I would like to know the minimum Android API level AndroidAnnoatations supports ? I could not find any info on their website .
regards,
Felix T
I think there is NO specific minimum Android API Level that AndroidAnnotations can work with.
Since it's a compilation tool, I mean it's related with the Java files and it's related not with Android API.
If you build an Android project with AndroidAnnotations, then some intermediate java files will be generated, which will be the final java file for Java compiler, and that's all. It's just used for convinience of your development. The generated apk file will not have information about AndroidAnnotations - it's something like a conversion tool (shorter exprssion to long complicated expression, which is not visible to you).
I think that you can use AndroidAnnotation from Android API Level 1.
Maybe some of the annotations cannot be used in Android API 1 project, but even if such case happens, just removing only that specific annotation in your .java file will make it work.
Related
In the context of C++ toolchain, I am trying to understand the difference of the concept between cc_toolchain_suite and register_toolchains, to me it seems they achieve the same purpose: select a toolchain based on command line parameters.
See https://docs.bazel.build/versions/master/toolchains.html for register_toolchains
See https://docs.bazel.build/versions/master/cc-toolchain-config-reference.html for cc_toolchain_suite
Can someone please help understand the subtlety behind these 2 concepts?
TL;DR The cc_toolchain_suite is part of the legacy toolchain configuration system. It still exists in Bazel because the migration to the new API is not complete. The register_toolchains is part of the newer, unified toolchain API. When possible use register_toolchains instead of cc_toolchain_suite/--*crosstool_top
Originally the concept of a 'toolchain' was not standardised in Bazel, so a Java toolchain would be implemented very differently than a cc toolchain.
Before the unified starlark toolchain API, cc toolchains were specified in proto-text formatted 'CROSSTOOL' files.
With the introduction of the platforms API and the unified toolchains API, the concepts in the CROSSTOOL files were converted almost 1:1 to the new unified platforms/toolchains starlark API. This was mostly to ensure that there was compatibility between the old/new API's.
One of the concepts in the older 'CROSSTOOL' configuration system was a 'toolchain suite', that allowed you to define a group of toolchains targeting different CPU's (This was before the platforms API was introduced).
As far as I understand the only reason that cc_toolchain_suite is still a part of Bazel's starlark API is that some of the apple/android toolchains have not yet been completely migrated across.
Here are a few examples of where I've opted to using the newer register_toolchains approach. Note that these toolchains do not use cc_toolchain_suite anymore.
How to create a class dynamically in a Blackberry project that uses Eclipse plugin?
My requirement: Suppose on click of a button a new class with a given name should be created. Methods and fields should be added and
then I should make use of that class
object. Is this possible in Blackberry?
Below are the steps I have done.
Get third party jars like ASM, javassist
Try to use them in project
but, I am getting verification errors when deploy to the device. So, is there a native api in RIM or any other alternative?
BlackBerry Java does not support the full set of reflection capabilities that you would expect in Standard Java (J2SE).
So, you won't be able to dynamically create a class, add methods, and then call them.
For the most part, BlackBerry is Java 1.3. If you tweak your development environment, you can get access to some newer features at compile time. But, in terms of the runtime code, you're limited to 1.3.
Javassist is based on Java APIs that don't exist in the 1.3 runtime that BlackBerry has, so it won't be of much help :(
Hopefully, someone else will chime in, but I don't know that this is something that's possible on BlackBerry Java.
I have read an article from Xamarin, and came across a particular computer science word : Ahead of Time.
According to some google search result, this AOT does not allow for code generation during run time.
Does it mean, it does not support dynamic stuff?
I know this question may stupid and I have 0 knowledge in IOS, hopefully can get some answer from here. thanks
First, what is the definition of dynamic? For the general public, dynamic code mean the application can change functionality at run-time. For the iOS platform, the binaries are signed to prevent malware. And Apple don't like apps that can load functionality at run-time.
An ahead-of-time (AOT) compiler has nothing to do with dynamic code per se. It's has to do with intermediate language that are just-in-time compilation (JIT). The biggest example of intermediate language is Java bytecode; compile once, run anywhere. When a Java application is executing, the compiled code is JIT to native machine code. AOT compiler is just doing it ahead of time, to save time.
For the iOS platform, Xcode compiles Objective-C to a native binary for the device.
Another way of looking at this is with an example...
In .Net, you can use the Reflection.Emit namespace to generate and compile code at runtime.
Eg you could create an "IDE" with a textbox that accepts C#. When you click a button that C# could be compiled by the .Net framework into a custom library that's loaded dynamically or a fully-fledged executable which is launched as a new process.
