while (scanner.hasNextLine()) { String line = scanner.nextLine(); String[] values = line.split(","); model.addRow(values);}每行是什么意思

这段代码片段是在使用Java语言操作表格数据时，循环读取控制台输入的每一行数据，将每行数据使用逗号分隔符拆分成一个字符串数组，然后将该字符串数组添加为表格的一行数据。具体解释如下：

- `scanner.hasNextLine()` 判断控制台输入是否还有下一行数据。
- `String line = scanner.nextLine();` 读取控制台输入的一行数据。
- `String[] values = line.split(",");` 使用逗号分隔符拆分这行数据，得到一个字符串数组。
- `model.addRow(values);` 将该字符串数组添加为表格的一行数据。这里的 `model` 是指表格数据模型，通过调用 `addRow()` 方法可以向表格添加一行数据。

相关问题

private void readIntegersFromFile(File file) throws FileNotFoundException { Scanner scanner = new Scanner(file); if (model.getColumnCount() == 0) { String line = scanner.nextLine(); String[] values = line.split(","); model.setColumnCount(values.length); } while (scanner.hasNextLine()) { String line = scanner.nextLine(); String[] values = line.split(","); model.addRow(values); } scanner.close(); }请每行详细注释

好的，以下是对每行代码的详细注释：

private void readIntegersFromFile(File file) throws FileNotFoundException {

这是一个私有方法，用于从文件中读取整数，并将其填充到表格中。参数 `file` 是要读取的文件对象，方法声明了 `FileNotFoundException` 异常，表示在文件不存在时会抛出该异常。

Scanner scanner = new Scanner(file);

创建一个 `Scanner` 对象 `scanner`，并将要读取的文件对象 `file` 作为参数传入。

if (model.getColumnCount() == 0) {
    String line = scanner.nextLine(); 
    String[] values = line.split(",");
    model.setColumnCount(values.length);
}

判断表格（`model`）的列数是否为 0，如果是 0，则读取文件的第一行，并将其按逗号分隔成字符串数组 `values`，数组的长度就是列数。然后使用 `setColumnCount()` 方法设置表格的列数，即将表格的列数设置为 `values` 数组的长度。

while (scanner.hasNextLine()) {
    String line = scanner.nextLine();
    String[] values = line.split(",");
    model.addRow(values);
}

使用 `while` 循环读取文件中的每一行，将其按逗号分隔成字符串数组 `values`，然后使用 `addRow()` 方法将这些字符串添加到表格的新行中。

scanner.close();

关闭 `Scanner` 对象 `scanner`，避免资源泄漏。

Write java code: Copy the files, small_weapons.txt, and large_weapons.txt from the assignment folder on Blackboard and save them to your folder. For testing purposes, you should use the small file. Use the large file when you think the application works correctly. To see what is in the files use a text editor. Nilesh is currently enjoying the action RPG game Torchlight 2 which is an awesome game and totally blows Auction House Simulator 3, oh sorry, that should be Diablo 3, out of the water. He has got a file containing info on some of the unique weapons in the game. The transaction file contains the following information: Weapon Name (string) Weapon Type (string) Damage (int) Weapon Speed (double) … To tell if one weapon is better than another you need to know the Damage Per Second (DPS) the weapon does, since weapons have a different attack speed. DPS is calculated by taking the damage value and dividing it by the attack speed.a) You will write a program that will allow Nilesh to load the file and display the weapon info and DPS of every weapon in the input file. When the user chooses to open a weapon file, they are required to type in the filename. It will then read the 4 values about a particular weapon and then display the 4 values to the console window on one line neatly padded along with the DPS of the weapon. This is repeated until the end of the file. b) Modify your code from a) so that the weapon information written to the console window is also written to a text file. The user should be able to specify the name of the file. Add a header to the beginning of the file which has column headers for each column. At the end of the text file display the total number of weapons in the file. c) Document your code appropriately and add your name and id number as comments at the top of your code. Please also submit this text file you have created. Enter the file you want to search end with .txt: large_weapons.txt 1 Blackfang Bludgeon Great Hammer 489 1.44 339.58333333333337 2 Bones 2 Boneshredder Great Axe 256 0.84 304.76190476190476 3 Comet's Tail Great Sword 872 1.2 726.6666666666667 4 Decapitator Great Sword 188 1.08 174.07407407407408 5 Demolisher Great Hammer 887 1.32 671.9696969696969

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

public class WeaponInfo {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter the file you want to search end with .txt: ");
        String fileName = scanner.nextLine();
        File file = new File(fileName);

        try {
            Scanner fileScanner = new Scanner(file);
            FileWriter writer = new FileWriter(new File("weapon_info_output.txt"));
            writer.write("Weapon Name\tWeapon Type\tDamage\tWeapon Speed\tDPS\n");
            int count = 0;
            while (fileScanner.hasNextLine()) {
                String line = fileScanner.nextLine();
                String[] tokens = line.split(" ");
                String weaponName = tokens[0];
                String weaponType = tokens[1];
                int damage = Integer.parseInt(tokens[2]);
                double weaponSpeed = Double.parseDouble(tokens[3]);
                double dps = damage / weaponSpeed;
                System.out.printf("%-20s%-20s%-10d%-15.2f%.2f\n", weaponName, weaponType, damage, weaponSpeed, dps);
                writer.write(weaponName + "\t" + weaponType + "\t" + damage + "\t" + weaponSpeed + "\t" + dps + "\n");
                count++;
            }
            System.out.println("Total number of weapons: " + count);
            writer.write("Total number of weapons: " + count);
            writer.close();
            fileScanner.close();
        } catch (IOException e) {
            System.out.println("Unable to read file: " + fileName);
        } catch (NumberFormatException e) {
            System.out.println("Invalid file format: " + fileName);
        }
        scanner.close();
    }
}