ImportError：无法导入站点模块及其依赖项：没有名为site的模块

Question

我正在尝试在Windows上运行jython servlet。我甚至无法运行最简单的HelloWorld.py。我收到以下500错误：

message Servlet.init() for servlet [PyServlet] threw exception
 ...
description Le serveur a rencontré une erreur interne qui l''a empêché de satisfaire la requête.
exception
javax.servlet.ServletException: Servlet.init() for servlet [PyServlet] threw exception
 ...
cause mère
ImportError: Cannot import site module and its dependencies: No module named site
Determine if the following attributes are correct:
  * sys.path: ['C:\\apache-tomcat-8.5.24\\webapps\\jython\\WEB-INF\\lib\\Lib', '__classpath__', '__pyclasspath__/']
    This attribute might be including the wrong directories, such as from CPython
  * sys.prefix: C:\apache-tomcat-8.5.24\webapps\jython\WEB-INF\lib
    This attribute is set by the system property python.home, although it can
    be often automatically determined by the location of the Jython jar file

You can use the -S option or python.import.site=false to not import the site module

    org.python.core.Py.ImportError(Py.java:328)
    org.python.core.Py.importSiteIfSelected(Py.java:1563)
    org.python.util.PythonInterpreter.<init>(PythonInterpreter.java:116)
 ...

Jython部署在C:\jython2.7.0

下

我的基本网络应用程序位于C:\apache-tomcat-8.5.24\webapps\jython

下

jython.jar（不是独立jar）被复制为C:\apache-tomcat-8.5.24\webapps\jython\WEB-INF\lib\jython.jar

我的web.xml来自http://www.jython.org/javadoc/org/python/util/PyServlet.html：

<!-- C:\apache-tomcat-8.5.24\webapps\jython\WEB-INF\web.xml -->
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" version="3.1">
   <servlet> 
        <servlet-name>PyServlet</servlet-name> 
        <servlet-class>org.python.util.PyServlet</servlet-class> 
         <init-param> 
            <param-name>python.home</param-name> 
            <param-value>C:\\jython2.7.0</param-value> 
        </init-param> 
       <load-on-startup>1</load-on-startup> 
    </servlet> 
    <servlet-mapping> 
        <servlet-name>PyServlet</servlet-name> 
        <url-pattern>*.py</url-pattern> 
    </servlet-mapping> 
 </web-app>

错误消息显示错误的目录包含在sys.path中。 python.home未从我的初始化参数中获取（为什么会这样？），它是从jython.jar的位置猜测出来的。

PyServlet初始化

我查看了PyServlet的{​​{3}}：

@Override
public void init() {
    Properties props = new Properties();
    // Config parameters
    Enumeration<?> e = getInitParameterNames();
    while (e.hasMoreElements()) {
        String name = (String)e.nextElement();
        props.put(name, getInitParameter(name));
    }
     // ...
        init(props, getServletContext());
    }
    reset();
}

/**
 * PyServlet's initialization can be performed as a ServletContextListener or as a regular
 * servlet, and this is the shared init code. If both initializations are used in a single
 * context, the system state initialization code only runs once.
 */
protected static void init(Properties props, ServletContext context) {
    String rootPath = getRootPath(context);
    context.setAttribute(INIT_ATTR, true);
    Properties baseProps = PySystemState.getBaseProperties();
    // Context parameters
    Enumeration<?> e = context.getInitParameterNames();
    while (e.hasMoreElements()) {
        String name = (String)e.nextElement();
        props.put(name, context.getInitParameter(name));
    }
    if (props.getProperty("python.home") == null
            && baseProps.getProperty("python.home") == null) {
        props.put("python.home", rootPath + "WEB-INF" + File.separator + "lib");
    }
    PySystemState.initialize(baseProps, props, new String[0]);
    // ...
    PySystemState.add_classdir(rootPath + "WEB-INF" + File.separator + "classes");
    PySystemState.add_extdir(rootPath + "WEB-INF" + File.separator + "lib", true);
}

我希望将python.home初始化参数添加为属性，并将该属性用于构造sys.path the initialization code！

我错过了什么？

Answer 1

看起来python路径指的是默认位置。所以你有两个选择来解决这个问题。首先是将Jython库复制到＆＃34; C：\ apache-tomcat-8.5.24 \ webapps \ jython \ WEB-INF \ lib \ Lib＆＃34;中。为了复制jython库，你需要将jython独立jar的内容解压缩到这个文件夹中。

另一个选项是将python路径设置为指向解压缩jython独立jar的位置。代码看起来像这样：

 PythonInterpreter interpreter = null;
    try{
            Properties p = new Properties();
            p.setProperty("python.path", "PATH OF JYTHON");
            p.setProperty("python.home", "PATH OF JYTHON");
            p.setProperty("python.prefix", "PATH OF JYTHON");
            PythonInterpreter.initialize(System.getProperties(), p, new String[] {});
        interpreter = new PythonInterpreter();
    }catch(Exception ex){
        log.error("Exception while creating python interpreter: "+ex.toString());
    }

Answer 2

使用jython-standalone.jar对我有用。

在Maven中：https://mvnrepository.com/artifact/org.python/jython-standalone

pom.xml：

<dependency>
    <groupId>org.python</groupId>
    <artifactId>jython-standalone</artifactId>
    <version>2.7.1</version>
</dependency>

Answer 3

我遇到了这个错误，上面的解决方案对我不起作用。 我们需要将jython-standalone.jar添加到python home而不是提取的Lib文件夹。

p.setProperty("python.path", "PATH TO jython-standalone-2.7.0.jar");

或

JAVA_OPTS="$JAVA_OPTS -Dpython.home=/PATH TO /jython-standalone-2.7.0.jar"

希望这对某人有帮助。

Answer 4

正如有人建议的那样。我使用 jython-standalone 并且运行良好。

<dependency>
     <groupId>org.python</groupId>
     <artifactId>jython-standalone</artifactId>
     <version>2.7.2</version>
</dependency>

@Test
public void givenPythonScript_whenPythonProcessInvoked_thenSuccess() throws Exception {
    PythonInterpreter interpreter = new PythonInterpreter();
    interpreter.execfile(".\\src\\test\\resources\\hello.py");
}