Jython CLASSPATH，sys.path和JDBC驱动程序 [英] Jython CLASSPATH, sys.path and JDBC drivers

问题描述

如何在运行时将JDBC驱动程序添加到Jython?使用CLASSPATH可以使用，但是即使已很好地导入了类并且可以从Jython解释器提示符处对其进行操作，也不能将sys.path与zxJDBC一起使用.

How can I add JDBC drivers at runtime to Jython? Using CLASSPATH works, but using sys.path doesn't work with zxJDBC even though the class is imported fine and can be manipulated from the Jython interpreter prompt.

为什么这样做:

$ CLASSPATH=/tmp/jtds\-1.2.5.jar ./jython
*sys-package-mgr*: processing new jar, '/private/tmp/jtds-1.2.5.jar'
Jython 2.5.1 (Release_2_5_1:6813, Sep 26 2009, 13:47:54) 
[Java HotSpot(TM) 64-Bit Server VM (Apple Inc.)] on java1.6.0_20
Type "help", "copyright", "credits" or "license" for more information.
>>> from java.lang import Class
>>> Class.forName('net.sourceforge.jtds.jdbc.Driver')
<type 'net.sourceforge.jtds.jdbc.Driver'>

但这不是吗?

$ ./jython

Jython 2.5.1 (Release_2_5_1:6813, Sep 26 2009, 13:47:54) 
[Java HotSpot(TM) 64-Bit Server VM (Apple Inc.)] on java1.6.0_20
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path.extend(['/tmp/jtds-1.2.5.jar'])
>>> from java.lang import Class
>>> Class.forName('net.sourceforge.jtds.jdbc.Driver')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
        at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:169)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)

java.lang.ClassNotFoundException: java.lang.ClassNotFoundException: net.sourceforge.jtds.jdbc.Driver
>>> sys.path
['', '/home/me/pkg/jython2.5.1/Lib/site-packages/distribute-0.6.13-py2.5.egg', '/home/me/pkg/jython2.5.1/Lib', '__classpath__', '__pyclasspath__/', '/home/me/pkg/jython2.5.1/Lib/site-packages', '/home/me/pkg/jython2.5.1/Lib/site-packages/setuptools-0.6c11-py2.5.egg-info', '/tmp/jtds-1.2.5.jar']
>>> import net.sourceforge.jtds.jdbc.Driver as Driver
>>> drv = Driver()
>>> drv
jTDS 1.2.5

它与类加载器有关吗?

Does it have something to do with the classloader?

推荐答案

该解决方案比较棘手，但所有内容均已说明

The solution is tricky, but everything is explained here.

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