在Runtime.getRuntime（）中传递文件名时出错exec（...）

Question

我试图从java程序中编译一个python文件。当我直接传递文件名时，它工作正常。但是当我尝试传递一个包含文件名的字符串时，我得到一个错误。 我需要传递一个包含文件名的字符串，因为我从另一个函数获取路径。我分割路径以获取文件名。任何人都可以帮助我实现这一目标？

看一看我所到目前为止已经试过：

import java.io.BufferedReader; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.io.OutputStream; 

public class Python_Compiler { 
    static String newName = null; 
    static String r2; 
    static String result; 
    public static void main(String args[]) throws IOException{ 
     InputStream inStream = null; 
     OutputStream outStream = null; 

     String filepath = "C:\\Hello.py"; 

      String p = filepath; 
      System.out.println(p); 
      int pos1 = p.lastIndexOf("\\"); 
      int pos2 = p.lastIndexOf(".py"); 
      result = p.substring(pos1+1, pos2); 
      r2 = p.substring(0,pos1); 
      System.out.println("PartialPath: "+r2+"\\"); 
      System.out.println("The file name only: "+result+".py"); 

     newName = filepath.replaceAll("(\\.\\S+?$)","1$1"); 
     File originalcopy =new File(newName); 

     inStream = new FileInputStream(filepath); 
     outStream = new FileOutputStream(originalcopy); 

     byte[] buffer = new byte[1024]; 

     int length; 
     //copy the file content in bytes 
     while ((length = inStream.read(buffer)) > 0){ 

      outStream.write(buffer, 0, length); 

     } 

     inStream.close(); 
     outStream.close(); 
     System.out.println("File is copied successful!"); 



     String ret = compile(); 
     System.out.println("Returned String from Inside Log: "+ret); 

     int counter = 0; 

     while(!ret.equals("Compilation Successful !!!") && counter!=50) 
     { 

      System.out.println("Your file contains errors"); 
      String myReturnedErrorDetails = Reggex_Capture.Extracter(ret); 
      System.out.println("My Returned Error Details: "+myReturnedErrorDetails); 
      String[] splitted = myReturnedErrorDetails.split(" "); 

      int lineNumber = Integer.parseInt(splitted[0]); 
      System.out.println("Line number: "+lineNumber); 
      System.out.println("Error: "+splitted[1]); 
      String theError = splitted[1]; 
      String myWholeSolution; 
      myWholeSolution = Fixer.PythonFix(theError); 
      String[] secondSplitted = myWholeSolution.split(" "); 
      String mySolution = secondSplitted[1]; 
      int myPercentage = Integer.parseInt(secondSplitted[0]); 
      System.out.println("The solution proposed by the fixer is: "+ mySolution); 
      System.out.println("The best percentage returned by the fixer is: "+myPercentage); 
      //Python_Replacer.fix(lineNumber,theError, filepath, mySolution); 
      Python_Replacer.fix(lineNumber,theError, newName, mySolution); 

      counter++; 
      ret = compile(); 


     } 



    } 
     public static String compile() 
     { 
      String log=""; 


      String myDirectory = r2; 

      try { 
       String s= null; 
       //change this string to your compilers location 
       // String fileName = "Hello1.py"; 
       Process p = Runtime.getRuntime().exec("cmd /C python result", null, new java.io.File(myDirectory)); 

      BufferedReader stdError = new BufferedReader(new 
        InputStreamReader(p.getErrorStream())); 
      boolean error=false; 

      log+=""; 
      while ((s = stdError.readLine()) != null) { 
       log+=s; 
       error=true; 
       //log+=""; 

      }if(error==false) log+="Compilation Successful !!!"; 


     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
      /*String log2 = log; 
      System.out.println("LOG2: "+log2); 
      Reggex_Capture.Extracter(log2);*/ 

      return log; 
     } 


     public int runProgram() 
     { 
      int ret = -1; 
      try 
      {    
       Runtime rt = Runtime.getRuntime(); 
       Process proc = rt.exec("cmd.exe /c start a.exe"); 
       proc.waitFor(); 
       ret = proc.exitValue(); 
      } catch (Throwable t) 
       { 
       t.printStackTrace(); 
       return ret; 
       } 
      return ret;      
     }} 

看一看错误：

C:\Hello.py 
PartialPath: C:\ 
The file name only: Hello.py 
File is copied successful! 
Returned String from Inside Log: python: can't open file 'result': [Errno 2] No such file or directory 
Your file contains errors 
Received String: python:#can't#open#file#'result':#[Errno#2]#No#such#file#or#directory 
Line Number: null 
Z atfer while: null 
Keywords: null 
Error details: null null 
My Returned Error Details: null null 
    Exception in thread "main" java.lang.NumberFormatException: For input string: "null" 
     at java.lang.NumberFormatException.forInputString(Unknown Source) 
     at java.lang.Integer.parseInt(Unknown Source) 
     at java.lang.Integer.parseInt(Unknown Source) 
     at Python_Compiler.main(Python_Compiler.java:66) 

Answer 1

Process p = Runtime.getRuntime().exec("cmd /C python result", null, new java.io.File(myDirectory));
应该是：
Process p = Runtime.getRuntime().exec("cmd /C python " + result + ".py", null, new java.io.File(myDirectory));

你想传入字符串的值result不是文字'结果'。

此外，您的myDirectory变量必须包含一个有效的目录，如“C：\”而不仅仅是“C：”。因此，您可能需要修改该变量，如下所示： myDirectory = myDirectory + "\\";