java调用linux命令 返回值

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class ExecuteCommand {
    public static void main(String[] args) {
        try {
            ProcessBuilder pb = new ProcessBuilder("ls", "-l");
            Process process = pb.start();

            int exitCode = process.waitFor();
            System.out.println("Command exited with code " + exitCode);

            BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}