在Windows Server 2016上,我们试图通过JDBC与Jython脚本进行连接,但是它给出以下错误:
java.lang.ClassNotFoundException:java.lang.ClassNotFoundException:com.microsoft.sqlserver.jdbc.SQLServerDriver
RazorSQL,在同一台计算机上,使用以下设置正确连接:
Driver Class: com.microsoft.sqlserver.jdbc.SQLServerDriver
Driver Location: \Program Files (x86)\RazorSQL\drivers\sqlserver\sqljdbc.jar
因此,我们使用此命令将CLASSPATH设置在相同的位置:
set CLASSPATH=C:\Program Files (x86)\RazorSQL\drivers\sqlserver\sqljdbc.jar
...但是运行下面的代码时-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)
这是我们运行Python脚本的方式:
C:\jython2.7.0\bin\jython.exe C:\path_to_our_script.py
RazorSQL的连接状况如何-但是Python无法做到?我们如何清除此CLASSPATH错误?
您必须在运行时使用系统Classloader加载JAR。
请参阅this答案。
以下代码段摘自this要点。
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: [email protected] 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()
也请看-https://wiki.python.org/jython/JythonMonthly/Articles/January2007/3