CSVLoader {

private static final 
    String SQL_INSERT = "INSERT INTO OPM.${table}
         (${keys})      VALUES(${values})";

private static final String TABLE_REGEX = "\\$\\{table\\}";

private static final String KEYS_REGEX = "\\$\\{keys\\}";

private static final String VALUES_REGEX = "\\$\\{values\\}";

private Connection connection;

private char seprator;

public CSVLoader(Connection connection) {

    this.connection = connection;

    //Set default separator

    this.seprator = ',';
}

      public void loadCSV(String csvFile, String tableName) throws Exception {

    CSVReader csvReader = null;

    if(null == this.connection) {

        throw new Exception("Not a valid connection.");
    }

    try {

        csvReader = new CSVReader(new FileReader(csvFile), this.seprator);

    } catch (Exception e) {

        e.printStackTrace();

        throw new Exception("Error occured while executing file. "

                   + e.getMessage());

              }

        String[] headerRow = csvReader.readNext();

    if (null == headerRow) {

        throw new FileNotFoundException(


                        "No columns defined in given CSV file." +

                         "Please check the CSV file format.");
    }

    String questionmarks = StringUtils.repeat("?,", headerRow.length);

    questionmarks = (String) questionmarks.subSequence(0, questionmarks

            .length() - 1);


    String query = SQL_INSERT.replaceFirst(TABLE_REGEX, tableName);

    query = query
            .replaceFirst(KEYS_REGEX, StringUtils.join

             (headerRow,   ","));

    query = query.replaceFirst(VALUES_REGEX, questionmarks);

            System.out.println("Query: " + query);

    String[] nextLine;

    Connection con = null;

    PreparedStatement ps = null;

    try {
        con = this.connection;

        con.setAutoCommit(false);

        ps = con.prepareStatement(query);

                       final int batchSize = 1000;

                     int count = 0;

        Date date = null;

        while ((nextLine = csvReader.readNext()) != null) {

            System.out.println( "inside while" );

            if (null != nextLine) {

                int index = 1;

                for (String string : nextLine) {

                    date = DateUtil.convertToDate(string);

        if (null != date) {

                    ps.setDate(index++, new java.sql.Date(date

                    .getTime()));

                     } else {

                  ps.setString(index++, string);

    System.out.println( "string" +string);

                    }

                }

                ps.addBatch();

            }

            if (++count % batchSize == 0) {

                ps.executeBatch();

            }

                     }


        ps.executeBatch(); // insert remaining records

        con.commit();

    } catch (Exception e) {

        con.rollback();

        e.printStackTrace();

        throw new Exception(

        "Error occured while loading data 

                from file                to                      database."

               + e.getMessage());

    } finally {

             if (null != ps)


            ps.close();

        if (null != con)

            con.close();

            System.out.println("csvReader will be closed");

        csvReader.close();

    }

}

public char getSeprator() {

    return seprator;

}

public void setSeprator(char seprator) {

    this.seprator = seprator;

}


         }

Answer 1

回答您的问题:
您必须使用 Double.parseDouble("2,345".replaceAll(",","")) 解析 CSV 文本，但必须调用 ps.setDouble()在数据库中存储 double 值，而不是 ps.setString()!

for (String string : nextLine) {
  date = DateUtil.convertToDate(string);

  if (null != date) {
    ps.setDate(index++, new java.sql.Date(date.getTime()));
  } 
  else {
     try {
       final double doubleValue = Double.parseDouble(string.replaceAll(",",""));

       ps.setDouble(index++, doubleValue);
     }
     catch(NumberFormatException e) {
       // For invalid double
       ps.setString(index++, string);
     }
  }

这段代码不太健壮，如果你在第三列中有日期或数字，你就会遇到麻烦!看着 https://stackoverflow.com/questions/18067934/parsing-csv-file-with-java/18068238#18068238要使用高级映射解决方案，您需要提前了解数据结构。