How to use the J2OBJC Annotations framework in the Java library
How to use J2OBJC Annotations framework in the Java library
J2OBJC is a powerful tool that can convert the Java code into Objective-C code to achieve the reuse of the Java code on the iOS platform.In the development process, we may encounter the need to convert the Java class library into Objective-C libraries.The J2Objc Annotions framework is an important part of the J2OBJC tool. It provides us with a way to win the bidding and control conversion process in the Java class library.This article will introduce how to use the J2Objc Annotations framework in the Java library.
The J2Objc Annotions framework is usually used to mark the elements that need to be converted in the Java class library, and can specify some options in the conversion process by annotating.Before using the J2Objc Annotations framework, we need to introduce the dependencies of the J2Objc tools and the Annotations framework.
First, the dependencies of the introduction of J2Objc and Annotations frameworks were introduced in the construction configuration file of the project.Assuming that we use Gradle to build a project, we can add dependencies in the following ways in the `build.gradle` file:
groovy
dependencies {
implementation 'com.google.j2objc:j2objc-annotations:1.3'
implementation 'com.google.j2objc:j2objc-gradle-plugin:2.9'
}
After the dependencies are introduced, we can start using the J2Objc Annotations framework in the Java library.The following is an example:
import com.google.j2objc.annotations.ObjectiveCName;
import com.google.j2objc.annotations.Property;
import com.google.j2objc.annotations.Weak;
public class MyClass {
@ObjectiveCName("someMethod:")
public static void someMethod(String arg) {
// Method implementation
}
@Property
@ObjectiveCName("name")
private String mName;
@Weak
@ObjectiveCName("delegate")
private Delegate mDelegate;
// Other member variables and methods
}
In the above examples, we used the name of the `@octivecname` annotations to specify the names in Objective-C in the Java method, class member variables and other elements.For example, use the method of using the Java method to name the java method as `SOMEMETHOD` and the method of converting the java method and the method of converting the java method.In this way, this method can be called directly in Objective-C.
We also use the member variables that need to generate attributes in Objective-C in Objective-C.In Objective-C, the access method of attributes will be generated automatically.
The `@weak` annotation is used to mark member variables that need to be modified in Objective-C in Objective-C.This is very useful for preventing cycle references.
In addition to the annotations in the above examples, the J2Objc Annotations framework also provides other annotations for the marking and control conversion process.You can refer to the official documents as needed to further understand the use of these annotations.
After using the J2Objc Annotations framework in the code, we can use the J2OBJC tool to convert the code.The specific conversion process can refer to the instructions of the official documentation and tools.
To sum up, the steps of using the J2Objc Annotations framework in the Java library are as follows: as follows:
1. Introduction to the dependencies of J2Objc and Annotations framework.
2. Mark and control the conversion process with annotations provided by the Annotations framework in the Java library.
3. Use the J2OBJC tool to convert the Java code into Objective-C code.
4. Use the converted code in the Objective-C project.
I hope this article can help you understand how to use the J2Objc Annotations framework in the Java library.By using the J2OBJC Annotations framework reasonably, we can more flexibly control the process of converting the Java code into the Objective-C code, thereby improving the reuse and efficiency of the code.
