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Created by Dr. Xi on August 15, 2012 08:55:15    Last update: August 15, 2012 08:55:15
From Java JSSE documentation : The generic Java dynamic debug tracing support is accessed with the system property java.security.debug , while the JSSE-specific dynamic debug tracing support is accessed with the system property javax.net.debug . The javax.net.debug property value must specify either all or ssl , optionally followed by debug specifiers. Examples : To get a list of debugging options: java -Djavax.net.debug=help MyApp To view all debugging messages: java -Djavax.net.debug=all MyApp To view the hexadecimal dumps of each handshake message (the colons are optional): java -Djavax.net.debug=ssl:handshake:data MyApp To view the hexadecimal dumps of each handshake message, and to print trust manager tracing (the commas are optional): java -Djavax.net.debug=SSL,handshake,data,trustman... A detailed debugging example: Debugging SSL/TLS Connections
Created by Dr. Xi on June 06, 2009 18:31:44    Last update: June 25, 2012 12:37:35
You can use the system call from the os module to execute an external program: >>> import os >>> os.system(the_command_line_st... However, the path to the executable contains a space character, the system call treats the strings after the first space as arguments, causing an error. Python doc recommends the use of the subprocess module: The subprocess module provides more powerful facilities for spawning new processes and retrieving their results; using that module is preferable to using this function. For example, using wget to get the google home page: >>> from subprocess import Popen, PIPE >>> (out... or >>> import subprocess >>> subprocess.call(['cur...
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 Dr. Xi on May 02, 2011 15:59:37    Last update: February 25, 2012 09:16:37
This code snippet gets the default keystore used by the Java keytool and displays the list of aliases along with the key type (certificate or private key). import java.io.File; import java.io.FileInputSt... The default keystore used by the above code is: $HOME/.keystore .
Created by voodoo on January 03, 2012 08:41:21    Last update: February 16, 2012 15:50:06
This is the command to print all regular files in the src folder but excluding all files within the .svn folders: $ find src -name .svn -prune -o -type f -print where -o is the or operator. Define a shortcut: ff () { find $1 -name .svn -prune -o -...
Created by voodoo on February 16, 2012 13:35:38    Last update: February 16, 2012 13:35:57
The C shell allows you to define aliases with arguments: \!^ passes the first argument, \!* passes all arguments. Examples from http://unixhelp.ed.ac.uk : alias print 'lpr \!^ -Pps5' alias print 'lp... In ksh or bash you cannot define alias with arguments. Use function instead.
Created by woolf on December 11, 2011 13:38:58    Last update: December 11, 2011 13:38:58
Install usb.essentials . Package usbutils is optional. # opkg update # opkg install kmod-usb2 # opk... Install usb printer support: # opkg install kmod-usb-printer Install p910nd print server: # opkg install p910nd Edit /etc/config/p910nd : config p910nd option device /dev... Configure firewall to allow port 9100 ( /etc/config/firewall ): # Allow printer con... If clients are connecting from wan then the first line should be: option src wan Enable automatic start of print server when router boots: #/etc/init.d/p910nd enable Restart router: # reboot
Created by Fang on November 14, 2011 20:50:51    Last update: November 22, 2011 09:06:10
This facelet fragment will never print anything: <ui:repeat var="person" value="#{myBean.theJTeam}"... because the test condition always returns false, even though the person var is not null. The same happens even when I define another variable with ui:param : <ui:repeat var="person" value="#{myBean.theJTeam}"... What's happening? The c:if test condition is evaluated before the ui:repeat tag had a chance to set the value! Both facelet ui tags and JSTL c tags are evaluated at the Render Response phase of the JSF lifecycle. But within the Render Response cycle, there are two sub-phases (so to speak): the first builds the UI element tree, the second renders the UI tree. The JSTL c:if tag is evaluated when the tree is built, but the facelet ui:repeat tag is evaluated when the UI...
Created by Fang on November 08, 2011 20:55:00    Last update: November 21, 2011 18:19:44
In the simple taglib example , I used a tag handler class to implement a taglib. This is an example to implement a taglib with a UI component. The purpose is to use a custom tag to split a string and print each part in a separate paragraph, i.e., print <p>john</p> <p>steve</p> <p>mike</p> with custom tag <my:foreach> : <my:foreach var="who" value="john steve mike"> ... These are the files: pom.xml <project xmlns="http://maven.apache.org/POM/4.0.0"... src/main/java/com/example/UIForeash.java : package com.example; import java.io.IOExcep... src/main/resources/META-INF/faces-config.xml : <?xml version="1.0" encoding="UTF-8"?> <faces-c... src/main/resources/META-INF/foreach.taglib.xml : <?xml version="1.0" encoding="UTF-8"?> <facelet... How to use: Put the JAR file generated by the above project in the WEB-INF/lib folder of the web app. If the web app is a Maven project, just add the taglib project as a dependency:...
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:...
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