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Written by: Stanko Milosev

Category: Android

Published: 06 March 2022

Last Updated: 12 April 2022

Hits: 1859

• kotlin

Example how to start new Empty activity, add library to Gradle, and create JSON with GSON.

First start "Empty Activity":

In next step in my case I have choosen language Kotlin, Minimum SDK API 21:

In Android -> Gradle Scripts -> build.gradle:

I have added:

    implementation 'com.google.code.gson:gson:2.9.0'

Now my dependecies look like:

dependencies {
    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.appcompat:appcompat:1.4.1'
    implementation 'com.google.android.material:material:1.5.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
    implementation 'com.google.code.gson:gson:2.9.0'
}

Go to File -> Sync Project with Gradle Files:

In MainActivity write something like:

internal class Albums {
    var title: String? = null
    var message: String? = null
    var errors = arrayOf<String>()
    var total: String? = null
    var total_pages = 0
    var page = 0
    var limit: String? = null
}

and

val albums = Albums()
albums.title = "Free Music Archive - Albums"
albums.message = ""
albums.total = "11259"
albums.total_pages = 2252
albums.page = 1
albums.limit = "5"

val builder = GsonBuilder()
val gson: Gson = builder.create()
System.out.println(gson.toJson(albums))

My MainActivity now looks like:

package com.example.myapplication

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import com.google.gson.Gson
import com.google.gson.GsonBuilder

internal class Albums {
    var title: String? = null
    var message: String? = null
    var errors = arrayOf<String>()
    var total: String? = null
    var total_pages = 0
    var page = 0
    var limit: String? = null
}

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val albums = Albums()
        albums.title = "Free Music Archive - Albums"
        albums.message = ""
        albums.total = "11259"
        albums.total_pages = 2252
        albums.page = 1
        albums.limit = "5"

        val builder = GsonBuilder()
        val gson: Gson = builder.create()
        System.out.println(gson.toJson(albums))
    }
}