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很多朋友都想知道java怎么調python？下面就一起來了解一下吧~
java調python主要有兩種方法：1.使用Runtime.getRuntime()執行腳本文件；2. 將python腳本寫成進程為java提供服務，下面是具體的方法介紹：
第一種：使用Runtime.getRuntime()執行腳本文件
先建立python腳本文件 demo.py
import?numpy?as?np a?=?np.arange(12).reshape(3,4)print(a)
java調用python程序并輸出該結果
import?java.io.BufferedReader;import?java.io.IOException;import?java.io.InputStreamReader;public?class?Demo?{
????public?static?void?main(String[]?args)?{
????????//?TODO?Auto-generated?method?stub
????????Process?proc;
????????try?{
????????????proc?=?Runtime.getRuntime().exec("python?D:\\demo.py");//?執行py文件
????????????//用輸入輸出流來截取結果
????????????BufferedReader?in?=?new?BufferedReader(new?InputStreamReader(proc.getInputStream()));
????????????String?line?=?null;
????????????while?((line?=?in.readLine())?!=?null)?{
????????????????System.out.println(line);
????????????}
????????????in.close();
????????????proc.waitFor();
????????}?catch?(IOException?e)?{
????????????e.printStackTrace();
????????}?catch?(InterruptedException?e)?{
????????????e.printStackTrace();
????????}?
????}}如若向python程序中函數傳遞參數并執行出結果，下面就舉一例來說明一下。同樣建立python腳本文件demo2.py
import?sys def?func(a,b): ????return?(a+b)if?__name__?==?'__main__': ????a?=?[] ????for?i?in?range(1,?len(sys.argv)): ????????a.append((int(sys.argv[i]))) ????print(func(a[0],a[1]))
其中sys.argv用于獲取參數url1，url2等。而sys.argv[0]代表python程序名，所以列表從1開始讀取參數。以上代碼實現一個兩個數做加法的程序，下面看看在java中怎么傳遞函數參數，代碼如下：
int?a?=?18;int?b?=?23;try?{
????String[]?args?=?new?String[]?{?"python",?"D:\\demo2.py",?String.valueOf(a),?String.valueOf(b)?};
????Process?proc?=?Runtime.getRuntime().exec(args);//?執行py文件
????BufferedReader?in?=?new?BufferedReader(new?InputStreamReader(proc.getInputStream()));
????String?line?=?null;
????while?((line?=?in.readLine())?!=?null)?{
????????System.out.println(line);
????}
????in.close();
????proc.waitFor();}?catch?(IOException?e)?{
????e.printStackTrace();}?catch?(InterruptedException?e)?{
????e.printStackTrace();}其中args是String[] { “python”,path,url1,url2 }; ，path是python程序所在的路徑，url1是參數1，url2是參數2，以此類推。
2. 將python腳本寫成進程為java提供服務
python腳本文件如下：
import?socketimport?sysimport?threadingimport?numpy?as?npfrom?PIL?import?Imagedef?main():
????#?創建服務器套接字
????serversocket?=?socket.socket(socket.AF_INET,socket.SOCK_STREAM)
????#?獲取本地主機名稱
????host?=?socket.gethostname()
????#?設置一個端口
????port?=?12345
????#?將套接字與本地主機和端口綁定
????serversocket.bind((host,port))
????#?設置監聽最大連接數
????serversocket.listen(5)
????#?獲取本地服務器的連接信息
????myaddr?=?serversocket.getsockname()
????print("服務器地址:%s"%str(myaddr))
????#?循環等待接受客戶端信息
????while?True:
????????#?獲取一個客戶端連接
????????clientsocket,addr?=?serversocket.accept()
????????print("連接地址:%s"?%?str(addr))
????????try:
????????????t?=?ServerThreading(clientsocket)#為每一個請求開啟一個處理線程
????????????t.start()
????????????pass
????????except?Exception?as?identifier:
????????????print(identifier)
????????????pass
????????pass
????serversocket.close()
????passclass?ServerThreading(threading.Thread):
????#?words?=?text2vec.load_lexicon()
????def?__init__(self,clientsocket,recvsize=1024*1024,encoding="utf-8"):
????????threading.Thread.__init__(self)
????????self._socket?=?clientsocket
????????self._recvsize?=?recvsize
????????self._encoding?=?encoding????????pass
????def?run(self):
????????print("開啟線程.....")
????????try:
????????????#接受數據
????????????msg?=?''
????????????while?True:
????????????????#?讀取recvsize個字節
????????????????rec?=?self._socket.recv(self._recvsize)
????????????????#?解碼
????????????????msg?+=?rec.decode(self._encoding)
????????????????#?文本接受是否完畢，因為python?socket不能自己判斷接收數據是否完畢，
????????????????#?所以需要自定義協議標志數據接受完畢
????????????????if?msg.strip().endswith('over'):
????????????????????msg=msg[:-4]
????????????????????break
???????????
????????????sendmsg?=?Image.open(msg)
????????????#?發送數據
????????????self._socket.send(("%s"%sendmsg).encode(self._encoding))
????????????pass
????????except?Exception?as?identifier:
????????????self._socket.send("500".encode(self._encoding))
????????????print(identifier)
????????????pass
????????finally:
????????????self._socket.close()?
????????print("任務結束.....")
????????
????????pass
????def?__del__(self):
????????passif?__name__?==?"__main__":
????main()在java代碼中訪問python進程的代碼：
package?hello;import?java.lang.System;import?java.io.BufferedReader;import?java.io.IOException;import?java.io.InputStreamReader;import?java.net.InetAddress;import?java.net.Socket;import?java.io.OutputStream;import?java.io.PrintStream;import?java.io.InputStream;public?class?hello?{
????public?static?void?main(String[]?args){
????????//System.out.println("Hello?World!");
????????//?TODO?Auto-generated?method?stub
????????try?{
????????????InetAddress?addr?=?InetAddress.getLocalHost();
????????????String?host=addr.getHostName();
????????????//String?ip=addr.getHostAddress().toString();?//獲取本機ip
????????????//log.info("調用遠程接口:host=>"+ip+",port=>"+12345);
????????????//?初始化套接字，設置訪問服務的主機和進程端口號，HOST是訪問python進程的主機名稱，可以是IP地址或者域名，PORT是python進程綁定的端口號
????????????Socket?socket?=?new?Socket(host,12345);
????????????//?獲取輸出流對象
????????????OutputStream?os?=?socket.getOutputStream();
????????????PrintStream?out?=?new?PrintStream(os);
????????????//?發送內容
????????????out.print(?"F:\\xxx\\0000.jpg");
????????????//?告訴服務進程，內容發送完畢，可以開始處理
????????????out.print("over");
????????????//?獲取服務進程的輸入流
????????????InputStream?is?=?socket.getInputStream();
????????????BufferedReader?br?=?new?BufferedReader(new?InputStreamReader(is,"utf-8"));
????????????String?tmp?=?null;
????????????StringBuilder?sb?=?new?StringBuilder();
????????????//?讀取內容
????????????while((tmp=br.readLine())!=null)
????????????????sb.append(tmp).append('\n');
????????????System.out.print(sb);
????????????//?解析結果
????????????//JSONArray?res?=?JSON.parseArray(sb.toString());
????????}?catch?(IOException?e)?{
????????????e.printStackTrace();
????????}finally?{
????????????try?{if(socket!=null)?socket.close();}?catch?(IOException?e)?{}
????????????System.out.print("遠程接口調用結束.");
????????}
??????}}以上就是小編今天的分享，希望可以幫到大家。
