将java对象传递给python

Question

我正在为我们的应用程序创建一个接口原型,以允许其他人使用python,我们的应用程序是用java编写的.我想将我们的一些数据从Java应用程序传递给python代码,但我不确定如何将对象传递给python.我使用简单的参数使用Jython做了一个简单的java-> python函数调用,发现它对我想要做的事情非常有用.鉴于下面的类,我如何在Python/Jython中将它用作函数/类的输入:

public class TestObject 
{
   private double[] values;
   private int length;
   private int anotherVariable;

   //getters, setters
 }

Answer 1

一个解决方案 您可以使用某种类型的消息系统,队列或某种代理来序列化/反序列化,或者在python和java之间传递消息.然后创建一些排序工作者/生产者/消费者,将工作放在要在python或java中处理的队列上.

还可以考虑寻找灵感:https://www.py4j.org/

py4j被/用于pyspark和hadoop类型的东西.

更快地回答你的问题.

使用json-simple的示例:

import org.apache.commons.io.FileUtils;
import org.json.simple.JSONObject;
 //import org.json.simple.JSONObject;


public class TestObject 
{
   private double[] values;
   private int length;
   private int anotherVariable;
   private boolean someBool;
   private String someString;

   //getters, setters

   public String toJSON() {
       JSONObject obj=new JSONObject();
       obj.put("values",new Double(this.values));
       obj.put("length",new Integer(this.length));
       obj.put("bool_val",new Boolean(this.SomeBool));
       obj.put("string_key",this.someString);
       StringWriter out = new StringWriter();
       obj.writeJSONString(out);
       return out.toString();
   }

   public void writeObject(){
          Writer writer = new BufferedWriter(
                              new OutputStreamWriter(
                                  new FileOutputStream("anObject.json"), "utf-8")
                              )
                           )

          writer.write(this.toJSON());
   }

   public static void setObject(){
       values = 100.134;
       length = 12;
       anotherVariable = 15;
       someString = "spam";
   }
 }

在python中:

class DoStuffWithObject(object):
    def __init__(self,obj):
        self.obj = obj
        self.changeObj()
        self.writeObj()

    def changeObj(self):
        self.obj['values'] = 100.134;
        self.obj['length'] = 12;
        self.obj['anotherVariable'] = 15;
        self.obj['someString'] = "spam";

    def writeObj(self):
        ''' write back to file '''
        with open('anObject.json', 'w') as f:
            json.dump(self.obj, f)

    def someOtherMethod(self, s):
       ''' do something else '''
       print('hello {}'.format(s))

import json
with open('anObject.json','r') as f:
    obj = json.loads(f.read())
# print out obj['values'] obj['someBool'] ...
for key in obj:
    print(key, obj[key])

aThing = DoStuffWithObject(obj)
aThing.someOtherMethod('there')

然后在java中读回对象.存在实现此想法的解决方案(JSON-RPC,XML-RPC和变体).您可能还想考虑使用类似(http://docs.mongodb.org/ecosystem/drivers/java/)这样的好处,即mongo做json的好处.

看到:

• https://spring.io/guides/gs/messaging-reactor/
• http://spring.io/guides/gs/messaging-rabbitmq/
• http://spring.io/guides/gs/scheduling-tasks/
• 芹菜喜欢Java项目
• Jedis
• 的RabbitMQ
• ZeroMQ

更全面的队列列表:

• http://queues.io/

参考资源:

• http://www.oracle.com/technetwork/articles/java/json-1973242.html
• 如何创建文件并用Java写入？
• https://code.google.com/p/json-simple/wiki/EncodingExamples