无法从Jython模块导入Java类

注意：我找到了解决方案并自己回答。不过，我不知道为什么设置是错误的，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感兴趣；如果有人想得到赏金，请回答这个问题

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我正在从事一个现有的JavaEE项目，我需要用Python进行计算。我正处于集成测试的第一阶段，但我已经面临一个问题。我读了，但还是找不到解决办法。我也读过（代码重用的模块和包），但对我来说还不清楚

如果您能解释一下Jython导入系统的工作原理以及如何配置它，我们将不胜感激

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

$ 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

$ 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

导入路径定义为：

$ 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

$ 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

$ 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

我确信Jython会选择路径，因为我在Jython提示符下用

sys.path

检查了它

BuildingType.java

package pendulum.generator;

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

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您需要设置CLASSPATH以及python.path

对于相同的目录布局，这对我很有用：

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

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参考资料：（Jython书）。

在尝试/抓住方法中浪费了很多时间后，我自己找到了答案

.jython必须看起来像这样：

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

---

特别是，将

/path/to/project/build/classes

添加到导入路径是错误的（即使它反映了文件系统的层次结构），而

/path/to/project/build

是正确的，解决了问题。

尝试“from be摆.generator import BuildingType”ImportError:无法在jre/lib/ext中导入name BuildingTypeIs jython.jar？不，它位于./.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Myproject/WEB-INF/lib/jython.jar中。我将在jre/lib/ext中复制它并进行测试。[1]可能它需要位于Java类路径以及Python sys.path（？）[2]尝试使用“-v”选项运行jython来调试导入。非常感谢。没有设置classpath，我无法从命令行（

java.lang.ClassNotFoundException

）使用我的类。不过，从Eclipse内部来看，一切都很好。