Question

我有一个Java程序，读取一个文件（其中包含来自本地语言的字符），然后填充一个字符串。直接运行程序时，效果很好。

但是当从Python调用同一程序时，则无法填充字符串。

        public static void main(String[] args) {
        File inputFile = new File("input.txt");
        BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(inputFile),"UTF-8"));
      string output = "";
        while ((line = br.readLine()) != null) {
           // This block never hits when invoked by python. It works fine when java program runs directly.
           output +=line+" ";
         }
         ...
         }

我从Python调用它的方式如下

cmd = ['java', java_class]
subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE)

有输入吗？顺便说一句，我正在使用Atom IDE，不确定是否有什么区别。

Answer 1

我尝试了您的示例，并且对我有用。让我们看看它是否对您有用。然后，我会回复您对这个问题的看法。

import java.io.*;


public class Python2JavaMessaging {
        public static void main(String[] args) {
                try {
                        BufferedReader bufferRead = new BufferedReader(new InputStreamReader(System.in));
                        PrintWriter writer = new PrintWriter("result.txt", "UTF-8");
                        String s = bufferRead.readLine();
                        while(s.equals("x")==false) {
                                writer.println(s);
                                s = bufferRead.readLine();
                        }
                        writer.close();
                } catch(IOException e) {
                        e.printStackTrace();
                }
        }
}

Python脚本如下：

#!/usr/bin/python

import subprocess

cmd = ['java', '-classpath', '.' , 'Python2JavaMessaging']
p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, encoding='utf8')

p.stdin.write("First line\r\n")
p.stdin.write("Second line\r\n")
p.stdin.write("x\r\n") # this line will not be printed into the file

从python调用Java应用程序时无法读取文件

1 个答案: