無法從Jython模塊導入Java類

Question

注：我找到了解決方案並自己回答。雖然，我不知道爲什麼這種設置是錯誤的並導致了問題。我仍然對Jython導入系統的工作原理有很好的解釋。如果有人關心獲得賞金，請回答。

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我正在研究現有的Java EE項目，我需要在Python中進行計算。我處於集成測試的第一階段，但我已經面臨一個問題。我讀Chapter 10 of Jython book但仍然找不到解決方案。我也讀Chapter 8（代碼重用的模塊和包），但對我來說目前還不清楚。

Jython導入系統如何工作以及如何配置它的說明將非常感謝。

問題：

$ 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 

我的問題是：什麼我做錯了，我怎麼解決的事情，成功導入BuildingType接口？也許問題在於CLASSPATH，但我不知道哪個值可能適合。

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代碼組織：由private Jython registry file定義

$ 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 

導入路徑：

$ 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拿起路徑，因爲我檢查與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方法浪費了很多時間之後，我能夠自己找到答案。

.jython 有看起來像這樣：

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 

不是這個：

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的導入路徑是錯誤（即使它反映了文件系統層次結構），而/path/to/project/build是正確的，並解決了這個問題。

Answer 2

您需要設置CLASSPATH以及python.path。

在相同的目錄佈局，這個工作對我來說：

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 

參考：Working with CLASSPATH（Jython的書）。