Develop Reference

Error when adding RxPresso to project

I got this error message when trying to add RxPresso(https://github.com/novoda/rxpresso/) to my project:
Warning:Conflict with dependency 'io.reactivex:rxjava'. Resolved versions for app (1.1.9) and test app (1.0.14) differ. See http://g.co/androidstudio/app-test-app-conflict for details.
I'm currently using rxjava 1.1.9. How can I add RxPresso in my project?
Thx a lot

To avoid any problems with RxJava and Android Support Libraries version, go to your app/build.gradle file and in dependencies section paste:
androidTestCompile ('com.novoda:rxpresso:0.2.0') {
exclude group: 'com.android.support', module: 'support-annotations'
exclude group: 'io.reactivex'
}

You can explicitly tell Gradle which version to use, by adding into your build.gradle next snippet
configurations.all {
// check dependency tree with gradlew :app:dependencies
// avoid wildcard '+' dependencies used at 3rd libraries forcing them to exact version
resolutionStrategy.force "io.reactivex:rxjava:1.1.9"
}

Compiling ion library without android-support to avoid conflict

I'm trying to compile the ion library into my project like this:
compile 'com.koushikdutta.ion:ion:2.1.6'
but the problem is its dependencies there is also support-v4 library that I already imported in a subproject and that I cannot remove from there.
Is there a way to compile/import the ion library without taking the support library? I remember there was a sort a way like:
compile 'com.koushikdutta.ion:ion:2.1.6:support-v4'
to remove it but I don't remember the exact syntax and I can't find anything about it... any idea?

Found! :)
You need to add before the android declaration, in the gradle file:
configurations {
all*.exclude group: 'com.android.support', module: 'support-v4'
}

cannot access DialogStyle

After updating android-support library to 22.2.0 project stopped compiling.
error: cannot access DialogStyle
class file for android.support.v4.app.DialogFragment$DialogStyle not found
Consult the following stack trace for details.
com.sun.tools.javac.code.Symbol$CompletionFailure: class file for android.support.v4.app.DialogFragment$DialogStyle not found
Can't find how to work around this issue.
Previously used version was 22.1.1

#takoli's answer works in most cases but if you have other dependencies that silently include support-v4 or if you are too lazy to explicitly exclude support-v4 everywhere here is another solution.
compile 'com.android.support:appcompat-v7:22.2.0'
compile 'com.android.support:recyclerview-v7:22.2.0'
compile 'com.android.support:mediarouter-v7:22.2.0'
// Force stable version of support-v4
compile ('com.android.support:support-v4:22.1.1') {
force = true
}
Update:
AndroidAnnotations released a new version 3.3.2 that resolves this issue. If you are using AndroidAnnotations update to 3.3.2 and use the 22.2.0 support libraries without forcing the old version of support-v4. For more information see this thread

Here is a couple workarounds that worked for us:
Workaround 1 (some people see a NPE with this, some don't)
I just found a TEMPORARY workaround... till appcompat fixes this issue:
Create the following package in your project src/main/java
android.support.v4.app
Create the following new file:
DialogFragment$DialogStyle.java
Contents
package android.support.v4.app;
// todo remove this file when fixed in appcompat (https://code.google.com/p/android/issues/detail?id=175086)
public #interface DialogFragment$DialogStyle {
}
Workaround 2 (bit more ugly, but less potential for a build issue)
I found another work-around.... a bit more ugly... but has gotten us around this issue (including the NPE on the above work-around) till appcompat 22.2 is fixed.
Create the following package in your project src/main/java
android.support.v4.app
Copy the Google v4 FragmentDialog.java code
https://android.googlesource.com/platform/frameworks/support/+/refs/heads/master/v4/java/android/support/v4/app/DialogFragment.java
Rename the class (to something like TempFragmentDialog). You will get a "Duplicate" class error if you don't rename the class.
Any FragmentDialog, in your project, that has #Inject will need to extend your copy of the FragmentDialog (example: public class MyFragmentDialog extends TempFragmentDialog)

Try this, it resolved my issue:
compile ('com.android.support:appcompat-v7:22.2.0') {
exclude module: 'support-v4' }
compile ('com.android.support:recyclerview-v7:22.2.0') {
exclude module: 'support-v4' }
compile ('com.android.support:cardview-v7:22.2.0') {
exclude module: 'support-v4' }
compile ('com.android.support:design:22.2.0') {
exclude module: 'support-v4' }
// and exclude support-v4 from other dependencies as well that might include it
// finally add it, but avoid version 22.2.0...
compile ('com.android.support:support-v4:22.1.1')
There is no need to manually add the support-v4 library to your libs directory, the last import ensures that the right version is included in your project.
BTW all of this workaround is not your fault, blame others :)

