1.why
python拥有的某些库要比Java强大，也拥有一些比Java更擅长的领域，python可以搭建后端让Java调用接口，但某些时候我们用到的python代码可能并不多也许只有一个算法，此时就需要以下方法了。
2.核心依赖
毫无疑问【自然是python的Java执行器了】
<dependency> <groupId>org.python</groupId> <artifactId>jython-standalone</artifactId> <version>2.7.0</version> </dependency>
3.使用
3.1类型一【直接执行python代码】
public class ExecPythonCode { public static void main(String[] args) { PythonInterpreter interpreter = new PythonInterpreter(); interpreter.exec("a=[5,2,3,9,4,0];"); // 此处python语句是3.x版本的语法 interpreter.exec("print(sorted(a));"); // 此处是python语句是2.x版本的语法 interpreter.exec("print sorted(a);"); interpreter.close(); } }
3.2类型二【执行python文件后获取返回结果】
- 无参数的python文件执行
public class ExecPythonFile { public static void main(String[] args) { try { Process process = Runtime.getRuntime() .exec("python D:\\PythonFile.py"); BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream())); String line = null; while ((line = in.readLine()) != null) { System.out.println(line); } in.close(); process.waitFor(); } catch (IOException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); } } }
- 带参数的python文件执行
public class ExecPythonFileWithArgs { public static void main(String[] args) { int a = 18, b = 19; args = new String[] { "python","D:\\PythonFileWithArgs.py", String.valueOf(a), String.valueOf(b) }; try { Process process = Runtime.getRuntime().exec(args); BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream())); String line = null; while ((line = in.readLine()) != null) { System.out.println(line); } in.close(); process.waitFor(); } catch (IOException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); } } }
- 【Windows环境】使用bat脚本执行python文件【我猜想也是有Linux环境的执行方法的】
public class ExecPythonBat { public static void main(String[] args) { try { Process process = Runtime.getRuntime().exec("cmd /c D:\\RunPythonFile.bat"); BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream())); String line = null; while ((line = in.readLine()) != null) { System.out.println(line); } in.close(); process.waitFor(); } catch (IOException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); } } }
3.3类型三【读取python文件内的函数进行执行】
public class ExecPythonFileCode { public static void main(String[] args) { PythonInterpreter interpreter = new PythonInterpreter(); interpreter.execfile("D:\\PythonFile.py"); PyFunction function = interpreter.get("add", PyFunction.class); int a = 3, b = 12; PyObject pyObject = function.__call__(new PyInteger(a), new PyInteger(b)); System.out.println("The result is : " + pyObject); interpreter.close(); } }
4.python文件和执行脚本
文件一：PythonFile.py
import numpy as np a = np.arange(12).reshape(3,4) print(a) def add(a,b): return a+b;
文件二：PythonFileWithArgs.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]))
文件三：RunPythonFile.bat
@echo off cmd /k python E:\Anaconda3_Python\PythonFile.py
