Because it’s hard to use JavaMail alone, use Apache Commons Email. build.gradle dependencies { compile 'javax.mail:mail:1.4.7' compile 'org.apache.commons:commons-email:1.5' } Kotlin import org.apache.commons.mail.util.MimeMessageParser import java.io.ByteArrayInputStream import java.io.IOException import java.util.Properties import javax.mail.MessagingException import javax.mail.Session import javax.mail.internet.InternetAddress import javax.mail.internet.MimeMessage ... fun parse(rawMimeMessage: String): MailData? = ByteArrayInputStream(rawMimeMessage.toByteArray()).use { try { val session = Session.getDefaultInstance(Properties()) val parser = MimeMessageParser(MimeMessage(session, it)) parser.parse() MailData( parser.from, parser.replyTo ?: parser.from, parser.to.map { (it as InternetAddress).address }, parser.cc.map { (it
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Pros of JWT validate the access token without accessing the database get user ID etc from access token without accessing database Pros of JWT-RS Even outside the source of the access token, verify validity and acquire user ID etc using public key How to generate RSA key $ openssl genrsa 4096 > prikey.txt $ # Generate public key $ openssl rsa -pubout < prikey.txt > pubkey.txt $ # Convert secret
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To save passwords, BCrypt is better than SHA hash Pros Protect against rainbow table attacks (Generate different hashes with the same password) Resistant to brute-force attacks Setup Updating your dependencies // build.gradle dependencies { compile "org.springframework.security:spring-security-core" } Usage ... user.passwordHash = BCryptPasswordEncoder().encode(password) user.save() fun login(userId:String, password: String): Boolean { ... if(!BCryptPasswordEncoder().matches(password, user.passwordHash)){ return false } return true }
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In AWS (ECS / EC 2), when using database password or RSA secret key, It is good to obtain from AWS Secrets Manager Terraform settings AWS Secrets Manager Create AWS Secrets Manager with terraform resource "aws_secretsmanager_secret" "something" { name = "${var.app_name}/${terraform.workspace}/something" kms_key_id = "${aws_kms_key.main.key_id}" } resource "aws_secretsmanager_secret_version" "something" { secret_id = "${aws_secretsmanager_secret.something.id}" secret_string = "{}" lifecycle { ignore_changes = ["secret_string"] } } IAM Role Add permissions to read/write values to
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Truncate All Tables（for Testing） /// Delete Tables Component @Component class DataCleaner( private val dataSource: DataSource, private val entityManager: EntityManager ) { private var tables: List<String>? = null fun deleteAll() { dataSource.connection.use { con -> // Safety if (!con.metaData.url.contains("unittest")) { throw Exception("DANGER!!!") } if (tables == null) { tables = con.metaData.getTables(con.catalog, null, null, arrayOf("TABLE")).use {
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Add @EnableScheduling to the Application class @SpringBootApplication @EnableScheduling class Application { companion object { @JvmStatic fun main(args: Array<String>) { SpringApplication.run(Application::class.java, *args) } } } Add @Sccheduled to the background method @Service class BackgroundRunner { @Scheduled(fixedDelay = 1000 * 60 * 60) // Run every hour fun doSomething() { ... } }
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@Entity data class User( var id: Long, var name: String?, var age: Int, ... ) class UserSummary(var id:Long, var name:String?) interface UserRepository : JpaRepository<User, Long> { fun findOneById(id: Long): User? fun <VIEW> findOneById(id: Long, type: Class<VIEW>): VIEW? fun <VIEW> findByIdIn(ids: List<Long>, type: Class<VIEW>): List<VIEW> // Using @Query failed to narrow the select column by passing type // @Query("from org.example.User where id in :ids") // fun <VIEW>findByIds(@Param("ids") ids: List<Long>, type:Class<VIEW>): List<VIEW>
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Unlike Java, in the case of Kotlin, using JDBC directly does not become too redundant Data acquisition method 3 patterns EntityManager @Component class Clazz1( private val entityManager: EntityManager ){ fun procSomething() { val rows = entityManager.createNativeQuery(""" select id, field1 from table1 """).let { q -> q.resultList } } } JpaRepository @Entity data class AnyData( val id: Long, val field1: String ) interface AnyDataRepository : JpaRepository<AnyData, Long> { } @Component class
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