Question

有没有办法通过cmd.exe打开ProcessBuilder，然后引用其流，以便可以拨打NewProcessOutputStream.println()和Scanner s = new Scanner(NewProcessInputStream)？

我知道我可以发出cmd /c dir之类的命令并读取输入流，但我想打开cmd进程，然后访问其流，以便我可以打印到它每当。

我在想什么？或者我应该通过这个过程执行另一个程序吗？

编辑（更新）：输出不是预期的

import java.io.*;
import java.util.*;

public class Terminal {
    public static void main(String[] args) throws IOException {

        Process cmd = new ProcessBuilder("cmd").start();

        PrintWriter writer = new PrintWriter(cmd.getOutputStream());
        BufferedReader reader = new BufferedReader(new InputStreamReader(cmd.getInputStream()));

        writer.println("Hello");
        writer.println("World!");
        writer.println("How are you?");
        writer.close();

        String line;

        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }
        reader.close();
    }
}

输出：

C:\Users\Paul\Desktop\temp\CLI\src>java Terminal
Microsoft Windows [Version 10.0.15063]
(c) 2017 Microsoft Corporation. All rights reserved.

C:\Users\Paul\Desktop\temp\CLI\src>Hello

C:\Users\Paul\Desktop\temp\CLI\src>World!

C:\Users\Paul\Desktop\temp\CLI\src>How are you?

C:\Users\Paul\Desktop\temp\CLI\src>

C:\Users\Paul\Desktop\temp\CLI\src>

Answer 1

是的，您可以使用Process.getOutputStream()使用Process.getInputStream()获取流程输入。

以下是一个例子：

public class ProcessTest {

    public static void main(String[] args) throws IOException {
        Process grep = new ProcessBuilder("grep", "foo").start();

        PrintWriter writer = new PrintWriter(grep.getOutputStream());
        BufferedReader reader = new BufferedReader(new InputStreamReader(grep.getInputStream()));

        writer.println("this is the first line");
        writer.println("this is the foo line");
        writer.println("this is the last line");
        writer.println("nope, another foo");
        writer.close();

        // EDIT: fixed end of stream check
        String line = reader.readLine();
        while (line != null) {
            System.out.println(line);
            line = reader.readLine();
        }
        reader.close();
    }

}

在新进程上启动cmd.exe，然后在其上启动用户扫描程序

1 个答案: