项目中有用到Java调用python的需求，经过各种坑之后，根据业务需求，最终实现Java调用Python的各种情况，现在将总结如下，当然调用的也是Jython，具体原因，下面会介绍，先将代码贴出来。 

    这种方法是调用python文件的函数 ，并且需要将函数中的参数由Java数据类型转换为python的数据类型       

                 <dependency>

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

</dependency>

public class JythonExecPyFile {

private static Log logger = LogFactory.getLog(JythonExecPyFile.class);


  public static PythonInterpreter getPythonEnterpreter(String jythonHome,String jythonJsonHome,String pythonRuleDir){


    Properties props = new Properties();
    //props.put("python.home", "path to the Lib folder");
    props.put("python.home", jythonHome);
    props.put("python.console.encoding", "UTF-8");
    props.put("python.security.respectJavaAccessibility", "false");
    props.put("python.import.site", "false");


    Properties preprops = System.getProperties();


    PythonInterpreter.initialize(preprops, props, new String[0]);
    PythonInterpreter pythonInterpreter = new PythonInterpreter();


    PySystemState sys = Py.getSystemState();
    
    sys.path.add(jythonJsonHome);
    sys.path.add(pythonRuleDir);
    //logger.info("jythonHome: " + jythonHome +"    jythonJsonHome: " + jythonJsonHome + "    pythonRuleDir: " + pythonRuleDir);
    return pythonInterpreter;
  }


  public static void addPythonThirdPartLib(String thirdLibPath){
    PySystemState sys = Py.getSystemState();
    sys.path.add(thirdLibPath);
    sys.path.add(SettingConfiguration.getValue("pythonDir"));
  }




  public static void cleanup(PythonInterpreter interpreter){
    if(interpreter != null){
      interpreter.close();
    }
  }
  
  public static void main(String[] args) {


    PythonInterpreter pythonEnterpreter = getPythonEnterpreter(SettingConfiguration.getValue("jPythonHome"),SettingConfiguration.getValue("jythonJsonHome"),SettingConfiguration.getValue("pythonDir"));
    
    System.out.println("-----------------------------调用有参数python方法执行方法-----------------------------");
    String fileNameWithParams = "D:\\Java\\python344\\age.py";
    pythonEnterpreter.execfile(fileNameWithParams);
    PyFunction func = (PyFunction) pythonEnterpreter.get("judge_age",PyFunction.class);
    PyObject pyobj = func.__call__(new PyString("2000-11-11"),new PyInteger(1));
    
    System.out.println("pyObj: " + pyobj);
    
    System.out.println("-----------------------------调用无参数python方法执行方法-----------------------------");
    String fileNameNoParams = "D:\\svnProject\\testConnectDB.py";
    pythonEnterpreter.execfile(fileNameNoParams);
    PyFunction func2 = (PyFunction) pythonEnterpreter.get("say",PyFunction.class);
    PyObject pyobj2 = func2.__call__();
    System.out.println("pyObj: " + pyobj2);
    
    JythonExecPyFile.cleanup(pythonEnterpreter);

  }

而为了更好的封装，将调用python的参数放到list中，而将返回的数据放到dict中，python将dict转换为json串，然后在java接受到返回结果之后，将json串在转换成java的map类型即可。

public class RuleAndModelExecuteFunction {
  private static Log logger = LogFactory.getLog(RuleAndModelExecuteFunction.class);
  /**
   * 规则一 根据文件名、函数名称 参数列表 执行对应的规则或者模型     0 pass       1 reject      2 nodata
   * param ：fileName, functionName,params,params where from the params of python ,And
   * if contact 为null，或者长度为0，或者为空字符串  则 empty_contacts=1  （反欺诈规则结果）anti_fraud_rules_result='reject'
   * else  anti_fraud_rules_result=‘pass'  empty_contacts=0    0 pass 1
   */


  public static String ruleExecuteMethod(String fileName,String functionName,Object... params){
logger.info("ruleExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName);  
    String returnResult = "";
List<Object> paramList = new ArrayList<Object>();
    for(Object obj:params){
      paramList.add(obj);
    }
    String fileNamePath = SettingConfiguration.getValue(fileName);
    Integer defaultResult = 2;
    
    PythonInterpreter pythonInterpreter = null;
    PyObject pyResult  = new PyObject();
    try {
      pythonInterpreter = JythonExecPyFile.getPythonEnterpreter(SettingConfiguration.getValue("jythonHome"),SettingConfiguration.getValue("jythonJsonHome"),SettingConfiguration.getValue("pythonDir"));
      pythonInterpreter.execfile(fileNamePath);
      PyFunction func = (PyFunction) pythonInterpreter.get(functionName,PyFunction.class);
      pyResult = func.__call__(new PyList(paramList));
    }catch (Exception e){
      defaultResult = 4;
      logger.error("ruleExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName + "\n" + e.getStackTrace());
      e.printStackTrace();
      return RiskRuleResultEnum.fromValue(defaultResult).getValue();
    }finally {
      JythonExecPyFile.cleanup(pythonInterpreter);
    }
    //pyResult返回的结果由原来的String类型修改为和模型一样，返回的Map类型
   /* if(pyResult != null){
        String pyResultStr = pyResult.toString();
        defaultResult = Integer.valueOf(pyResultStr);
        logger.info("RuleAndModelExecuteFunction ruleExecuteMethod result: " + pyResult.toString());
      }else {
        logger.info("RuleAndModelExecuteFunction ruleExecuteMethod result: " + pyResult);
      }*/
    if(pyResult != null){
    Map<String,Object> returnMap = JacksonUtil.convertJson2Map(pyResult.toString());
   if(returnMap.get("result") == null){
    returnResult = RiskRuleResultEnum.fromValue(defaultResult).getValue();
       logger.info("ruleExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName + " result为空，设置为默认值: " + defaultResult);
   }else {
    returnResult = RiskRuleResultEnum.fromValue((Integer) returnMap.get("result")).getValue();
    logger.info("ruleExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName + " result: " + defaultResult);
   }
    }else{
    returnResult = RiskRuleResultEnum.fromValue(defaultResult).getValue();
    }
    logger.info("ruleExecuteMethod result: " + returnResult );
    return returnResult;
  }


  public static Map<String,String> ModelExecuteMethod(String fileName,String functionName,Object... params){
logger.info("ModelExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName);  
Map<String,String> resultMap = new HashMap<String,String>();
Integer defaultResult = 2;
Double defaultData = new Double(0.00);
    List<Object> paramList = new ArrayList<Object>();
    for(Object obj:params){
      paramList.add(obj);
    }


    String fileNamePath = SettingConfiguration.getValue(fileName);
    logger.info("fileNamePath:"+fileNamePath);
    PythonInterpreter pythonInterpreter = null;
    PyObject pyResult = null;
    try {
      pythonInterpreter = JythonExecPyFile.getPythonEnterpreter(SettingConfiguration.getValue("jythonHome"),SettingConfiguration.getValue("jythonJsonHome"),SettingConfiguration.getValue("pythonDir"));
      pythonInterpreter.execfile(fileNamePath);
      PyFunction func = (PyFunction) pythonInterpreter.get(functionName,PyFunction.class);
      PyList pyList = new PyList(paramList);
      pyResult = func.__call__(pyList);
    }catch (Exception e){
      defaultResult = 4;
      defaultData = new Double(-1);;
      logger.error("ModelExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName + "\n" + e.getStackTrace());
      resultMap.put("result", RiskRuleResultEnum.fromValue(defaultResult).getValue());
      resultMap.put("data",defaultData.toString());
      e.printStackTrace();
      return resultMap;
    }finally {
      JythonExecPyFile.cleanup(pythonInterpreter);
    }
    logger.info("return result:"+pyResult.toString());
    Map<String,Object> returnMap = JacksonUtil.convertJson2Map(pyResult.toString());
    if(returnMap.get("result") == null){
    resultMap.put("result",RiskRuleResultEnum.fromValue(defaultResult).getValue());
        logger.info("ModelExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName + " result为空，设置为默认值: " + defaultResult);
    }else {
    resultMap.put("result",RiskRuleResultEnum.fromValue((Integer) returnMap.get("result")).getValue());
    }
    if(returnMap.get("data") == null){
      resultMap.put("data",defaultData.toString());
      logger.info("ModelExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName + " data为空，设置为默认值: " + defaultData);
    }else {
    logger.info("ModelExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName + " data为空，设置为默认值: " + returnMap.get("data"));
      resultMap.put("data",returnMap.get("data").toString());
    }
    
    if (returnMap.get("antifraud_model_saved")!=null) {
    resultMap.put("antifraud_model_saved", JsonUtils.toJson(returnMap.get("antifraud_model_saved")));
}
    if (returnMap.get("android_new_saved")!=null) {
        resultMap.put("android_new_saved", JsonUtils.toJson(returnMap.get("android_new_saved")));
}
    if (returnMap.get("profile_model_saved")!=null) {
    resultMap.put("profile_model_saved", JsonUtils.toJson(returnMap.get("profile_model_saved")));
}
   
    logger.info("RuleAndModelExecuteFunction ModelExecuteMethod result: " +pyResult.toString() );
    return resultMap;
  }
  
  public static Map<String,String> collectionExecuteMethod(String fileName,String functionName,Object... params){
logger.info("ModelExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName);  
Map<String,String> resultMap = new HashMap<String,String>();
    
List<Object> paramList = new ArrayList<Object>();
    for(Object obj:params){
      paramList.add(obj);
    }


    String fileNamePath = SettingConfiguration.getValue(fileName);
    logger.info("fileNamePath:"+fileNamePath);
    PythonInterpreter pythonInterpreter = null;
    PyObject pyResult = null;
    try {
      pythonInterpreter = JythonExecPyFile.getPythonEnterpreter(SettingConfiguration.getValue("jythonHome"),SettingConfiguration.getValue("jythonJsonHome"),SettingConfiguration.getValue("pythonDir"));
      pythonInterpreter.execfile(fileNamePath);
      PyFunction func = (PyFunction) pythonInterpreter.get(functionName,PyFunction.class);
      PyList pyList = new PyList(paramList);
      pyResult = func.__call__(pyList);
    }catch (Exception e){
      logger.error("ModelExecuteMethod param------ fileName: " + fileName + "  functionName: " + functionName + "\n" + e.getStackTrace());
      resultMap.put("result", "error");
      resultMap.put("data","-1");
      e.printStackTrace();
      return resultMap;
    }finally {
      JythonExecPyFile.cleanup(pythonInterpreter);
    }
    logger.info("return result:"+pyResult.toString());
    Map<String,Object> returnMap = JacksonUtil.convertJson2Map(pyResult.toString());
   
    resultMap.put("result", returnMap.get("result").toString());
    resultMap.put("data", returnMap.get("data").toString());
    
    logger.info("RuleAndModelExecuteFunction ModelExecuteMethod result: " +returnMap);
    return resultMap;

  }

public static Map<String, Object> convertJson2Map(String json) {
JsonFactory factory = new JsonFactory();
ObjectMapper mapper = new ObjectMapper(factory);
TypeReference<HashMap<String, Object>> typeRef = new TypeReference<HashMap<String, Object>>() {
};
try {
return mapper.readValue(json, typeRef);
} catch (JsonParseException e) {
e.printStackTrace();
} catch (JsonMappingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;

}

通过这种封装之后，完成了最终的封装，并作为工具类进行调用。

Java调用python由三种方式，分别如下：

第一种方式：

public class HelloPython {public static void main(String[] args) {PythonInterpreter interpreter = new PythonInterpreter();interpreter.exec("print('hello')");}
}

什么是 PythonInterpreter 呢？它的中文意思即“ Python 解释器”。我们知道 Python 程序都是通过解释器执行的，上面的代码就是在 JVM 中创建一个“ Python 解释器”对象，模拟 Python 解释器的行为，通过 exec(" Python 语句") 直接在 JVM 中执行 Python 代码，代码的输出结果为：hello，需要提醒各位的是，该程序运行速度相较正常的 Java or Python 程序都要慢那么一点。

第二种方式：在项目中实际用到，执行的是python文件中的函数，见上面

第三种方式：通过解释器直接执行python文件

第四种方式：该方式是否可以调用python的第三方模块，没有运行，用需求的朋友可以执行一个程序就可以验证

由于 Jython 运行过慢并且不支持第三方的 Python 模块，通过 Java 代码执行一段终端命令来调用 Python 脚本，根据具体问题决定如何交互可能才是实际中真正会用到的方式（详见下面的举例代码）。

举例代码：下面是一个可以识别很粗的手写数字写的一个小程序，界面上引用了 core java 上的一段代码：

运行流程：Java Swing 界面接收用户输入 --> Java 将用户输入写到本地文件中 --> Java 调用本地 Python 脚本 --> Python 从本地文件拿到用户输入 --> Python 处理用户输入得到最终结果 --> Python 把最终结果写到本地文件 --> Java 对 Python 脚本的调用结束 --> Java 从本地文件中取出最终结果 --> Java 把最终结果返回给用户

完整代码链接：http://pan.baidu.com/s/1sl4l68H