I am using the work around found here https://code.google.com/p/android/issues/detail?id=175086#c9
I modified my build.gradle file to say the following in the dependencies section:
compile fileTree(include: ['*.jar'], dir: 'libs')
compile ('com.android.support:appcompat-v7:22.2.0') {
exclude module: 'support-v4'
}
compile ('com.android.support:gridlayout-v7:22.2.0') {
exclude module: 'support-v4'
}
compile ('com.android.support:cardview-v7:22.2.0') {
exclude module: 'support-v4'
}
compile ('com.android.support:design:22.2.0') {
exclude module: 'support-v4'
}
You will also have to exclude it from any other dependencies that use the support library like dagger or facebook.
Then, I added the android-support-v4.jar file found in $ANDROID_HOME/extras/android/support/v4 to my libs directory, as that file does seem to have DialogFragment$DialogStyle.
Now, my build is fully working again, but I still hope this can get fixed soon.

Simply put, this is a bug in support library version 22.2.0
Just upgrade to the next update 22.2.1, works like a charm.

Just in case to not to skip an answer: here is also a discussion about this problem https://github.com/excilys/androidannotations/issues/1435
BTW, do you use Android Annotations in a project where this problem exists ?

It happens if you are using android.support.v4.app.DialogFragment.
Try to use android.app.DialogFragment instead.

gradle dependency error in android

In the following build.gradle, I added the configuration section to avoid double inclusion of support libraries. Support libraries are used in the main project and in the dependent projects like facebook sdk. Without the configuration section, I get "UNEXPECTED TOP-LEVEL EXCEPTION". Adding that configuration makes the error go away and the app all works fine.
Now, I'm trying to add RecyclerView to my app and I get RecyclerView class not found while inflating the recyclerview (although it builds ok). If I remove the facebook SDK and configuration section, the recyclerview works just fine.
Question: What changes can I make to the build.gradle to make the facebook SDK work and RecyclerView work? In other words, why is the config section excluding v7 when it is only supposed to exclude v4?
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
compile 'com.android.support:support-v4:+'
compile 'com.android.support:support-v13:+'
compile 'com.android.support:cardview-v7:+'
compile 'com.android.support:recyclerview-v7:+'
compile 'com.google.android.gms:play-services:4.4.52'
compile project(':facebook-3.15')
compile project(':parse-1.5.1')
compile project(':viewpagerindicator-2.4.1')
}
configurations {
// to avoid double inclusion of support libraries
all*.exclude group: 'com.android.support', module: 'support-v4'
}

If you're having a dependency conflict with the v4 support library, you can just exclude it from one of the libraries via the gradle script:
compile ('com.android.support:recyclerview-v7:+') {
exclude module: 'support-v4'
}

I fixed that adding:
compile ('com.facebook.android:facebook-android-sdk:3.22.0#aar'){
exclude module: 'support-v4'
}

Found a solution to this:
Removed the config section in the build.gradle that excludes support-v4
It turns out that .aar files are basically a zip, so removed the support-v4 jar from the dependency .aar library (using 7-zip).
And now, I don't get the top-level exception and at the same time able to use recyclerview-v7.
If you are using dependency projects instead of .aar files, try removing the support-v4.jar files in the dependency projects before compiling.
Shouldn't the gradle build tool be intelligent enough to exclude the duplicate packages rather than having the users go thru this kind of workarounds and headaches?

How to use Mina with slf4j on Android Gradle build?

I am getting a DEX error (already added classes..) since mina is depending on slf4j-api, and slf4j-android is also carrying some of the slf4j-api internally.
Is there a way to solve this while still using gradle external (maven based) dependencies?
dependencies {
compile('org.apache.mina:mina-core:2.0.7')
compile 'org.slf4j:slf4j-android:1.6.1-RC1'
}

The answer seems to be the ability to exclude a module (sub-dependency):
dependencies {
compile('org.apache.mina:mina-core:2.0.7') {
exclude module: 'slf4j-api'
}
compile 'org.slf4j:slf4j-android:1.6.1-RC1'
}