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Created by Fang on April 16, 2012 12:58:35
Last update: April 16, 2012 12:58:35
To implement a JSP custom tag with dynamic attributes (for example, to pass-thru arbitrary attributes not handled by the JSP tag):
Set the dynamic-attributes element to true in the TLD:
<tag>
<name>mark</name>
<tag-class>c...
The tag handler must implement javax.servlet.jsp.tagext.DynamicAttributes :
package com.example.jsp;
import java.io.*;
...
Created by Fang on November 21, 2011 13:49:11
Last update: November 21, 2011 13:49:11
In the test for the simple taglib example , I used a literal string for the name attribute:
<my:hello name="Jack"/> What happens if the name attribute contains EL expresson? For example: <my:hello name="#{param['name']}"/> If EL works, the tag should take the value of the " name " request parameter and print it out. But the tag as implemented in the simple taglib example prints the literal string: Hello #{param['name']}! I am FaceletTag. In order to make a tag to recognize EL, we have to use TagAttribute.getValue(FaceletContext ctx) instead of TagAttribute.getValue() . The latter returns the literal value of the attribute. The HelloTagHandler should be changed to: package com.example; import java.io.IOExcep... Rebuild the taglib and test with a URL like this: http://localhost:8080/facelet-test/?name=Jack The tag will print:...
Created by magnum on September 27, 2011 09:32:18
Last update: September 27, 2011 09:33:04
Use tcpdump to monitor traffic on a network: To print all incoming and outgoing packets on host 192.168.0.1 :
tcpdump host 192.168.0.1 To print all incoming and outgoing IP packets on host firebird : tcpdump ip host firebird To write raw packets to a file, rather than parsing and printing them out: tcpdump ip host firebird -w /tmp/firebird.pcap To listen on interface eth0 (without this, tcpdump listens on the lowest numbered, configured up interface except loopback): tcpdump -i eth0 ip Use switch -X for more verbose output: tcpdump -i eth0 ip -X host 192.168.0.1 Outgoing from 192.168.0.1 : tcpdump -i eth0 ip -X src host 192.168.0.1 Incoming to 192.168.0.1 : tcpdump -i eth0 ip -X dst host 192.168.0.1 More verbose output: tcpdump -i eth0 tcp -vvX host 192.168.0.1...
Created by freyo on July 29, 2011 16:04:45
Last update: July 29, 2011 16:04:45
To start the Settings application:
# am start -n com.android.settings/.Settings
St...
To start the Browser :
# am start -n com.android.browser/.BrowserActivity...
To start the phone dialer:
# am start tel:210-385-0098
Starting: Intent { ...
Help for am command:
# am
usage: am [subcommand] [options]
...
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 java.io.*; 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 mak on March 04, 2011 14:17:32
Last update: March 04, 2011 14:18:35
To create a zipfile in python:
Code:
#!/usr/local/bin/python
import zipfile
#...
Test
unzip -l test.zip
Archive: test.zip
Lengt...
To read a zipfile in python:
Code:
#!/usr/local/bin/python
import zipfile
#...
Created by Dr. Xi on September 17, 2010 21:29:47
Last update: September 17, 2010 21:31:43
With JBoss (Tomcat?), the servlet container always appends the default charset ISO-8859-1 to the Content-Type header of a JSP response. For example, if you are using JSP to render PDF and put the following declaration at the top of the JSP:
<%@ page contentType="application/pdf"%> These would be the headers in the HTTP response (notice that charset=ISO-8859-1 was appended to Content-Type ): HTTP/1.1 200 OK Server: Apache-Coyote/1.1 X-... And the output would be truncated a few bytes before non-ASCII characters were encountered, without any error messages ! Maybe you don't intend to output binary files with JSP, but still your response would be truncated without warning if the page happens to contain any non-ASCII characters (when the charset is the default charset=ISO-8859-1 ). However, if you...
Created by Dr. Xi on January 08, 2010 03:53:37
Last update: January 08, 2010 03:54:56
This is an Ant custom task to merge Properties files I lifted from http://marc.info/?l=ant-user&m=106442688632164&w=2 , with some minor bug fixes.
Example usage:
<taskdef name="mergeProperty" classname="ant.task....
Implementation:
package ant.task.addon;
import java.io.Buff...
Created by Dr. Xi on December 04, 2009 04:33:05
Last update: December 04, 2009 04:33:05
Variable Meaning $_ The default or implicit variable. @_ Within a subroutine the array @_ contains the parameters passed to that subroutine. $a, $b Special package variables when using sort() $<digit> Contains the subpattern from the corresponding set of capturing parentheses from the last pattern match, not counting patterns matched in nested blocks that have been exited already. $. Current line number for the last filehandle accessed. $/ The input record separator, newline by default. $| If set to nonzero, forces a flush right away and after every write or print on the currently selected output channel. Default is 0 (regardless of whether the channel is really buffered by the system or not; $| tells you only whether you've asked Perl explicitly to flush after...
Created by Dr. Xi on October 06, 2008 23:31:56
Last update: October 06, 2008 23:35:08
Use file.write instead of print .
Python 2.5.1 (r251:54863, Mar 7 2008, 04:10:12)
...
