My problem is simple: in my XML data, a timestamp is provided as a long integer (number of milliseconds since the "the epoch"). When I do XSLT, I want to display it as a readable string, such as "Mon Nov 01 18:08:48 CDT 2010". After hours of struggle, I found: It's not so easy to get the job done with JDK 1.6 There are tons of garbage on the web in this space (suggestions, code snippets that simply don't work) Simple Xalan extension functions was the only resource that's somewhat informative. Even there some of the examples don't work. Below is a list of what worked and what didn't. This works: <xsl:stylesheet version="1.0" xmlns:xsl="h... This does not (providing long value to Date constructor): <xsl:stylesheet version="1.0" xmlns:xsl="h......

This note lists some of the different behaviors I found using different JSF implementations. In the simple JSF facelet example, I used Sun's reference implementation version 2.0.0-RC: <dependency> <groupId>javax.faces</gro... With this version, the DOCTYPE declaration is dropped when the page is rendered. It doesn't matter what DOCTYPE you declare in your templates, the facelet engine simply drops it. The problem with this is, your page is always displayed in quirks mode , despite your intentions to require standards compliant mode. The DOCTYPE problem is fixed in release 2.0.2-FCS . Change the dependency in pom.xml to: <dependency> <groupId>javax.faces</gro... and test again, you'll find that DOCTYPE is faithfully passed over to the browser (view source at browser). You can delete the DOCTYPE declaration in the xhtml template...

I built a very basic JSF application and deployed to Tomcat 7.0.22, but it failed with this error: Caused by: java.lang.ClassFormatError: Absent Code... That looks weird and I wasn't able to find a sensible explanation! So I copied the jsf-api-2.1.jar , which was downloaded from the java.net Maven repository by Maven, into a temp folder. And tested it with this simple program: public class ClassFormatErrorTest { public ... I also copied servlet-api.jar from Tomcat's lib folder to the temp folder. Sure enough it failed with the same error: C:\tmp>java -cp .;jsf-api-2.1.jar;servlet-api.jar ... But when I replaced the javax.faces.webapp.FacesServlet class with one I compiled from source, the error disappears! Conclusions: The jar file jsf-api-2.1.jar from java.net Maven repository is good for compilation only (cannot be used...

Here's a list of common TCP ports. You can find a more complete list here: http://www.gasmi.net/docs/tcp.html . Port Number Service Description 21 FTP File Transfer Protocol 22 SSH Secure Shell 23 Telnet Telnet remote login 25 SMTP Simple Mail Transfer Protocol 70 gopher Gopher 79 finger Finger 80 HTTP Hyper Text Transfer Protocol (WWW) 88 Kerberos Kerberos authentication 94 tivoli Tivoli Object Dispatcher 110 pop3 Post Office Protocol Version 3 123 ntp Network Time Protocol 137 netbios NetBIOS Name Service 138 netbios NetBIOS Datagram 139 netbios NetBIOS Session 143 imap Internet Message Access Protocol 161 snmp Simple Network Management Protocol 162 snmptrap SNMP trap 194 irc Internet Relay Chat Protocol 389 ldap Lightweight Directory Access Protocol 443 https Secure HTTP 445 SMB MS Server Message...

A task that a Java developer does so frequently is to find out where a certain class can be found - to resolve compilation errors, classpath issues, or version conflicts of the same class introduced by multiple class loaders. A long while back I wrote a simple Perl script to perform the task. Later I was informed that there are Swing based Jar Browser and Jars Browser . Then, there are a couple of shell one-liners: # one liner 1 find -name "*.jar" -print0 | xarg... But all of them share the same problem: if a class is in a jar nested in another jar, it cannot be found. Such is the case for a class inside a jar under the WEB-INF/lib directory of a...

I tried to find a GZIP compression servlet filter to compress a large log file that we send down to the browser. Most of the implementations I found were overly complicated and many buggy. This is a simple implementation that worked for me. The filter: package filter.demo; import java.io.*; i... Config web.xml : <filter> <filter-name>gzipFilter</filte... The ugly anonymous inner class could have been avoided if the servlet API did not insist on ServletResponse.getOutputStream returning the bogus ServletOutputStream class (instead of the plain OutputStream ). Additional Note: In an earlier version of this filter, the gzip headers were added in doFilter , like this: // This is NOT good! if (supportsGzip) { ... It turned out that the ServletResponse methods sendError bypasses the gzip...

JSTL string manipulation functions String manipulation functions are simple and self-evident. You just need to know that they exist. Test it Make these additions to the expanded test application : Create a new Java class StringManipulation : package jstl.demo.handler; import java.... Create a new JSP ( stringmanipulation.jsp ) under webapp : <%@ taglib uri="http://java.sun.com/jsp/jstl/c... Compile and package the WAR with: mvn package Deploy the WAR to a servlet container of your choice (for example, Tomcat or JBoss). Test the page with this URL (Tomcat/JBoss running on port 8080): http://localhost:8080/jstl-demo/demo/StringManipulation You may adjust the URL if your servlet container runs on a different port or the web app is bound to a different context root.

Parsing XML in Java is really simple: import java.io.*; import javax.xml.parsers.Docu... The parser implementation details are hidden behind the JAXP API. In case you want to know which parser implementation is used, this is what the JavaDoc for DocumentBuilderFactory.newInstance says: Use the javax.xml.parsers.DocumentBuilderFactory system property. Use the properties file " lib/jaxp.properties " in the JRE directory. This configuration file is in standard java.util.Properties format and contains the fully qualified name of the implementation class with the key being the system property defined above. The jaxp.properties file is read only once by the JAXP implementation and it's values are then cached for future use. If the file does not exist when the first attempt is made to read from it, no further attempts are made to...

This XML signature validator comes from the Apache XML Security project. It validates the signature according to the core validation processing rules . It does not verify that the key used to generate the signature is a trusted key. You can override the KeySelector class to make sure that the signing key is from a trusted store. import javax.xml.crypto.*; import javax.xml.cry...

Given a simple XML file like this: <?xml version="1.0"?> <root id="1"> ... Calling Document.getElementById returns null (surprisingly!): import java.io.*; import org.w3c.dom.*; impo... In fact the JavaDoc says something along the lines that getElementById returns the Element that has an ID attribute with the given value. An attribute with the name "ID" or "id" is not of type ID unless it is so defined. How is an attribute defined as an ID attribute ? With a DTD or schema. If you are not validating the XML, then the API is useless. So, what to do if you want to find an element for which the attribute named "id" has a given value? Several options were offered in GetElementById Pitfalls . One of them is to...