day19, day20

1. room 만들다 생긴 오류 수정

android AppDatabase_Impl does not exist 라는 에러가 발생.

KAPT란.
Kotlin에서 Annotation처리를 위해서 KAPT(Kotlin Annotation Processing Tool)을 제공
Project 내부에서 Hilt, Room, Databinding 같은 library가 사용된다면 필요

Kotlin은 kotlinc로 컴파일되기 때문에 기존에 Java로 작성된 Annotation Process로는 Kotlin의 Annotation이 제대로 처리되지 않음.


https://kotlinlang.org/  의 Kotlin Gradle 

plugins {
    kotlin("kapt") version "1.6.10"
}
...
dependencies {
    kapt("groupId:artifactId:version")
}

https://kotlinlang.org/  의 groovy Gradle 

plugins {
    id "org.jetbrains.kotlin.kapt" version "1.6.10"
}
...
dependencies {
    kapt 'groupId:artifactId:version'
}

 

몰라서 이렇게 했는데 됨. (다른 것들과 통일서 있게)

 

plugins {
    id 'com.android.application'
    id 'kotlin-android'
    id 'kotlin-kapt'
}
...
kapt "androidx.room:room-compiler:$room_version"

 

 

2. 전체소스

앱시작할 때 : db!!.contactsDao().getAll() //select
리스트 클릭했을 때 db?.contactsDao()?.delete(contacts = contacts) //delete
플러스 버튼을 눌렀을 때 : db?.contactsDao()?.insertAll(contact) //DB에 추가

 

build.gadle

plugins {
    id 'com.android.application'
    id 'kotlin-android'
    id 'kotlin-kapt'
}

android {
    compileSdk 31

    defaultConfig {
        applicationId "com.example.room_test"
        minSdk 26
        targetSdk 31
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }

    viewBinding{
        enabled true
    }
}

dependencies {

    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.appcompat:appcompat:1.4.0'
    implementation 'com.google.android.material:material:1.4.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.2'
    testImplementation 'junit:junit:4.+'
    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'

    def room_version = "2.3.0"

    implementation "androidx.room:room-runtime:$room_version"
    annotationProcessor "androidx.room:room-compiler:$room_version"
    kapt "androidx.room:room-compiler:$room_version"

}

 

 

AppDatabase.kt

package com.example.room_test

import android.content.Context
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase

@Database(entities=[Contacts::class], version=1, exportSchema = false)
abstract class AppDatabase : RoomDatabase(){

    abstract fun contactsDao() : ContactsDao

    companion object{
        private var instance:AppDatabase? = null

        @Synchronized
        fun getInstance(context:Context):AppDatabase?{
            if(instance == null){
                instance = Room.databaseBuilder(
                    context.applicationContext,
                    AppDatabase::class.java,
                    "database-contacts"
                )
                .allowMainThreadQueries()
                .build()
            }
            return instance
        }
    }
}

 

 

Contacts

package com.example.room_test

import androidx.room.Entity
import androidx.room.PrimaryKey


@Entity(tableName = "tb_contacts")
data class Contacts (
    @PrimaryKey(autoGenerate = true) val id:Long,
    var name:String,
    var tel:String
)

 

ContactsDao.kt

package com.example.room_test

import androidx.room.Entity
import androidx.room.PrimaryKey


@Entity(tableName = "tb_contacts")
data class Contacts (
    @PrimaryKey(autoGenerate = true) val id:Long,
    var name:String,
    var tel:String
)

 

ContactsListAdapter.kt

package com.example.room_test

import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.example.room_test.databinding.ItemContactsBinding



class ContactsListAdapter(private val itemList:List<Contacts>) : RecyclerView.Adapter<ContactsViewHolder>() {

    interface OnItemClickListener{
        fun onClick(v: View, position:Int)
    }

    private lateinit var itemClickListener : OnItemClickListener

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ContactsViewHolder {
        val binding = ItemContactsBinding.inflate(LayoutInflater.from(parent.context), parent, false)
        return ContactsViewHolder(binding)
    }

    override fun onBindViewHolder(holder: ContactsViewHolder, position: Int) {
        val item = itemList[position]
        holder.itemView.setOnClickListener{
            itemClickListener.onClick(it, position)
        }
        holder.bind(item)
    }

    override fun getItemCount(): Int {
        return itemList.size
    }

    fun setItemClickListener(itemClickListener:OnItemClickListener){
        this.itemClickListener = itemClickListener;
    }

}


class ContactsViewHolder(val binding:ItemContactsBinding): RecyclerView.ViewHolder(binding.root){
    fun bind(item:Contacts){
        binding.tvName.text = item.name
        binding.tvTel.text = item.tel
    }
}

 

 

MainActivity.kt

package com.example.room_test

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import com.example.room_test.databinding.ActivityMainBinding
import java.util.*

class MainActivity : AppCompatActivity() {
    val TAG = "MainActivity"
    var db : AppDatabase? = null
    var contactsList = mutableListOf<Contacts>()

    private lateinit var binding:ActivityMainBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        db = AppDatabase.getInstance(this)

        val savedContacts = db!!.contactsDao().getAll() //select
        if(savedContacts.isNotEmpty()){
            contactsList.addAll(savedContacts)
        }

        val adapter = ContactsListAdapter(contactsList)
        adapter.setItemClickListener(object:ContactsListAdapter.OnItemClickListener{
            override fun onClick(v: View, position: Int) {
                val contacts = contactsList[position]

                db?.contactsDao()?.delete(contacts = contacts) //delete
                contactsList.removeAt(position)
                adapter.notifyDataSetChanged()
            }
        })
        binding.rcv.adapter = adapter

        binding.mPlustButton.setOnClickListener {
            val random = Random()
            val numA = random.nextInt(1000)
            val numB = random.nextInt(10000)
            val numC = random.nextInt(10000)

            val rndNumber = String.format("%03d-%04d-%04d",numA,numB,numC)

            val contact = Contacts(0, "New $numA", rndNumber) //Contacts 생성
            db?.contactsDao()?.insertAll(contact) //DB에 추가
            contactsList.add(contact) //리스트 추가

            adapter.notifyDataSetChanged() //리스트뷰 갱신

        }
    }
}