无法从Jython模块导入Java类

Question

注：我找到了解决方案并自己回答。虽然，我不知道为什么这种设置是错误的并导致了问题。我仍然对Jython导入系统的工作原理有很好的解释。如果有人关心获得赏金，请回答。

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我正在研究现有的Java EE项目，我需要在Python中进行计算。我处于集成测试的第一阶段，但我已经面临一个问题。我读Chapter 10 of Jython book但仍然找不到解决方案。我也读Chapter 8（代码重用的模块和包），但对我来说目前还不清楚。

Jython导入系统如何工作以及如何配置它的说明将非常感谢。

问题：

$ jython -v 
import: 'exceptions' as org.python.core.exceptions in builtin modules 
Jython 2.5.3 (2.5:c56500f08d34+, Aug 13 2012, 14:54:35) 
[Java HotSpot(TM) Server VM (Oracle Corporation)] on java1.7.0_10 
import: import site # precompiled from /home/me/jython/2.5.3/Lib/site$py.class 
import: 'sys' as sys in builtin modules 
import: import os # precompiled from /home/me/jython/2.5.3/Lib/os$py.class 
import: 'errno' as org.python.modules.errno in builtin modules 
import: 'posix' as org.python.modules.posix.PosixModule in builtin modules 
import: import posixpath # precompiled from /home/me/jython/2.5.3/Lib/posixpath$py.class 
import: import stat # precompiled from /home/me/jython/2.5.3/Lib/stat$py.class 
import: 'java' as java package 
import: 'File' as java class 
import: 'IOException' as java class 
import: 'org' as java package 
import: 'Py' as java class 
Type "help", "copyright", "credits" or "license" for more information. 

>>> import pendulum.generator.BuildingType 
import: import pendulum # precompiled from /path/to/project/build/classes/pendulum/__init__$py.class 
import: import pendulum.generator # precompiled from /path/to/project/build/classes/pendulum/generator/__init__$py.class 
Traceback (most recent call last): 
    File "<stdin>", line 1, in <module> 
ImportError: No module named BuildingType 

我的问题是：什么我做错了，我怎么解决的事情，成功导入BuildingType接口？也许问题在于CLASSPATH，但我不知道哪个值可能适合。

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代码组织：由private Jython registry file定义

$ tree build/classes/pendulum/generator/ src/pendulum/generator/ 
build/classes/pendulum/generator/ 
├── BuildingType.class 
├── __init__.py 
└── __init__$py.class 

src/pendulum/generator/ 
├── BuildingType.java 
└── __init__.py 

导入路径：

$ cat ~/.jython 
python.path=\ 
/path/to/project/build/classes:\ 
/path/to/project/src:\ 
/home/me/jdevel/extras/2.5.3/Lib:\ 
/home/me/jdevel/extras/2.5.3/Lib/site-packages 

我敢肯定的Jython拿起路径，因为我检查与sys.path在Jython提示符下。

BuildingType.java

package pendulum.generator; 

public interface BuildingType { 
    public String getBuildingName(); 
    public String getBuildingAddress(); 
    public String getBuildingId(); 
} 

Answer 1

在try/catch方法浪费了很多时间之后，我能够自己找到答案。

.jython 有看起来像这样：

python.path=\ 
/path/to/project/build:\ 
/path/to/project/src:\ 
/home/me/jdevel/extras/2.5.3/Lib:\ 
/home/me/jdevel/extras/2.5.3/Lib/site-packages 

不是这个：

python.path=\ 
/path/to/project/build/classes:\ 
/path/to/project/src:\ 
/home/me/jdevel/extras/2.5.3/Lib:\ 
/home/me/jdevel/extras/2.5.3/Lib/site-packages 

尤其加入/path/to/project/build/classes的导入路径是错误（即使它反映了文件系统层次结构），而/path/to/project/build是正确的，并解决了这个问题。

Answer 2

您需要设置CLASSPATH以及python.path。

在相同的目录布局，这个工作对我来说：

jython10$ CLASSPATH=build/classes/ jython -v Building.py 
import: 'exceptions' as org.python.core.exceptions in builtin modules 
import: import site # precompiled from /usr/local/Java/jython2.5.3/Lib/site$py.class 
import: 'sys' as sys in builtin modules 
import: import os # precompiled from /usr/local/Java/jython2.5.3/Lib/os$py.class 
import: 'errno' as org.python.modules.errno in builtin modules 
import: 'posix' as org.python.modules.posix.PosixModule in builtin modules 
import: import posixpath # precompiled from /usr/local/Java/jython2.5.3/Lib/posixpath$py.class 
import: import stat # precompiled from /usr/local/Java/jython2.5.3/Lib/stat$py.class 
import: java package as '/Users/sdm7g/jaxp/jython10/build/classes/pendulum' 
import: 'pendulum' as java package 
import: 'pendulum' as java package 
import: java package as '/Users/sdm7g/jaxp/jython10/build/classes/pendulum/generator' 
import: 'pendulum.generator' as java package 
import: 'BuildingType' as java class 

参考：Working with CLASSPATH（Jython的书）。