我在使用Jython和SQLite jar文件时遇到了一些问题。由于某种原因，我的应用程序无法加载 Sqlite JDBC 类并抛出java.lang.ClassNotFoundException: java.lang.ClassNotFoundException: org.sqlite.JDBC错误。
我从 http://code.google.com/p/sqlitebot/downloads/detail?name=sqlitejdbc-v056.jar 下载了jdbc jar文件。
我的项目结构
/我的项目
/myproject/Lib/sqlitejdbc.jar
/myproject/jython.jar （单机版）
/myproject/application.py
我正在使用的命令：
$ java -jar jython.jar -Dpython.path=Lib/sqlitejdbc.jar Application.py
我为 sys.path 属性获得的输出
['/Users/[User]/[ProjectLocation]/[ProjectName]', '/Users/[User]/[ProjectLocation]/[ProjectName]/Lib/sqlitejdbc.jar', '/Users/[User]/[ProjectLocation]/[ProjectName]/Lib', '/Users/[User]/[ProjectLocation]/[ProjectName]/jython.jar/Lib', '__classpath__', '__pyclasspath__/']
Application.py 来源：
################################################################################
#
# sqlite_using_jdbc - An example of using straight JDBC mechanisms to
# interact with a SQLite database.
# Creates a 'planet' table in a SQLite database
# named 'solarsys.db', populates it with some data and
# then executes a query to retrieve data from that table.
#
# Works with Jython 2.5, must have the zentus sqlitejdbc.jar in your
# CLASSPATH at execution time.
# Known to work with sqlitejdbc-v056.jar
#
################################################################################
import sys
print sys.path
# sys.exit(0)
from java.lang import Class
from java.sql import DriverManager, SQLException
################################################################################
DATABASE = "solarsys.db"
JDBC_URL = "jdbc:sqlite:%s" % DATABASE
JDBC_DRIVER = "org.sqlite.JDBC"
TABLE_NAME = "planet"
TABLE_DROPPER = "drop table if exists %s;" % TABLE_NAME
TABLE_CREATOR = "create table %s (name, size, solar_distance);" % TABLE_NAME
RECORD_INSERTER = "insert into %s values (?, ?, ?);" % TABLE_NAME
PLANET_QUERY = """
select name, size, solar_distance
from %s
order by size, solar_distance desc
""" % TABLE_NAME
PLANET_DATA = [('mercury' , 'small' , 57), # distance in million kilometers
('venus' , 'small' , 107),
('earth' , 'small' , 150),
('mars' , 'small' , 229),
('jupiter' , 'large' , 777),
('saturn' , 'large' , 888),
('uranus' , 'medium', 2871),
('neptune' , 'medium', 4496),
('pluto' , 'tiny' , 5869),
]
################################################################################
def main():
dbConn = getConnection(JDBC_URL, JDBC_DRIVER)
stmt = dbConn.createStatement()
try:
stmt.executeUpdate(TABLE_DROPPER)
stmt.executeUpdate(TABLE_CREATOR)
except SQLException, msg:
print msg
sys.exit(1)
if populateTable(dbConn, PLANET_DATA):
resultSet = stmt.executeQuery(PLANET_QUERY)
while resultSet.next():
name = resultSet.getString("name")
size = resultSet.getString("size")
dist = resultSet.getInt ("solar_distance")
print "%-16.16s %-8.8s %4d" % (name, size, dist)
stmt.close()
dbConn.close()
sys.exit(0)
################################################################################
def getConnection(jdbc_url, driverName):
"""
Given the name of a JDBC driver class and the url to be used
to connect to a database, attempt to obtain a connection to
the database.
"""
try:
Class.forName(driverName).newInstance()
except Exception, msg:
print msg
sys.exit(-1)
try:
dbConn = DriverManager.getConnection(jdbc_url)
except SQLException, msg:
print msg
sys.exit(-1)
return dbConn
################################################################################
def populateTable(dbConn, feedstock):
"""
Given an open connection to a SQLite database and a list of tuples
with the data to be inserted, insert the data into the target table.
"""
try:
preppedStmt = dbConn.prepareStatement(RECORD_INSERTER)
for name, size, distance in feedstock:
preppedStmt.setString(1, name)
preppedStmt.setString(2, size)
preppedStmt.setInt (3, distance)
preppedStmt.addBatch()
dbConn.setAutoCommit(False)
preppedStmt.executeBatch()
dbConn.setAutoCommit(True)
except SQLException, msg:
print msg
return False
return True
################################################################################
################################################################################
if __name__ == '__main__':
main()
sqlitejdbc.jar中的类也需要在java类路径上可用，这在使用独立的jython时实际上很棘手.jar通过java -jar。 从 Java 文档...
-.jar
使用此选项时，JAR 文件是所有用户类的源，其他用户类路径设置将被忽略。
因此，使用 -jar 时无法向类路径添加任何内容。 但是，请参阅此答案以获取解决方案 - 基本上将jython.jar也添加到类路径中（使用-cp或CLASSPATH）并直接运行org.python.util.jython类。