ProcessBuilder.redirectOutput( myFile)不会立即更新文件，而是仅在刷新后更新

import java.io.File;
import java.io.IOException;

public class RedirectOutputExample {
    public static void main(String[] args) {
        ProcessBuilder processBuilder = new ProcessBuilder("echo", "Hello, World!");
        File outputFile = new File("output.txt");
        processBuilder.redirectOutput(outputFile);

        try {
            Process process = processBuilder.start();
            process.waitFor();

            // 手动刷新缓冲区
            process.getOutputStream().flush();

            System.out.println("文件已更新");
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }
}