在新進程上啟動cmd.exe，然后在其上啟動用戶掃描儀

Question

有沒有一種方法可以通過ProcessBuilder打開cmd.exe ，然后引用其流，以便可以調用NewProcessOutputStream.println()和Scanner s = new Scanner(NewProcessInputStream) ？

我知道我可以發出諸如cmd /c dir類的命令並讀取輸入流，但是我想打開cmd進程，然后訪問其流，以便可以在任何時候打印到它。

我在想什么可能嗎？ 還是應該通過該過程執行另一個程序？

編輯（更新）：輸出不符合預期

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();
    }
}

輸出：

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，你可以用獲得的過程輸入Process.getOutputStream()並使用其輸出Process.getInputStream()

這是一個例子：

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();
    }

}