在Java和python之间进行管道传输（两种方式）

Question

我尝试编写一个python脚本，该脚本从Java文件接收数据并将数据发送给它，但是看来该脚本仅接收数据而不发送数据。 这是python代码：

def java_python_comu():
    compile_java = subprocess.Popen(["javac", "MultiThread.java"])
    compile_java.communicate()

    java_io = subprocess.Popen(["java", "MultiThread"], stdout=subprocess.PIPE, stdin=subprocess.PIPE)
    read_java_output = threading.Thread(target=read, args=(java_io,))
    write_java_input = threading.Thread(target=write_func, args=(java_io, ))

    write_java_input.start()
    read_java_output.start()

def write(pipe, text):
    with MUTEX_LOCK:
        pipe.stdin.write(str2bytes(text + "\n"))

def write_func(pipe):
    write(pipe, "_RIGHT_")
    write(pipe, "_LEFT_")
    write(pipe, "_UP_")
    write(pipe, "_DOWN_")
    write(pipe, "_STOP_")
    write(pipe, EXIT_VALUE)

def read(pipe):
    with MUTEX_LOCK:
        line = pipe.stdout.readline()
    line = str(line.decode("utf-8"))
    while not line.count(EXIT_VALUE):
        if not (line == "" or line.count(EXIT_VALUE) or enter(line)):
            print("JAVA: " + line, end="")
        with MUTEX_LOCK:
            line = pipe.stdout.readline()
        line = str(line.decode("utf-8"))
    print("END")

这是Java代码

import java.io.*;
class JavaClass implements Runnable{
    String name;
    Thread t;
    JavaClass (String threadname){
        name = threadname;
        t = new Thread(this, name);
        t.start();
    }

    public void writeToFile(String str){
        File file = new File("1003.txt");
        FileWriter fr = null;
        try {
            fr = new FileWriter(file, true);
            fr.write(str + "\n");
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                fr.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public void read(){
        BufferedReader bufferRead = null;
        String s = "";
        try{
            bufferRead = new BufferedReader(new InputStreamReader(System.in));
        }catch(Exception e){
            writeToFile(e.toString());
        }
        try{
            s = bufferRead.readLine();
        } catch(Exception e) {
            writeToFile(e.toString());
        }
        writeToFile("s: " + s);
        String error1 = "";
        String error2 = "";
        while(s == null || !s.equals("_EXIT_")){
            try{
                if(s != null){
                    if(s.equals("_RIGHT_")){
                        writeToFile("ROBOT: moves backwards");
                    }else if(s.equals("_LEFT_")){
                        writeToFile("ROBOT: moves backwards");
                    }else if(s.equals("_UP_")){
                        writeToFile("ROBOT: moves backwards");
                    }else if(s.equals("_DOWN_")){
                        writeToFile("ROBOT: moves backwards");
                    }
                }
            }catch(Exception e){
                String tmpError = e.toString();
                if(!tmpError.equals(error1)){
                    error1 = tmpError;
                    writeToFile("1" + error1);
                }
            }
            try{
                s = bufferRead.readLine();
            }catch(Exception e){
                String tmpError = e.toString();
                if(!tmpError.equals(error2)){
                    error2 = tmpError;
                    writeToFile("2" + error2);
                }
            }
        }
    }

    public void output(){
        System.out.println("This is the java code");
        System.out.println("Read by the python code");
        System.out.println("And compiled by it");
    }

    public void run() {
        try{
            switch (t.getName()){
                case "input":
                    read();
                    break;
                case "output":
                    output();
                    break;
            }
        }catch (Exception e) {
            System.out.println(name + "Interrupted");
        }
    }
}
public class MultiThread {
    public static void main(String args[]) {
        new JavaClass("input");
        new JavaClass("output");
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            System.out.println("Main thread Interrupted");
        }
        System.out.println("Main thread exiting.");
        System.out.println("__EXIT__");

    }

}

该代码没有给出任何错误，并且每次我检查s时，它都表示它为空。

当我将其分离到不同的文件（一个用于发送信息的脚本和一个用于接收信息的脚本）时，它可以完美地工作。