Multiple versions of same library

问题:

I have project A, which used to have module A1, that used dagger v. 1.2.2. Now I'd like to add to project A, module A2, that has dependency on dagger v. 2.0. But I can't because these two dagger libs are in conflict. Can I approach somehow multiple versions of library in different android modules?

回答1:

You can't have both.

You need to exclude the conflicting libraries from dependencies:

configurations {
    all*.exclude group: 'com.google.android', module: 'support-v4'
}

dependencies {
    compile 'com.android.support:support-v4:13.0.0'
}

From: https://github.com/stephanenicolas/robospice/issues/161

OR

dependencies {
    compile("org.gradle.test.excludes:api:1.0") {
        exclude module: 'shared'
    }
}

From: https://docs.gradle.org/current/userguide/dependency_management.html #52.4.7

回答2:

Why do you wan to t keep both of them? I don't think if it is possible, you should go for one library only. And here you should use the latest one, as I think if the latest one is added the older one doesn't matter. Check out these links if they help you with dagger...

Dagger dependencies when overriding graph with mock module causes NoClassDefFoundError

How to use dagger in a android library project

Dagger dependencies when overriding graph with mock module causes NoClassDefFoundError

回答3:

You need to exclude the dagger v. 1.2.2 library and let the dagger v. 2.0. The latter normally will be back compatible. Look at the gradle doc about how to exclude specific dependency. https://docs.gradle.org/current/userguide/dependency_management.html