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Created by Dr. Xi on April 16, 2014 15:40:09    Last update: April 16, 2014 15:40:09
The "with" statement makes it easy to open a file, use it then finally close it, without explicitly coding with a " try...finally " block. Example: >>> import yaml >>> with open("app.yaml") as f:... More info: Understanding Python's "with" statement
Created by Dr. Xi on June 21, 2011 15:54:00    Last update: June 22, 2011 11:33:09
Demo code for CSV parsing with SuperCSV parser . Java code: import*; import java.util.List; imp... Test with a simple CSV file: psmith01,CLASS2B,Peter Smith 1,YEAR2,1,N,ADVANCED,... The parser worked correctly: Line 1 has 11 values: |psmith01| |CLASS2B|... Test with a more complicated CSV file: "psmith01 abc", "CLASS2B " , " Peter... The parser messed up on all three lines: Line 1 has 5 values: |psmith01 abc| |CLASS... Using two lines input: "psmith01 abc", "CLASS2B " , " Peter... It generates an exception: Line 1 has 5 values: |psmith01 abc| |CLASS... Add a new line in item two: "One", "Two ", "Three" Result: Line 2 has 3 values: |One| |Two | |...
Created by Dr. Xi on March 02, 2011 11:39:18    Last update: March 09, 2011 12:19:30
Some peculiarities about Java PrintWriter: PrintWriter never throws any exceptions. From JavaDoc : Methods in this class never throw I/O exceptions, although some of its constructors may. The client may inquire as to whether any errors have occurred by invoking checkError(). When error occurs, you'll never know anything more than that it occured, because checkError returns boolean. When a character is out of the range of the character encoding of the PrintWriter, it prints a question mark (?). But this is not an error. Test code: import*; public class TestPrintWri... Latin1 test result: java TestPrintWriter iso-8859-1 | od -bc 000000... UTF-8 test result: java TestPrintWriter utf-8 | od -bc 0000000 141... Also, the constructor throws a FileNotFoundException when you try to write to a...
Created by Dr. Xi on October 26, 2010 16:07:40    Last update: October 26, 2010 16:07:40
This is a more generic version, which can be expanded to accommodate additional file signatures. import*; import java.util.*; pu...
Created by Dr. Xi on October 23, 2008 03:54:04    Last update: October 23, 2008 03:57:44
Add validator plugin in struts-config.xml <struts-config> . . . ... Set validate="true" on action form <struts-config> <!-- ========== Form Bean De... Add validation rules in validation.xml <?xml version='1.0' encoding='windows-1252'?> <... If you override validate , make sure super.validate is called. package com.example; import javax.servlet.h... Read the documentation:
Created by Dr. Xi on October 06, 2008 22:48:08    Last update: October 06, 2008 22:50:11
A first attempt would be to create an input file like this: userid password shell_command1 shell_... and feed the lines to the telnet client: cat telnet_input.txt | telnet remote_host #... However, you'll learn soon enough that it doesn't work. You get output like this: Trying Connected to bash... What's happening? The telnet client depleted all input before the remote host had a chance to respond. Since there's no more input, the telnet client initiated to close the connection. Adding a delay between the commands makes it work: (echo userid sleep 10 echo password ... How much time to sleep between commands is just guesswork. You can use Expect to provide more control over the automated session: #!/usr/bin/expect # timeout script aft......