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...

Mapping Java objects to Jackson JSON is pretty simple. But if you name a JSON field wrong, you'll get the "Unrecognized field ... (Class ...), not marked as ignorable" error. The rule for mapping a Java bean attribute name to a JSON field name is: lower all leading capital letters until the first lower case letter . For example, this Java class: package com.example; public class Person { ... maps to this JSON string: { "firstName": "Jane", "lastName": "... Test code: package com.example; import java.net.URL; ...

This was the error message: [ERROR] sun.security.validator.ValidatorExceptio... The certificate was actually signed by Verisign, but somehow failed to pass Java cert validation. To resolve the problem: Download the cert from the server (with RetrieveSSLCert , for example) Import the certificate into the keystore: $ keytool -import -trustcacerts -alias myserver -f... Define MAVEN_OPTS : $ export MAVEN_OPTS='-Djavax.net.ssl.trustStore=/h... The quotes must exist for the value of MAVEN_OPTS , and the path must be absolute ( ~/etc/mavenKeyStore.jks does not work).

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......

The stack trace is like this: java.lang.IllegalArgumentException: Component prop... You get this error because you are using the class attribute with a JSF UI component, for which the class attribute cannot be altered. Of course you meant CSS class, not Java class! You can use the styleClass attribute instead of the class attribute. The styleClass attribute becomes the class attribute when the component is rendered. If you can add a tag handler to the UI component, you can alias class to styleClass , which will allow you to use the class attribute on the UI component: import javax.faces.view.facelets.*; pub...

The Android unit test framework is based on JUnit 3 , not JUnit 4. Test cases have to extend junit.framework.TestCase or a subclass (such as android.test.InstrumentationTestCase ). Tests are identified by public methods whose name starts with test , not methods annotated with @Test (as in JUnit 4). An Android test suite is packaged as an APK, just like the application being tested. To create a test package, first you need to identify the application package it is testing. Google suggests to put the test package source in a directory named tests/ alongside the src/ directory of the main application. At runtime, Android instrumentation loads both the test package and the application under test into the same process. Therefore, the tests can invoke methods on...

This code snippet import java.util.*; public class UncheckedCast ... fails with a compilation error and a warning: $ javac -Xlint:unchecked UncheckedCast.java Unc... Because List<String> is not a reifiable type, the Java Runtime does not have enough information to verify the type or do the type casting. This is fixed by changing List<String> to List<?> (or to the raw type List ): public static void main(String[] args) { Ob...

Parameterized types are considered different at compile time but not at runtime. This program fails compilation because List<Foo> is not the same as List<Bar> : import java.util.ArrayList; import java.util.Li... Error: $ javac SameErasure.java SameErasure.java:8: do... This also fails because List<Foo> and List<Bar> are considered the same: import java.util.ArrayList; import java.util.Li... Error: $ javac SameErasure.java SameErasure.java:11: n...

This is an odd-ball content provider in that it doesn't provide database records, but provides a resource as a stream. It can be used to provide media files or XML resources. Start the project with: tools/android create project --package com.android... Create assets directory and add an XML file ( assets/demo.xml ): <? xml version="1.0" encoding="UTF-8"?> <people... Edit the layout ( res/layout/main.xml ): <?xml version="1.0" encoding="utf-8"?> <LinearL... Edit src/com/android/cptest/Dummy.java : package com.android.cptest; import java.io.... Add content provider ( src/com/android/cptest/XmlResource.java ): package com.android.cptest; import java.io.... Update AndroidManifest.xml : <?xml version="1.0" encoding="utf-8"?> <manifes... Add this section to the end of build.xml : <target name="-package-resources"> <ech... Build and install: ant install Screenshot: Remove the Dummy activity ( AndroidManifest.xml ): <?xml version="1.0" encoding="utf-8"?> <manifes... Create a new project for...

An XML schema is a definition of XML files, in XML. It plays the same role as old-time DTDs. Overall, an XML schema file looks like this: <schema attributeFormDefault = (qualified | u... The attribute meanings: targetNamespace : The name space targeted by the current schema definition. It can be any URI. id and version : For user convenience, the W3C spec defines no semantics for them. xml:lang : Natural language identifier defined by RFC 3306 . attributeFormDefault and elementFormDefault : Set default values for the form attribute for attribute and element declarations. blockDefault and finalDefault : Set default values for the block and final attributes for attribute and element declarations. The W3C defined some built-in datatypes . Examples of primitive datatypes are: string ,...