Returning zxJDBC Errors in Jython or Sikuli?

Question

I'm having trouble returning zxJDBC errors (in specific, my connection to the MySQL appears to drop due to network issues and this is causing my program to crash/hang), but will be honest that I don't know a great deal returning .jar errors in Jython. Most of my programming experience has been limited to BASH & Perl in the past, prior to this current adventure in Jython. What I am looking to do is return all zxJDBC errors, so I can identify & write try/except handling around those that I can deal with.

Relevant code is as follows:

##########################################################
# from http://forum.java.sun.com/thread.jspa?threadID=300557
#
# Author: SG Langer Jan 2007 translated the above Java to this
#       Jython class
# Purpose: Allow runtime additions of new Class/jars either from
#       local files or URL
######################################################
class classPathHacker(object):
import java.lang.reflect.Method
import java.io.File
import java.net.URL
import java.net.URLClassLoader
def addFile(self, s):
    f = self.java.io.File(s)
    u = f.toURL()
    a = self.addURL(u)
    return a
def addURL(self, u):
    sysloader = self.java.lang.ClassLoader.getSystemClassLoader()
    sysclass = self.java.net.URLClassLoader
    method = sysclass.getDeclaredMethod("addURL", [self.java.net.URL])
    a = method.setAccessible(1)
    jar_a = jarray.array([u], self.java.lang.Object)
    b = method.invoke(sysloader, [u])
    return u

tmp = classPathHacker()
tmp.addFile("/opt/sikuli/libs/mysql-connector-java-5.1.29-bin.jar")
from com.ziclix.python.sql import zxJDBC
db = zxJDBC.connect("jdbc:SERVER/DATABASE", "USER", "PASSWORD", "com.mysql.jdbc.Driver", CHARSET='iso_1')
b = db.cursor()
b.execute("SOME_SQL_CODE_GOES_HERE")
for row in b:
    data = str(row)
    <DO IRRELEVANT THINGS WITH SQL RETURN>
b.close()
db.close()

How would I structure the code to capture errors/exceptions?

I suspect there is some valuable information here for someone who knows enough Java to translate it to Jython.

score 0 · Accepted Answer · answered Jul 03 '14 at 16:27

What is missing are the try & except calls

Based on the above, specific exceptions can be called out if so desired, but otherwise all exceptions can be returned with:

##########################################################
# from http://forum.java.sun.com/thread.jspa?threadID=300557
#
# Author: SG Langer Jan 2007 translated the above Java to this
#       Jython class
# Purpose: Allow runtime additions of new Class/jars either from
#       local files or URL
######################################################
class classPathHacker(object):
import java.lang.reflect.Method
import java.io.File
import java.net.URL
import java.net.URLClassLoader
def addFile(self, s):
    f = self.java.io.File(s)
    u = f.toURL()
    a = self.addURL(u)
    return a
def addURL(self, u):
    sysloader = self.java.lang.ClassLoader.getSystemClassLoader()
    sysclass = self.java.net.URLClassLoader
    method = sysclass.getDeclaredMethod("addURL", [self.java.net.URL])
    a = method.setAccessible(1)
    jar_a = jarray.array([u], self.java.lang.Object)
    b = method.invoke(sysloader, [u])
    return u

tmp = classPathHacker()
tmp.addFile("/opt/sikuli/libs/mysql-connector-java-5.1.29-bin.jar")
from com.ziclix.python.sql import zxJDBC
db = zxJDBC.connect("jdbc:SERVER/DATABASE", "USER", "PASSWORD", "com.mysql.jdbc.Driver", CHARSET='iso_1')
try:
    b = db.cursor()
    b.execute("SOME_SQL_CODE_GOES_HERE")
    for row in b:
        data = str(row)
        <DO IRRELEVANT THINGS WITH SQL RETURN>
    b.close()
    db.close()
except:
    print("%s - [ERROR] %s \n" % (datetime.datetime.fromtimestamp(time.time()).strftime('%m-%d-%Y 5H:%M:%S'), sys.exc_info()[1]))

This would cause an error to print looking something like "07-03-2014 12:10:39 - [ERROR] cursor is closed", which can be further debugged from there.

Answer based on the official webpage for Jython Exception Handling & Debugging.

PS - Sorry to answer my own question - not sure if it's bad juju to do SO; but since I couldn't find another page with a similar problem, I thought others might appreciate the info.

Returning zxJDBC Errors in Jython or Sikuli?

1 Answers1