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Created by voodoo on December 08, 2011 08:52:40
Last update: December 08, 2011 08:52:40
I don't know if there's a fool proof way to find out which Linux distro you are running on, but here are some ways you can try:
cat /proc/version
cat /etc/issue
cat /etc/*release
lsb_release -a
Results on Ubuntu 11.10 oneiric:
$ cat /proc/version
Linux version 3.0.0-13-gene...
Results on Red Hat Enterprise Server:
$ cat /proc/version
Linux version 2.6.18-128.1....
Created by Fang on December 06, 2011 19:03:25
Last update: December 07, 2011 08:54:11
Our custom tag, as implemented in the previous note , is broken when a template is used.
Create a template file ( home-template.xhtml ):
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Stric...
and a test page that uses it ( home.xhtml ):
<?xml version="1.0" encoding="UTF-8"?>
<ui:comp...
Then request the page with URL: http://localhost:8080/facelet-demo/home.jsf?name=Jack .
You'll find that our hello tag works inside ui:repeat but fails to get the value defined by ui:param ! What's the problem? Our hello tag implementation evaluated the EL with the wrong EL context!
This is the corrected implementation:
package com.example;
import java.io.IOExcep...
Created by Fang on October 22, 2011 20:43:31
Last update: October 22, 2011 20:45:13
The only explanation of why some Java EE API classes are stripped off methods implementations I can find is this JBos forum post: What's the cause of this exception: java.lang.ClassFormatError: Absent Code? which also provides some workarounds for these crippled API classes. The explanation offered was: When one compiles, they want to run as well. By the way, we have been promoting full set of Java EE APIs which can only be used for compilation - they are stripped off method details. That way, user can't take those artifacts and try to use it in runtime. Honestly, I don't see any logic in those statements. This is the only place any such explanation is offered. Yes only from this JBos forum post! There's no public...
Created by Fang on October 22, 2011 19:51:05
Last update: October 22, 2011 20:31:48
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...
Created by freyo on September 09, 2011 11:43:36
Last update: September 09, 2011 11:45:45
When you run automated Android tests with Eclipse or from the command line, you get text output, which isn't good for reporting purposes. If you run a large set of test cases with automated build, the text report isn't very helpful. Fortunately, Android CTS generates test reports in XML with accompanying XSL to make it look nice in a browser. To run your own tests with Android CTS: Download Android CTS Make a new directory MyRepository under android-cts , alongside the existing repository directory. Copy host_config.xml from repository to MyRepository Create directory plans under MyRepository , add a test plan ( MyTests.xml ):
<?xml version="1.0" encoding="UTF-8"?> <TestPla... Create directory testcases under MyRepository . Copy TestDeviceSetup.apk from repository/testcases to MyRepository/testcases Under MyRepository/testcases , create a test...
Created by freyo on August 25, 2011 09:07:40
Last update: August 25, 2011 20:45:43
This is a list of built-in Android permission values: Permission Description Since API Level android.permission.ACCESS_CHECKIN_PROPERTIES Allows read/write access to the "properties" table in the checkin database, to change values that get uploaded. 1 android.permission.ACCESS_COARSE_LOCATION Allows an application to access coarse (e.g., Cell-ID, WiFi) location 1 android.permission.ACCESS_FINE_LOCATION Allows an application to access fine (e.g., GPS) location 1 android.permission.ACCESS_LOCATION_EXTRA_COMMANDS Allows an application to access extra location provider commands 1 android.permission.ACCESS_MOCK_LOCATION Allows an application to create mock location providers for testing 1 android.permission.ACCESS_NETWORK_STATE Allows applications to access information about networks 1 android.permission.ACCESS_SURFACE_FLINGER Allows an application to use SurfaceFlinger's low level features 1 android.permission.ACCESS_WIFI_STATE Allows applications to access information about Wi-Fi networks 1 android.permission.ACCOUNT_MANAGER Allows applications to call into AccountAuthenticators. Only the system can get this permission. 5 android.permission.AUTHENTICATE_ACCOUNTS...
Created by freyo on August 17, 2011 12:29:46
Last update: August 17, 2011 12:29:46
In Android.mk , you can define LOCAL_JARJAR_RULES like this:
LOCAL_JARJAR_RULES := $(LOCAL_PATH)/jarjar-rules.t...
and in jarjar-rules.txt define a rule like this:
rule org.bouncycastle.** com.android.@0
The build will change all org.bouncycastle to com.android.org.bouncycastle . Therefore, in your classes which are dependent on the library produced, the import statements should look like:
import com.android.org.bouncycastle...
Help for the jarjar utility (in prebuilt/common/jarjar/ ):
$ java -jar jarjar-1.0rc8.jar
Jar Jar Links - ...
Created by Dr. Xi on July 15, 2011 09:25:15
Last update: July 15, 2011 09:25:15
Some methods to search for a substring within a string:
To know that a substring indeed exists within a string:
boolean found = wholeString.contains(substring);
To find where the substring is contained:
int index = wholeString.indexOf(substring);
If the substring is regex:
boolean match = wholeString.matches(".*" + substri...
Case insensitive match: convert both whole string and substring to lowercase, then compare. Or, use case insensitive flag for regex.
Test code:
import java.util.regex.*;
public class Stri...
Created by alfa on June 02, 2011 15:26:37
Last update: June 02, 2011 15:26:37
While doing some Java reflection code, I noticed the method Class.isSynthetic() , which the JavaDoc says returns " true if and only if this class is a synthetic class as defined by the Java Language Specification". However, there's no definition of "synthetic class" in the JLS ! The only thing that I can find that remotely resembles a definition is in the JVM spec , where it defines the synthetic attribute : "The Synthetic attribute is a fixed-length attribute in the attributes table of ClassFile (§4.1), field_info (§4.5), and method_info (§4.6) structures. A class member that does not appear in the source code must be marked using a Synthetic attribute." By this definition, a default constructor, which does not appear in the source code, should...
Created by alfa on May 25, 2011 21:17:18
Last update: May 25, 2011 21:18:04
The Java regex expression \B matches a non-word boundary, which is anything other than a word boundary.
import java.util.regex.*;
public class NonW...
Output:
p1 match: word at 40
p1 match: word at 83
...
