Java Runtime.getRuntime().exec 不同的输出格式

Question

我有一个简单的Python程序(hw1.py)如下:

x = int(input("Enter x value: "))
y = int(input("Enter y value: "))

print("x is " + str(x))
print("y is " + str(y))
print("Output is " + str(x+y))

当我从终端运行它时，我按预期得到以下输出:

Enter x value: 10
Enter y value: 20
x is 10
y is 20
Output is 30

但是，当我从 Java 运行它并提供输入(“10”和“20”)时，我得到的输出略有不同。以下是编译和运行 python 文件的 Java 代码:

String osName = System.getProperty("os.name").toLowerCase();
boolean isMacOs = osName.startsWith("mac os x");
String macPythonPath = "/Library/Frameworks/Python.framework/Versions/3.6/bin/python3";
String unixPythonPath = "/usr/bin/python3";
Process p;
if (isMacOs) {
    p = Runtime.getRuntime().exec(macPythonPath + " -m py_compile " + "/Users/inanc/Desktop/pythonDocs/hw1.py");

} else {
    p = Runtime.getRuntime().exec(unixPythonPath + " -m py_compile " + "/Users/inanc/Desktop/pythonDocs/hw31.py");  
}

BufferedReader stdError = new BufferedReader(new 
        InputStreamReader(p.getErrorStream()));


String resError = "", s;
// read any errors from the attempted command
while ((s = stdError.readLine()) != null) {
    resError = resError + s + "\n";
}
resError = resError.trim();
stdError.close();

if (resError.equals("")) {

    if (isMacOs) {
        p = Runtime.getRuntime().exec(macPythonPath + " " + "/Users/inanc/Desktop/pythonDocs/hw1.py");

    } else {
        p = Runtime.getRuntime().exec(unixPythonPath + " " + "/Users/inanc/Desktop/pythonDocs/hw1.py"); 
    }
    String[] inputs = {"10", "20"};
    OutputStream out = p.getOutputStream();
    for (String input: inputs) {
        if (input.equals("") == false)
            out.write((input+"\n").getBytes());
    }
    out.flush();

    BufferedReader stdInput = new BufferedReader(new 
            InputStreamReader(p.getInputStream()));

    stdError = new BufferedReader(new 
            InputStreamReader(p.getErrorStream()));

    // read the output from the command
    String res = ""; 
    s = null;
    while ((s = stdInput.readLine()) != null) {
        res = res + s + "\n" ;
    }
    res = res.trim();

    resError = "";
    // read any errors from the attempted command
    while ((s = stdError.readLine()) != null) {
        resError = resError + s + "\n";
    }
    resError = resError.trim();
    stdInput.close();
    stdError.close();
    p = null;
    System.out.println(res);
} else {
    System.err.println(resError);
}

调用此代码后，输出如下:

Enter x value: Enter y value: x is 10
y is 20
Output is 30

如何通过终端执行获得完全相同的输出？至少我想在输入输入后保留换行符。

Answer 1

只有当你编写程序时，才有一种方法，将参数 10 写入进程，然后从进程中读取下一行，然后将 20 写入进程，然后从进程中读取另一行，依此类推

然而，在您的代码中，您在单个循环中编写流程所需的所有输入