feat : Logger 설정 추가

* build : graphql-java-extended-scalars 의존성 추가

* feat : GraphQL 에서 기본적으로 지원하지 않는 Long, java.time 관련 타입 Scalars 생성 훅 설정 추가

* refactor : Long, LocalDateTime 타입 프로퍼티 추가

* feat : @GraphQLName 어노테이션 예제 코드 추가

놀이터(예제 코드 작성)/graphql-kotlin/build.gradle.kts

@@ -26,6 +26,7 @@ dependencies {
 	testImplementation("io.projectreactor:reactor-test")
 
 	implementation("com.expediagroup", "graphql-kotlin-spring-server", "6.0.0")
+	implementation("com.graphql-java:graphql-java-extended-scalars:18.1")
 }
 
 tasks.withType<KotlinCompile> {

놀이터(예제 코드 작성)/graphql-kotlin/src/main/kotlin/com/banjjoknim/graphqlkotlin/configuration/ExtendedScalarsConfiguration.kt

@@ -0,0 +1,107 @@
+package com.banjjoknim.graphqlkotlin.configuration
+
+import com.expediagroup.graphql.generator.hooks.SchemaGeneratorHooks
+import graphql.language.StringValue
+import graphql.scalars.ExtendedScalars
+import graphql.scalars.util.Kit.typeName
+import graphql.schema.Coercing
+import graphql.schema.CoercingParseLiteralException
+import graphql.schema.CoercingParseValueException
+import graphql.schema.CoercingSerializeException
+import graphql.schema.GraphQLScalarType
+import graphql.schema.GraphQLType
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import java.time.LocalDate
+import java.time.LocalDateTime
+import java.time.LocalTime
+import java.time.format.DateTimeFormatter
+import kotlin.reflect.KClass
+import kotlin.reflect.KType
+
+/**
+ * - [Extended Scalars for graphql-java](https://github.com/graphql-java/graphql-java-extended-scalars)
+ *
+ * - [Cannot use java.util.Date](https://github.com/ExpediaGroup/graphql-kotlin/discussions/1198)
+ *
+ * - [GraphQL Kotlin - Extended Scalars](https://opensource.expediagroup.com/graphql-kotlin/docs/schema-generator/writing-schemas/scalars/#common-issues)
+ *
+ * - [GraphQL Kotlin - Generator Configuration & Hooks](https://opensource.expediagroup.com/graphql-kotlin/docs/schema-generator/customizing-schemas/generator-config)
+ */
+@Configuration
+class ExtendedScalarsConfiguration {
+    /**
+     * 아래와 같이 Bean으로 Hook을 등록해주면 Schema Generator가 Schema를 생성할 때 이 Bean에 정의된 Hook을 이용해서 Schema를 만든다.
+     */
+    @Bean
+    fun extendedScalarsHooks(): SchemaGeneratorHooks {
+        return object : SchemaGeneratorHooks {
+            override fun willGenerateGraphQLType(type: KType): GraphQLType? {
+                return when (type.classifier as? KClass<*>) {
+                    Long::class -> ExtendedScalars.GraphQLLong
+                    LocalDateTime::class -> localDateTimeScalar()
+                    LocalTime::class -> ExtendedScalars.LocalTime
+                    LocalDate::class -> ExtendedScalars.Date
+                    else -> null
+                }
+            }
+        }
+    }
+
+    /**
+     * Bean으로 ScalarType을 등록해주지 않으면 어플리케이션 실행시 스키마를 구성하는 단계(스키마에 포함될 타입중에서 LocalDateTime 이 포함되어 있는 경우)에서 아래와 같은 예외가 발생한다.
+     *
+     * ```
+     * graphql.AssertException: All types within a GraphQL schema must have unique names. No two provided types may have the same name.
+     * No provided type may have a name which conflicts with any built in types (including Scalar and Introspection types). You have redefined the type 'LocalDateTime' from being a 'GraphQLScalarType' to a 'GraphQLScalarType'
+     * ```
+     *
+     * @see graphql.scalars.datetime.DateTimeScalar
+     */
+    @Bean
+    fun localDateTimeScalar(): GraphQLScalarType? {
+        val coercing = object : Coercing<LocalDateTime, String> {
+            override fun serialize(dataFetcherResult: Any): String {
+                return when (dataFetcherResult) {
+                    is LocalDateTime -> DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(
+                        LocalDateTime.from(dataFetcherResult)
+                    )
+                    is String -> DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(
+                        LocalDateTime.parse(dataFetcherResult)
+                    )
+                    else -> throw CoercingSerializeException(
+                        "Expected something we can convert to 'java.time.LocalDateTime' but was '" +
+                            "${typeName(dataFetcherResult)}'."
+                    )
+                }
+            }
+
+            override fun parseValue(input: Any): LocalDateTime {
+                return when (input) {
+                    is LocalDateTime -> input
+                    is String -> LocalDateTime.parse(
+                        input.toString(),
+                        DateTimeFormatter.ISO_LOCAL_DATE_TIME
+                    )
+                    else -> throw CoercingParseValueException(
+                        "Expected a 'String' but was '" + "${typeName(input)}'."
+                    )
+                }
+            }
+
+            override fun parseLiteral(input: Any): LocalDateTime {
+                if (input !is StringValue) {
+                    throw CoercingParseLiteralException(
+                        "Expected AST type 'StringValue' but was '${typeName(input)}'."
+                    )
+                }
+                return LocalDateTime.parse(input.toString(), DateTimeFormatter.ISO_LOCAL_DATE_TIME)
+            }
+        }
+        return GraphQLScalarType.newScalar()
+            .name("LocalDateTime")
+            .description("Custom LocalDateTime Scalar")
+            .coercing(coercing)
+            .build()
+    }
+}

놀이터(예제 코드 작성)/graphql-kotlin/src/main/kotlin/com/banjjoknim/graphqlkotlin/person/Person.kt

@@ -1,5 +1,9 @@
 package com.banjjoknim.graphqlkotlin.person
 
+import java.time.LocalDateTime
+
 data class Person(
     var name: String,
+    var age: Long? = 0L,
+    var birthDate: LocalDateTime = LocalDateTime.now()
 )

놀이터(예제 코드 작성)/graphql-kotlin/src/main/kotlin/com/banjjoknim/graphqlkotlin/person/PersonQuery.kt

@@ -1,9 +1,12 @@
 package com.banjjoknim.graphqlkotlin.person
 
+import com.expediagroup.graphql.generator.annotations.GraphQLDescription
 import com.expediagroup.graphql.generator.annotations.GraphQLIgnore
+import com.expediagroup.graphql.generator.annotations.GraphQLName
 import com.expediagroup.graphql.server.operations.Query
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.stereotype.Component
+import kotlin.random.Random
 
 @Component
 class PersonQuery(
@@ -17,6 +20,7 @@ class PersonQuery(
     private val personRepository: PersonRepository
 ) : Query {
 
+    @GraphQLDescription("get Person Instance")
     fun getPerson(name: String): Person = Person(name)
 
     /**
@@ -31,7 +35,12 @@ class PersonQuery(
      * If you are using custom data fetcher make sure that you extend SpringDataFetcher instead of the base FunctionDataFetcher to keep this functionallity.
      * ```
      */
+    @GraphQLDescription("find Person Instance")
     fun findPerson(@GraphQLIgnore @Autowired personRepository: PersonRepository, name: String): Person? {
         return personRepository.findPerson(name)
     }
+
+    @GraphQLDescription("@GraphQLName example")
+    @GraphQLName("somePerson")
+    fun randomPerson(name: String): Person = Person(name = name, age = Random.nextLong())
 }

놀이터(예제 코드 작성)/graphql-kotlin/src/test/kotlin/com/banjjoknim/graphqlkotlin/person/PersonQueryTest.kt

@@ -0,0 +1,99 @@
+package com.banjjoknim.graphqlkotlin.person
+
+import org.json.JSONObject
+import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.api.Nested
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.http.MediaType
+import org.springframework.test.web.reactive.server.WebTestClient
+
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+class PersonQueryTest(
+    @Autowired
+    private val webTestClient: WebTestClient
+) {
+
+    @DisplayName("getPerson Query Tests")
+    @Nested
+    inner class GetPersonTestCases {
+        @Test
+        fun `인자로 넣은 이름을 가진 Person 객체를 얻는다`() {
+            val query = """
+            query {
+              getPerson(name: "colt") {
+                name
+              }
+            }
+        """.trimIndent()
+            val json = JSONObject().put("query", query).toString()
+            webTestClient.post()
+                .uri("/graphql")
+                .accept(MediaType.APPLICATION_JSON)
+                .contentType(MediaType.APPLICATION_JSON)
+                .bodyValue(json)
+                .exchange()
+                .expectBody().json("""{"data":{"getPerson":{"name":"colt"}}}""")
+                .consumeWith {
+//                    assertThat(something...)
+                    println(it.responseHeaders)
+                }
+        }
+    }
+
+    @DisplayName("findPerson Query Tests")
+    @Nested
+    inner class FindPersonTestCases {
+
+        @Test
+        fun `메모리에 존재하는 Person 객체 중에서 인자와 이름이 일치하는 객체를 얻는다`() {
+            val query = """
+            
+            query {
+              findPerson(name: "banjjoknim") {
+                name
+              }
+            }
+
+        """.trimIndent()
+            val json = JSONObject().put("query", query).toString()
+            webTestClient.post()
+                .uri("/graphql")
+                .accept(MediaType.APPLICATION_JSON)
+                .contentType(MediaType.APPLICATION_JSON)
+                .bodyValue(json)
+                .exchange()
+                .expectBody().json("""{"data":{"findPerson":{"name":"banjjoknim"}}}""")
+                .consumeWith {
+//                    assertThat(something...)
+                    println(it.responseHeaders)
+                }
+        }
+
+        @Test
+        fun `인자와 이름이 일치하는 객체가 메모리에 없으면 null을 얻는다`() {
+            val query = """
+            
+            query {
+              findPerson(name: "invalid") {
+                name
+              }
+            }
+
+        """.trimIndent()
+            val json = JSONObject().put("query", query).toString()
+            webTestClient.post()
+                .uri("/graphql")
+                .accept(MediaType.APPLICATION_JSON)
+                .contentType(MediaType.APPLICATION_JSON)
+                .bodyValue(json)
+                .exchange()
+                .expectBody().json("""{"data":{"findPerson":null}}""")
+                .consumeWith {
+//                    assertThat(something...)
+                    println(it.responseHeaders)
+                }
+        }
+    }
+}

놀이터(예제 코드 작성)/spring-cloud-open-feign/.gitignore

@@ -0,0 +1,37 @@
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/

놀이터(예제 코드 작성)/spring-cloud-open-feign/README.md

@@ -0,0 +1,25 @@
+# Spring Cloud Open Feign
+
+## 프로젝트 구성
+
+- [Spring initializr](https://start.spring.io/) 에서 프로젝트 생성.
+- 아래 사진은 프로젝트 구성 Dependencies.
+
+![img.png](img.png)
+
+## 요구사항
+
+- [{JSON} Placeholder](https://jsonplaceholder.typicode.com/) 에서 게시글 목록을 조회한다.
+- [{JSON} Placeholder](https://jsonplaceholder.typicode.com/) 에서 게시글을 조회한다.
+
+## 참고자료
+
+- [Introduction to Spring Cloud OpenFeign](https://www.baeldung.com/spring-cloud-openfeign)
+- [Spring Cloud OpenFeign](https://spring.io/projects/spring-cloud-openfeign)
+- [Spring Cloud OpenFeign](https://cloud.spring.io/spring-cloud-openfeign/reference/html/)
+- [우아한 Feign 적용기](https://techblog.woowahan.com/2630/)
+- [Feign 좀 더 나아가기](https://techblog.woowahan.com/2657/)
+- [GitHub - OpenFeign/feign](https://github.com/OpenFeign/feign)
+- [Java Jackson JSON Library](https://kwonnam.pe.kr/wiki/java/jackson)
+- [{JSON} Placeholder](https://jsonplaceholder.typicode.com/)
+- [Spring Cloud Openfeign](https://brunch.co.kr/@springboot/202)

놀이터(예제 코드 작성)/spring-cloud-open-feign/build.gradle.kts

@@ -0,0 +1,47 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
+plugins {
+	id("org.springframework.boot") version "2.7.5"
+	id("io.spring.dependency-management") version "1.0.15.RELEASE"
+	kotlin("jvm") version "1.6.21"
+	kotlin("plugin.spring") version "1.6.21"
+	kotlin("plugin.jpa") version "1.6.21"
+}
+
+group = "com.banjjoknim"
+version = "0.0.1-SNAPSHOT"
+java.sourceCompatibility = JavaVersion.VERSION_11
+
+repositories {
+	mavenCentral()
+}
+
+extra["springCloudVersion"] = "2021.0.4"
+
+dependencies {
+	implementation("org.springframework.boot:spring-boot-starter-data-jpa")
+	implementation("org.springframework.boot:spring-boot-starter-web")
+	implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
+	implementation("org.jetbrains.kotlin:kotlin-reflect")
+	implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
+	implementation("org.springframework.cloud:spring-cloud-starter-openfeign")
+	runtimeOnly("com.h2database:h2")
+	testImplementation("org.springframework.boot:spring-boot-starter-test")
+}
+
+dependencyManagement {
+	imports {
+		mavenBom("org.springframework.cloud:spring-cloud-dependencies:${property("springCloudVersion")}")
+	}
+}
+
+tasks.withType<KotlinCompile> {
+	kotlinOptions {
+		freeCompilerArgs = listOf("-Xjsr305=strict")
+		jvmTarget = "11"
+	}
+}
+
+tasks.withType<Test> {
+	useJUnitPlatform()
+}

놀이터(예제 코드 작성)/spring-cloud-open-feign/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.5.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

놀이터(예제 코드 작성)/spring-cloud-open-feign/gradlew

@@ -0,0 +1,240 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

놀이터(예제 코드 작성)/spring-cloud-open-feign/gradlew.bat

@@ -0,0 +1,91 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

놀이터(예제 코드 작성)/spring-cloud-open-feign/settings.gradle.kts

@@ -0,0 +1 @@
+rootProject.name = "spring-cloud-open-feign"

