1, Android Studio hit Jar package

1. Create an AndroidStudio project

Note the following Package Name

2. Enter the Android Studio project

Select the Project Flies option and find app-> src-> main-> Next is your own folder-
find the last folder mine is unitytoandroid Right click to create a Java class (if there is a Java class here-it may be your AndroidStudio Before downloading, see if AndroidStudio is downloaded in the lower right corner.) After downloading, you can create a Java class.
Name it yourself

3. Start writing code

4. Packed to the most important step

(1)-find the build.gradle file to open

(2) -It is like this after opening

(3) -Modified to the following figure

apply plugin: 'com.android.library' 加入

    task makeJar(type: Copy) {
        //删除存在的
        delete 'build/libs/Test.jar'
        //设置拷贝的文件
        from('build/intermediates/aar_main_jar/release/')
        //打进jar包后的文件目录
        into('build/libs/')
        //将classes.jar放入build/libs/目录下
        //include ,exclude参数来设置过滤
        //（我们只关心classes.jar这个文件）
        include('classes.jar')
        //重命名
        rename ('classes.jar', 'Test.jar')
    }
    makeJar.dependsOn(build)

(3) -After editing, click the Sync Now button in the upper right corner

(4) -After waiting for the run to succeed, we can see that there is a play button in front of the task method and click the play button to run

(5) -After the operation is over

You can see that there is an extra build folder (if it runs successfully-there is no such folder-go to the app directory to create a build / libs folder)
to find the directory, copy this file and copy it to the Unity Plugins / Android / libs / under

5. Create a script

using UnityEngine;
using UnityEngine.UI;
//在电脑上运行可能出不来效果  需要打包到手机上测试
public class TestUnity : MonoBehaviour
{
    public Text text;

    public AndroidJavaObject androidJavaobject;
    
    private void Start()
    {
        androidJavaobject = new AndroidJavaObject("imsdk.u3d.unitytoandroid.Test");//这个是androidStudio创建的包名加上自己创建的脚本
    }

    public void intClick()
    {
        text.text = androidJavaobject.Call<int>("testInt").ToString();
        Debug.Log(androidJavaobject.Call<int>("testInt"));
    }
    public void stringClick()
    {
        text.text = (androidJavaobject.Call<string>("testString"));
        Debug.Log(androidJavaobject.Call<string>("testString"));
    }
    public void setStringClick()
    {
        text.text = androidJavaobject.Call<string>("testSetString", "sss");
        Debug.Log(androidJavaobject.Call<string>("testSetString", "sss"));
    }
}

6. Project address

https://gitee.com/Aaron_han/AndroidStudio_jar