Java 文件操作：使用字节流读写文件、字符串拼接和复制

以下是 Java 代码实现：

import java.io.*;

public class InputDemo { public static void main(String[] args) { // 第一步：循环随机输入三段字符串 String[] inputs = new String[3]; for (int i = 0; i < 3; i++) { System.out.println('请输入第' + (i+1) + '段字符串：'); BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); try { inputs[i] = reader.readLine(); } catch (IOException e) { e.printStackTrace(); } }

    // 第二步：将三段字符串拼接成一个字符串，并写入文件
    StringBuffer sb = new StringBuffer();
    for (String input : inputs) {
        sb.append(input);
    }
    String content = sb.toString();
    try {
        FileOutputStream fos = new FileOutputStream('c:\inputDemo.txt');
        fos.write(content.getBytes());
        fos.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

    // 第三步：读取文件内容并打印
    try {
        FileInputStream fis = new FileInputStream('c:\inputDemo.txt');
        byte[] buffer = new byte[1024];
        int len = 0;
        while ((len = fis.read(buffer)) != -1) {
            System.out.print(new String(buffer, 0, len));
        }
        fis.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

    // 第四步：将文件内容复制到另一个文件
    try {
        FileInputStream fis = new FileInputStream('c:\inputDemo.txt');
        FileOutputStream fos = new FileOutputStream('c:\inputDemo2.txt');
        byte[] buffer = new byte[1024];
        int len = 0;
        while ((len = fis.read(buffer)) != -1) {
            fos.write(buffer, 0, len);
        }
        fis.close();
        fos.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

}