java - 与 Java : How to import an arbitrary . csv 文件中的文件实例函数混淆到 mysql 而不是特定文件？

Question

我目前已经有了将特定 .csv 文件(提供的目录)导入 mysql 的代码。

我正在尝试调整它并尝试使用 java 教程中演示的 create File() 方法，即。 File file = new File("d:\\myproject\\java\\Hello.java");并修改代码如下:

我的代码如图:

import java.sql.Connection;

import java.sql.Statement;
import java.io.*;

public class ImportCsv {

    public static void main(String[] args) {
        ImportCsv.readCsvUsingLoad();
    }

    public static void readCsvUsingLoad() {

        try (Connection connection = DBConnection.getConnection()) {

            File file = new File("C:/Users/User/Desktop/Test/upload2.csv");

            String loadQuery = "LOAD DATA LOCAL INFILE '" + "file" + "' INTO TABLE txn_tbl FIELDS TERMINATED BY ','"
                    + " LINES TERMINATED BY '\n'  " + "IGNORE 1 LINES(txn_amount, card_number, terminal_id)";
            System.out.println(loadQuery);
            Statement stmt = connection.createStatement();
            stmt.execute(loadQuery);
            System.out.println("Data import success");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

但是，Intellij 不断抛出 FileNotFoundException。

我是不是误解了这里创建文件实例的用法？

Answer 1

因为您使用文件名作为字符串 "file" 而不是您必须删除两个引号，并且您不需要创建文件，您只需要 路径(字符串):

String file = "C:/Users/User/Desktop/Test/upload2.csv";

String loadQuery = "LOAD DATA LOCAL INFILE '" + file + "' "
        //---------------------------------------^^
        + "INTO TABLE txn_tbl FIELDS TERMINATED BY ',' "
        + "LINES TERMINATED BY '\n'  " 
        + "IGNORE 1 LINES(txn_amount, card_number, terminal_id)";

---

您可以像这样使用 getAbsolutePath 的另一种方法:

File file = new File("C:/Users/User/Desktop/Test/upload2.csv");
String path = file.getAbsolutePath();

String loadQuery = "LOAD DATA LOCAL INFILE '" + path + "' "
        //---------------------------------------^^
        + "INTO TABLE txn_tbl FIELDS TERMINATED BY ',' "
        + "LINES TERMINATED BY '\n'  "
        + "IGNORE 1 LINES(txn_amount, card_number, terminal_id)";