为什么 CLASSPATH 对 Python 失败但对 RazorSQL 有效?
Why is the CLASSPATH failing for Python but working for RazorSQL?
在 Windows Server 2016 上,我们正在尝试使用 Jython 脚本通过 JDBC 进行连接,但出现以下错误:
java.lang.ClassNotFoundException: java.lang.ClassNotFoundException:
com.microsoft.sqlserver.jdbc.SQLServerDriver
RazorSQL,在同一台机器上,使用这些设置连接没有错误:
Driver Class: com.microsoft.sqlserver.jdbc.SQLServerDriver
Driver Location: \Program Files (x86)\RazorSQL\drivers\sqlserver\sqljdbc.jar
因此,我们使用以下命令将 CLASSPATH 设置到相同的位置:
set CLASSPATH=C:\Program Files (x86)\RazorSQL\drivers\sqlserver\sqljdbc.jar
...但是当 运行 下面的代码时 - 我们仍然会遇到相同的 ClassNotFound 错误。
这是我们的 Python 代码:
jclassname = "com.microsoft.sqlserver.jdbc.SQLServerDriver"
database = "our_database_name"
db_elem = ";databaseName={}".format(database) if database else ""
host = "###.##.###.###" # ip address
port = "1433"
user = "user_name"
password = "password"
url = (
jdbc:sqlserver://{host}:{port}{db_elem}"
";user={user};password={password}".format(
host=host, port=port, db_elem=db_elem,
er=user, password=password)
)
print url
driver_args = [url]
jars = None
libs = None
db = jaydebeapi.connect(jclassname, driver_args, jars=jars,
libs=libs)
这就是我们 运行 我们的 Python 脚本:
C:\jython2.7.0\bin\jython.exe C:\path_to_our_script.py
RazorSQL 如何连接正常 - 但不知何故 Python 不能?我们如何消除这个 CLASSPATH 错误?
您必须在运行时使用系统类加载器加载 JAR。
请参考this回答
以下代码片段摘自 this Gist。
def loadJar(jarFile):
'''load a jar at runtime using the system Classloader (needed for JDBC)
adapted from http://forum.java.sun.com/thread.jspa?threadID=300557
Author: Steve (SG) Langer Jan 2007 translated the above Java to Jython
Reference: https://wiki.python.org/jython/JythonMonthly/Articles/January2007/3
Author: seansummers@gmail.com simplified and updated for jython-2.5.3b3+
>>> loadJar('jtds-1.3.1.jar')
>>> from java import lang, sql
>>> lang.Class.forName('net.sourceforge.jtds.jdbc.Driver')
<type 'net.sourceforge.jtds.jdbc.Driver'>
>>> sql.DriverManager.getDriver('jdbc:jtds://server')
jTDS 1.3.1
'''
from java import io, net, lang
u = io.File(jarFile).toURL() if type(jarFile) <> net.URL else jarFile
m = net.URLClassLoader.getDeclaredMethod('addURL', [net.URL])
m.accessible = 1
m.invoke(lang.ClassLoader.getSystemClassLoader(), [u])
if __name__ == '__main__':
import doctest
doctest.testmod()
也看看- https://wiki.python.org/jython/JythonMonthly/Articles/January2007/3
在 Windows Server 2016 上,我们正在尝试使用 Jython 脚本通过 JDBC 进行连接,但出现以下错误:
java.lang.ClassNotFoundException: java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver
RazorSQL,在同一台机器上,使用这些设置连接没有错误:
Driver Class: com.microsoft.sqlserver.jdbc.SQLServerDriver
Driver Location: \Program Files (x86)\RazorSQL\drivers\sqlserver\sqljdbc.jar
因此,我们使用以下命令将 CLASSPATH 设置到相同的位置:
set CLASSPATH=C:\Program Files (x86)\RazorSQL\drivers\sqlserver\sqljdbc.jar
...但是当 运行 下面的代码时 - 我们仍然会遇到相同的 ClassNotFound 错误。
这是我们的 Python 代码:
jclassname = "com.microsoft.sqlserver.jdbc.SQLServerDriver"
database = "our_database_name"
db_elem = ";databaseName={}".format(database) if database else ""
host = "###.##.###.###" # ip address
port = "1433"
user = "user_name"
password = "password"
url = (
jdbc:sqlserver://{host}:{port}{db_elem}"
";user={user};password={password}".format(
host=host, port=port, db_elem=db_elem,
er=user, password=password)
)
print url
driver_args = [url]
jars = None
libs = None
db = jaydebeapi.connect(jclassname, driver_args, jars=jars,
libs=libs)
这就是我们 运行 我们的 Python 脚本:
C:\jython2.7.0\bin\jython.exe C:\path_to_our_script.py
RazorSQL 如何连接正常 - 但不知何故 Python 不能?我们如何消除这个 CLASSPATH 错误?
您必须在运行时使用系统类加载器加载 JAR。
请参考this回答
以下代码片段摘自 this Gist。
def loadJar(jarFile): '''load a jar at runtime using the system Classloader (needed for JDBC) adapted from http://forum.java.sun.com/thread.jspa?threadID=300557 Author: Steve (SG) Langer Jan 2007 translated the above Java to Jython Reference: https://wiki.python.org/jython/JythonMonthly/Articles/January2007/3 Author: seansummers@gmail.com simplified and updated for jython-2.5.3b3+ >>> loadJar('jtds-1.3.1.jar') >>> from java import lang, sql >>> lang.Class.forName('net.sourceforge.jtds.jdbc.Driver') <type 'net.sourceforge.jtds.jdbc.Driver'> >>> sql.DriverManager.getDriver('jdbc:jtds://server') jTDS 1.3.1 ''' from java import io, net, lang u = io.File(jarFile).toURL() if type(jarFile) <> net.URL else jarFile m = net.URLClassLoader.getDeclaredMethod('addURL', [net.URL]) m.accessible = 1 m.invoke(lang.ClassLoader.getSystemClassLoader(), [u]) if __name__ == '__main__': import doctest doctest.testmod()
也看看- https://wiki.python.org/jython/JythonMonthly/Articles/January2007/3