java执行cmd命令

• 参考1
• 参考2
• 参考3
• cmd命令参考
• ProcessBuilder
• ProcessBuilder 和 Process

/**
 * <p>
 * <a href="https://www.cnblogs.com/convict/p/15892263.html">参考1</a>
 * <a href="https://www.cnblogs.com/youmiyou/p/15779230.html">参考2</a>
 * <a href="https://www.jianshu.com/p/43ce90abb5cd">参考3</a>
 * <a href="https://www.jb51.net/article/57637.htm">cmd命令参考</a>
 * <a href="https://blog.youkuaiyun.com/zhoujing_0424/article/details/79917368">ProcessBuilder</a>
 * <a href="https://blog.youkuaiyun.com/u013256816/article/details/54603910">ProcessBuilder 和 Process</a>
 * </p>
 *
 * @author 醉瑾
 * @since 2022-07-28
 */
public class Test8 {
    public static void execCommand() {
        try {
            Runtime runtime = Runtime.getRuntime();
            // 打开任务管理器，exec方法调用后返回 Process 进程对象
            Process process = runtime.exec("cmd.exe /c start diskmgmt.msc");
            // 等待进程对象执行完成，并返回“退出值”，0 为正常，其他为异常
            int exitValue = process.waitFor();
            System.out.println("exitValue: " + exitValue);
            // 销毁process对象
            process.destroy();
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void execCommandAndGetOutput() {
        try {
            Runtime runtime = Runtime.getRuntime();
            Process process = runtime.exec("cmd.exe /c netstat -aon|findstr 3306");
            // 输出结果，必须写在 waitFor 之前
            String outStr = getStreamStr(process.getInputStream());
            // 错误结果，必须写在 waitFor 之前
            String errStr = getStreamStr(process.getErrorStream());
            int exitValue = process.waitFor(); // 退出值 0 为正常，其他为异常
            System.out.println("exitValue: \n" + exitValue);
            System.out.println("outStr: \n" + outStr);
            System.out.println("errStr: \n" + errStr);
            process.destroy();
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void execute(String cmd) {
        BufferedReader br = null;
        try {
            File file = new File(System.getProperty("user.dir"));
            File tmpFile = new File(System.getProperty("user.dir") + "\\temp.tmp");//新建一个用来存储结果的缓存文件
            if (!file.exists()) {
                file.mkdirs();
            }
            if (!tmpFile.exists()) {
                tmpFile.createNewFile();
            }

            ProcessBuilder pb = new ProcessBuilder().command("cmd.exe", "/c", cmd).inheritIO();
            pb.redirectErrorStream(true);//这里是把控制台中的红字变成了黑字，用通常的方法其实获取不到，控制台的结果是pb.start()方法内部输出的。
            pb.redirectOutput(tmpFile);//把执行结果输出。
            pb.start().waitFor();//等待语句执行完成，否则可能会读不到结果。

            InputStream in = new FileInputStream(tmpFile);
            br = new BufferedReader(new InputStreamReader(in, "GBK"));
            String line;
            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }
            br.close();
            br = null;
            tmpFile.delete();// 卸磨杀驴,删除刚才的临时文件
            System.out.println("执行完成");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    public static String getStreamStr(InputStream is) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(is, "GBK"));
        StringBuilder sb = new StringBuilder();
        String line;
        while ((line = br.readLine()) != null) {
            sb.append(line);
            sb.append("\n");
        }
        br.close();
        return sb.toString();
    }

    public static void main(String[] args) {
        execCommand();
//        execCommandAndGetOutput();
//        execute("ping www.baidu.com");
    }
}