导入错误:无法导入站点模块及其依赖项:没有名为站点的模块

Question

我正在尝试在Windows上运行jython servlets。我甚至不能运行最简单的 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-8.5.24webappsjythonWEB-INFlib
    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

我最基本的网络应用程序正在C:apache-tomcat-8.5.24webappsjython

jython.jar(不是独立 jar(被复制为C:apache-tomcat-8.5.24webappsjythonWEB-INFlibjython.jar

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

<!-- C:apache-tomcat-8.5.24webappsjythonWEB-INFweb.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>

错误消息说，sys.path中包含错误的目录。 python.home不是从我的初始化参数中获取的(为什么会这样？(，而是从jython.jar的位置猜测的。

PyServlet初始化

我看了一下PyServlet的初始化代码：

@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，并且该属性用于构造 JavaDoc 中所示的sys.path！

我错过了什么？

Answer 1

使用 jython-standalone.jar 对我有用。

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

绒球.xml：

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

Answer 2

看起来 python 路径引用了默认位置。因此，您有两种选择来解决此问题。首先是将 Jython 库复制到 "C：\apache-tomcat-8.5.24\webapps\jython\WEB-INF\lib\Lib" 中。为了复制jython库，您需要将jython独立jar的内容解压缩到此文件夹中。

另一种选择是将 python 路径设置为指向解压缩 jython 独立 jar 的位置。代码如下所示：

 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 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"

希望这对某人有所帮助。

Answer 4

正如有人建议的那样。我使用了jython-独立并且效果很好。

<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");
}