[Python知识库]Java调用Python的方法

1.首先引入Maven依赖
可以登陆Maven网站，查找jython-standalone的依赖，选中使用较多使用的版本即可，此处以2.7.0为例：

<dependency>
	<groupId>org.python</groupId>
	<artifactId>jython-standalone</artifactId>
	<version>2.7.0</version>
</dependency>

2.编写python函数，此处以pycharm为例，写一个快排，并经过测试争取无误后即可使用

def partition(arr, low, high):
    i = (low-1)
    pivot = arr[high]
    for j in range(low, high):
        if arr[j] <= pivot:
            i = i + 1
            arr[i], arr[j] = arr[j], arr[i]
    arr[i+1], arr[high] = arr[high], arr[i+1]
    return i + 1

def quick_sort(arr, low, high):
    if low < high:
        pi = partition(arr, low, high)
        quick_sort(arr, low, pi-1)
        quick_sort(arr, pi + 1, high)
#调用快排
def do_sort(nums):
    arr = nums
    n = len(arr)
    quick_sort(arr, 0, n-1)
    return arr

# if __name__ == '__main__':
#     nums = [56, 8, 4, 23, 5, 19]
#     res = do_sort(nums)
#     print(res)

3.编写Java代码对上述快排进行调用

package com.example.graduation.controller;

import com.example.graduation.bean.data;
import com.example.graduation.service.DataService;
import org.python.core.PyFunction;
import org.python.core.PyList;
import org.python.core.PyObject;
import org.python.util.PythonInterpreter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

@Controller
public class DataController {

	//重点是此函数
    @RequestMapping("/test")
    @ResponseBody
    public String test(){
        //生成可以调用python的对象
        PythonInterpreter interpreter = new PythonInterpreter();
        //生成100以内的随机数
        Random random = new Random();
        List<Integer> list = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            list.add(random.nextInt(100));
        }
        //调用python文件
        interpreter.execfile("F:\\WK\\Python\\experiment\\graduation\\test.py");
        PyFunction function = interpreter.get("do_sort", PyFunction.class);
        PyObject obj = function.__call__(new PyList(list));
        return obj.toString();
    }
}

4.启动springboot项目

5.浏览器访问http://localhost:8080/test