java模拟用户对外部程序输入

import java.util.Scanner;

public class UserInputSimulation {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入数据：");
        String input = scanner.nextLine();
        System.out.println("用户输入的数据是：" + input);
    }
}

public class UserInputSimulation {
    public static void main(String[] args) {
        if (args.length > 0) {
            String input = args[0];
            System.out.println("用户输入的数据是：" + input);
        } else {
            System.out.println("请传入数据作为命令行参数");
        }
    }
}

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class UserInputSimulation {
    public static void main(String[] args) {
        try (BufferedReader reader = new BufferedReader(new FileReader("input.txt"))) {
            String input = reader.readLine();
            System.out.println("用户输入的数据是：" + input);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}