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很多朋友都想知道java怎麼調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()執行腳本檔案;2. 將python腳本寫成進程爲java提供服務,下面是具體的方法介紹:
第一種:使用Runtime.getRuntime()執行腳本檔案
先建立python腳本檔案 demo.py
import numpy as npa = np.arange(12).reshape(3,4)print(a)
java調用python程序並輸出該結果
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檔案 //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並執行出結果,下面就舉一例來說明一下。
同樣建立python腳本檔案demo2.py
import sysdef 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用於獲取參數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中怎麼傳遞函數參數,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檔案 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腳本寫成進程爲java提供服務
python腳本檔案如下:
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() # 設定一個端口 port = 12345 # 將套接字與本地主機和端口綁定 serversocket.bind((host,port)) # 設定監聽最大連接數 serversocket.listen(5) # 獲取本地服務器的連接資訊 myaddr = serversocket.getsockname() print("服務器地址:%s"%str(myaddr)) # 循環等待接受客戶端資訊 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)#爲每一個請求開啓一個處理線程 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("開啓線程.....") 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) # 文字接受是否完畢,因爲python socket不能自己判斷接收數據是否完畢, # 所以需要自訂協議標誌數據接受完畢 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,設定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位址或者域名,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