This is insanely powerful when combined with the rest of the System.Reflection namespace. You can examine objects at runtime and compile custom code based on any criteria you like.
That said... The problems usually outweigh the benefits in most cases. Mainly, it's a massive security issue, especially when running on a consumer device.
It would be possible to create an app that wouldn't have anything close to malicious code, get it audited by apple, then have the app download code from your webserver, compile it, and execute it. This new code wouldn't be audited...
There really is no good reason to be doing this in a consumer app.
Is there any migration analysers available for MonoTouch ?
I have seen one for Mono, but not for MonoTouch.
Short answer: No, there is none at the moment.
Long answer
The situation is a bit different from Mono. In general you test a complete and compiled (against a specific version of the framework) .NET application with MoMA, to get a report of what pieces are missing (or incomplete) in Mono that could affect the execution of your application on other platforms (e.g. OSX and Linux).
Testing a complete applications for MonoTouch would reports tons of issues - since the UI toolkit is totally different. E.g. anything about System.Windows.Forms, WPF... would always missing.
However if your assemblies are already split into (something like) an MVC design it would be possible to test some (the non-UI parts) of them against definitions based on the MonoTouch base class library.
Finally if someone has an immediate need (or looking for a nice project) MoMA is available as open source and the evaluation versions of MonoTouch contains all the assemblies needed to build the definitions files. A bit of extra filtering could make this into a very nice tool.
Alternative
You can see a list of the assemblies that are part of MonoTouch and some platform restrictions (compared to .NET) you should be aware.
When i compiled my application in blackberry it shows the following error.
generics are not supported in -source 1.3
(use -source 5 or higher to enable generics)
how to solve this
Java 1.3 is barbaric and no one should ever have to suffer its indignities. Fortunately, there is a solution!
Generics, enums, changing return signature in overrides, and pretty much everything that makes java usable was introduced in java 1.5. (see http://en.wikipedia.org/wiki/Java_version_history). Fortunately, most of java 1.5 was designed to be backwards compatible and not require JVM / bytecode changes. (or maybe this was unfortunate, as it lead Java's implementation of generics to be much weaker than C#. just try creating a generic class with static methods / fields that use the generic parameter)
This IBM article does a good job of explaining the background:
http://www.ibm.com/developerworks/java/library/j-jtp02277.html
But this JVM similarity allowed for creation of tools such as:
http://retrotranslator.sourceforge.net/
This is the section from my Ant buildfile that calls retrotranslator:
< java jar="${transformer.jar.exe}"
fork="true"
classpath="${epic-framework.dir}/tools/retrotranslator-runtime13-1.2.9.jar:${epic-framework.dir}/tools/retrotranslator-runtime-1.2.9.jar"
args="-srcjar ${build.dir}/classes5.jar -target 1.3 -destjar ${build.dir}/classes5to3.jar"
/>
Run the converted jar through preverify.exe and then give it to rapc.exe and you will have a working Blackberry app written with Java 1.5.
Edit: I missed a key detail in my original post. In addition to being Java 1.3, the Blackberry class hierarchy is missing many classes that would normally be a part of a Java SE 1.3 JDK. The one you will hit first is StringBuilder -- javac transforms ("string" + "otherstr" + "blah blah") into StringBuilder.append("string").append("otherstr").append("blah blah"). That class doesn't exist on BB, so you break. However, BB has StringBuffer, so writing an adapter between the two is pretty easy. The one catch is that BB disallows apps from adding classes into java.*. This can be very effectively fixed in the build process: 1) build your app against Java 1.5 w/ java.lang.StringBuilder on the classpath, 2) string transform java.lang.Stringbuilder (and everything else in your compat shim) to live in com.mycorp.java.lang.StringBuilder and build it into a JAR file. 3) Use that JAR file w/ retrotranslator and retrotranslator will update all bytecode references to java.lang.StringBuilder so that they now point to com.mycorp.java.lang.StringBuilder. Now you have a java 1.3 compatible bytecode that can be run on a Blackberry.
If anyone is interested in this stuff, contact me. I could look into open sourcing the compat library I have.
This is a limitation of J2ME, which uses a subset of the J2SE (no collections, reflection, etc.) and a Java language level of 1.3. Any code written for J2SE will most likely need to be manually ported.
It seems the JDK5 is not yet supported.
Same question was asked on the blackberrry forum but about enum support:
Sadly, the BlackBerry api is very behind in terms of Java versioning. There's no Generics, no Maps, no Enums - it's based around JDK 1.3.
I believe there is no way of enabling this feature within your BlackBerry app. If you find one, I'd be very interested to hear about it.