正在尝试在Java中将Unix命令的输出作为字符串返回...没有得到预期的结果

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class UnixCommandExecutor {
    public static String executeCommand(String command) {
        StringBuilder output = new StringBuilder();

        try {
            ProcessBuilder processBuilder = new ProcessBuilder();
            processBuilder.command("bash", "-c", command);

            Process process = processBuilder.start();

            // 读取命令的输出
            InputStream inputStream = process.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));

            String line;
            while ((line = reader.readLine()) != null) {
                output.append(line).append("\n");
            }

            // 等待命令执行完成
            int exitCode = process.waitFor();
            if (exitCode != 0) {
                // 命令执行失败
                throw new RuntimeException("Command execution failed with exit code: " + exitCode);
            }

        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }

        return output.toString();
    }

    public static void main(String[] args) {
        String command = "ls -l";
        String output = executeCommand(command);
        System.out.println(output);
    }
}