Question

我在学期开始之前练习Java，并且我尝试创建将在指定的CSV文件中读取的代码，并使用它创建数据库。但我收到的错误是

＆＃34;线程中的异常＆＃34; main＆＃34; java.lang.ArrayIndexOutOfBoundsException：3
在LoadData.main（LoadKids.java:52）＆＃34;

我的代码如下所示。
错误在这一行＆＃34;评级=字段[3] .trim（）;＆＃34;

import java.io.File;
import java.io.FileNotFoundException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;


public class LoadData {

public static void main(String[] args) {
    Connection c = null;
    Statement s = null;
    Scanner fromFile = null;
    String sql1 = null, sql2 = null;
    String line = null, ID = null, Console = null, Title = null, Rating = null, Multiplayer = null;
    String[ ] fields;

    try {
        // Define Connection and Statement objects.
        Class.forName("org.sqlite.JDBC");
        c = DriverManager.getConnection("jdbc:sqlite:games.db");
        s = c.createStatement();

        // Instantiate scanner to read from file.
        fromFile = new Scanner(new File ("FileName.csv"));

        // Create the table.
        sql1 = "create table if not exists " +
            "games(gameid integer, " +
            "ID varchar(2), " +
            "Console varchar(15), " +
            "Title varchar(20), " +
            "Rating varchar(2), " +
            "Multiplayer varchar(3));";
        System.out.println("sql1: " + sql1);
        s.executeUpdate(sql1);

        // Read and throw away header line.
        fromFile.nextLine( );

        // Populate the table.
        for (int id = 1001; fromFile.hasNextLine( ); id++) {
            line = fromFile.nextLine( );
            fields = line.split(" ");
            ID = fields[0].trim();
            Console = fields[1].trim();
            Title = fields[2].trim();
            Rating = fields[3].trim();
            Multiplayer = fields[4].trim();
            sql2 = String.format(
                "insert into games (gameid, ID, Console, Title, Rating, Multiplayer) " +
                "values (%d, '%s', '%s', '%s', '%s', '%s');", 
                id, ID, Console, Title, Rating, Multiplayer);
            System.out.println(sql2);
            s.executeUpdate(sql2);
        }
        c.close( );
    }
    catch (FileNotFoundException e) {
        System.out.println("File queries.sql not found.");
        System.err.println( e.getClass().getName() + 
            ": " + e.getMessage() );
    }
    catch(SQLException e) {
        System.out.println("SQLException.");
        System.err.println( e.getClass().getName() + 
            ": " + e.getMessage() );
    }
    catch (ClassNotFoundException e ) {
        System.err.println( e.getClass().getName() + 
            ": " + e.getMessage() );
    }
    finally {
        fromFile.close( );
    }
}
}

Answer 1

请将数据发布到csv文件中。通常，CSV文件以逗号分隔，因此名称以逗号分隔值。但是，您的代码使用空格来分隔值。

fields = line.split(" ");

如果您的CSV数据实际上以逗号分隔，请将该行更改为

fields = line.split(",");

如果您的CSV数据以空格分隔，请确认文件中每行至少有5个以空格分隔的项目。

Java - 超出界限异常数据库

1 个答案: