不管什么技术,不管什么问题,只要努力就能解决。
最近在做项目的时候,需要java 调用 python 接口,在网上找了一些方法,但是总碰到一些问题,索性将网上的方法和自己的理解总结一下,希望对各位博友有所帮助,也请各位大神不吝赐教。
一:创建环境 Python 环境
import org.python.util.PythonInterpreter; import java.util.Properties; /** * Jython环境,获取Python的实例 * @author webim * */ public class JythonEnvironment { //定义一个静态变量 private static JythonEnvironment INSTANCE = new JythonEnvironment(); /** * 私有构造方法 */ private JythonEnvironment() { } /** * 获取单例 * @return JythonEnvironment */ public static JythonEnvironment getInstance() { return INSTANCE; } /** * 获取python解释器 * @return PythonInterpreter */ public PythonInterpreter getPythonInterpreter() { Properties props = new Properties(); props.put("python.home","path to the Lib folder"); props.put("python.console.encoding", "UTF-8"); // Used to prevent: console: Failed to install '': java.nio.charset.UnsupportedCharsetException: cp0. props.put("python.security.respectJavaAccessibility", "false"); //don't respect java accessibility, so that we can access protected members on subclasses props.put("python.import.site","false"); Properties preprops = System.getProperties(); //对 python 进行初始化 PythonInterpreter.initialize(preprops, props, new String[0]); PythonInterpreter inter = new PythonInterpreter(); return inter; } }
在创建 python 解释器之前,需要初始化 python 环境,参考过一些例子,是没有进行初始化,会进行报下列错误。
org.python.core.PyException: null
at org.python.core.Py.ImportError(Py.java:330) ~[jython-2.7.1b3.jar:na]
at org.python.core.Py.importSiteIfSelected(Py.java:1577) ~[jython-2.7.1b3.jar:na]
at org.python.util.PythonInterpreter.<init>(PythonInterpreter.java:116) ~[jython-2.7.1b3.jar:na]
at org.python.util.PythonInterpreter.<init>(PythonInterpreter.java:94) ~[jython-2.7.1b3.jar:na]
at org.python.util.PythonInterpreter.<init>(PythonInterpreter.java:71) ~[jython-2.7.1b3.jar:na]
at com.sihuatech.puzzlevideo.manage.controller.AAlarmController.getAllAlarmInfo(AAlarmController.java:85) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_152]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_152]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_152]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_152]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133) ~[spring-web-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) [spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872) [spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) [spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) [tomcat-embed-core-8.5.27.jar:8.5.27]
二:调用 python 的接口
因为 python 和 java是两种不同的语言,因此在项目的 controller 、service 和 mapper 中直接出现 Python 的接口,因此自己封装 ExecPython 类,
封装python的接口,目的让 python 接口和java程序分隔开。
import org.python.core.PyFunction; import org.python.core.PyObject; import org.python.util.PythonInterpreter; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Component; import org.springframework.stereotype.Service; import java.util.Map; /*enum的这个用法,可以作为变种的安全单例,值得借鉴哦 ^_^ */ @Service @Component public class ExecPython { public static final Logger logger = LoggerFactory.getLogger(Exception.class); //定义 python 解释器 private static PythonInterpreter inter; public ExecPython() { this.inter = JythonEnvironment.getInstance().getPythonInterpreter(); this.inter.execfile("C:\\test.py"); } //设置 python 脚本的路径 public void setPythonPath (String pythonPath){ this.inter.execfile(pythonPath); } public void execute(String scriptFile, Map<String,String> properties) { logger.info("获取解释器"); try { PyFunction getNetInfo = (PyFunction) inter.get("getNetInfo", PyFunction.class); PyObject netInfo = getNetInfo.__call__(); System.out.println("anwser = " + netInfo.toString()); } catch (Exception e) { e.printStackTrace(); logger.info("Python 脚本文件执行失败"); } } //获取 Python 字符串 public String getString(){
//获取到python 脚本中的接口 PyFunction func = (PyFunction) inter.get("adder", PyFunction.class); PyObject pyobj = func.__call__(); System.out.println("anwser = " + pyobj.toString()); return pyobj.toString(); } // 获取当前数组 public String getArr() { PyFunction getArr = (PyFunction) inter.get("getArr", PyFunction.class); PyObject pyobjTwo = getArr.__call__(); pyobjTwo.__len__(); System.out.println("anwser = " + pyobjTwo.toString()+" len:"+pyobjTwo.__len__()); //将 PyObject 对象转换成 java 对象 //Object object = pyobjTwo.__tojava__(List.class); //List<String> list = (List<String>) object; //将查询到数据转换成一个 JSON 字符串 String result = pyobjTwo.toString(); String JsonStr = "{" + result + "}"; logger.info(JsonStr); logger.info("将查询的结果转换成 JSON 字符串:",JsonStr); return pyobjTwo.toString(); } }
三: python 脚本
def adder():return "{'name':'leilei','age':'18'}"
def getArr():
return ['aaa','bbb']
def getNetInfo():
return [{'DNS':'192.168.12.3','ip':'45.23.16.0'},{'DNS2':'192.168.12.2','ip2':'45.23.16.2'}]