Analysis of the application case analysis of the Multidex framework in the Java library
Analysis of the application case analysis of the Multidex framework in the Java library
Summary:
As Android applications continue to increase, the number of methods for application is also increasing.When the number of methods exceeds the 65536 limit of the DEX file, the compiler will not be able to generate effective Dex files.To solve this problem, Google provides a framework called Multidex, allowing applications to continue working normally when the number of method number is limited.This article will introduce the application cases of the Multidex framework in the Java class library and provide some Java code examples.
introduction:
The complexity of Android applications is constantly increasing, and developers need to use many types of libraries to meet functional needs.The Java code in these libraries is usually compiled as a DEX file to run in Android applications.However, the DEX file of Android applications has a limit on the number of methods, and exceeding this limit will cause the compiler to be unable to generate effective dex files.This is a common problem, especially for large applications and the application of many third -party libraries.
Background and question:
DEX (Dalvik Executable) is an executable file format for Android applications, which contains all Java classes and methods applied.The size of the DEX file is mainly determined by the number of Java classes and methods used.When the number of methods in the DEX file exceeds 65536, the compiler will not be able to generate effective DEX files, which will cause the application to collapse or not work properly.
solution:
To solve the problem limit of the DEX method, Google provides a framework called Multidex.The Multidex framework allows the application to continue working normally when the number of 65536 methods is limited.
Application case analysis:
Below is a simple Java library application case analysis, showing how to use the Multidex framework in the Java library.
1. First, make sure your Android project introduces the Multidex library.Add the following dependencies to the project's Build.gradle file:
implementation 'androidx.multidex:multidex:2.0.1'
2. Create a custom Application class, and call the Multidex.install method in the onCreate method of this class. The example code is as follows:
import android.app.Application;
import androidx.multidex.MultiDex;
public class MyApplication extends Application {
@Override
protected void onCreate() {
super.onCreate();
MultiDex.install(this);
}
}
3. Update AndroidManifest.xml file, add the custom Application class to the application tag:
<application
android:name=".MyApplication"
...
</application>
4. If your application is already greater than 65536 methods, the compiler will generate multiple DEX files.In this case, you need to adjust the build.gradle file to ensure that all DEX files are loaded correctly.Add the following configuration to the DefaultConfig block:
android {
defaultConfig {
...
multiDexEnabled true
}
}
5. In your Java library, make sure you do not have more than 6,5536 methods.
As mentioned above, the process of using the Multidex framework in the Java library is very simple.By adding the Multidex.Install method to the onCreate method of the custom Application class, the application will continue to work normally when the number of DEX method is limited.
Summarize:
The Multidex framework provides an effective means to solve the problem of DEX method limit for Android application developers.By introducing the Multidex library and calling the Multidex.Install method in the custom Application class, developers can ensure that the application can continue to work normally when the number of 65536 methods is limited.This is especially important for the complex applications of a large number of libraries.
references:
- https://developer.android.com/studio/build/multidex