놀이터(예제 코드 작성)/spring-cloud-open-feign/src/main/kotlin/com/banjjoknim/springcloudopenfeign/SpringCloudOpenFeignApplication.kt

@@ -0,0 +1,13 @@
+package com.banjjoknim.springcloudopenfeign
+
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.runApplication
+import org.springframework.cloud.openfeign.EnableFeignClients
+
+@EnableFeignClients
+@SpringBootApplication
+class SpringCloudOpenFeignApplication
+
+fun main(args: Array<String>) {
+	runApplication<SpringCloudOpenFeignApplication>(*args)
+}

놀이터(예제 코드 작성)/spring-cloud-open-feign/src/main/kotlin/com/banjjoknim/springcloudopenfeign/configuration/FeignConfiguration.kt

@@ -0,0 +1,56 @@
+package com.banjjoknim.springcloudopenfeign.configuration
+
+import com.fasterxml.jackson.databind.DeserializationFeature
+import feign.Logger
+import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder
+
+@Configuration
+class FeignConfiguration : Jackson2ObjectMapperBuilderCustomizer {
+    override fun customize(jacksonObjectMapperBuilder: Jackson2ObjectMapperBuilder) {
+        jacksonObjectMapperBuilder
+            .featuresToEnable(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL)
+            .featuresToDisable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+    }
+}
+
+/**
+ * For each Feign client, a logger is created by default.
+ *
+ * To enable logging, we should declare it in the application.properties file using the package name of the client interfaces:
+ *
+ * > logging.level.com.baeldung.cloud.openfeign.client: DEBUG
+ *
+ * Or, if we want to enable logging only for one particular client in a package, we can use the full class name:
+ *
+ * > logging.level.com.baeldung.cloud.openfeign.client.JSONPlaceHolderClient: DEBUG
+ *
+ * **Note that Feign logging responds only to the DEBUG level.**
+ *
+ * The ***Logger.Level*** that we may configure per client indicates how much to log:
+ * ```java
+ * public class ClientConfiguration {
+ *
+ *     @Bean
+ *     Logger.Level feignLoggerLevel() {
+ *         return Logger.Level.BASIC;
+ *     }
+ * }
+ * ```
+ *
+ * There are four logging levels to choose from:
+ *
+ * - NONE – no logging, which is the default
+ * - BASIC – log only the request method, URL and response status
+ * - HEADERS – log the basic information together with request and response headers
+ * - FULL – log the body, headers and metadata for both request and response
+ */
+@Configuration
+class LoggerConfiguration {
+    @Bean
+    fun feignLoggerLevel(): Logger.Level {
+        return Logger.Level.FULL
+    }
+}

놀이터(예제 코드 작성)/spring-cloud-open-feign/src/main/kotlin/com/banjjoknim/springcloudopenfeign/domain/Post.kt

@@ -0,0 +1,8 @@
+package com.banjjoknim.springcloudopenfeign.domain
+
+data class Post(
+    val userId: Long,
+    val id: Long,
+    val title: String,
+    val completed: Boolean
+)

놀이터(예제 코드 작성)/spring-cloud-open-feign/src/main/kotlin/com/banjjoknim/springcloudopenfeign/domain/PostClient.kt

@@ -0,0 +1,28 @@
+package com.banjjoknim.springcloudopenfeign.domain
+
+import org.springframework.cloud.openfeign.FeignClient
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.PathVariable
+
+/**
+ * Feign is a declarative web service client. It makes writing web service clients easier.
+ * To use Feign create an interface and annotate it.
+ * It has pluggable annotation support including Feign annotations and JAX-RS annotations.
+ * Feign also supports pluggable encoders and decoders.
+ * Spring Cloud adds support for Spring MVC annotations and for using the same HttpMessageConverters used by default in Spring Web.
+ * Spring Cloud integrates Eureka, as well as Spring Cloud LoadBalancer to provide a load-balanced http client when using Feign.
+ *
+ * 쉽게 말하면 RestTemplate, RestClient 등의 `HTTP Client`를 어노테이션으로 선언하여 사용하는 것이라 생각하면 된다.
+ * 인터페이스를 만들고 @FeignClient 를 선언하기만 하면 구현체는 런타임에 알아서 만들어진다.
+ *
+ * @see org.springframework.cloud.openfeign.FeignClient
+ */
+@FeignClient(value = "post", url = "https://jsonplaceholder.typicode.com/")
+interface PostClient {
+
+    @GetMapping("/posts")
+    fun findPosts(): List<Post>
+
+    @GetMapping("/posts/{postId}")
+    fun findPost(@PathVariable postId: Long): Post
+}

놀이터(예제 코드 작성)/spring-cloud-open-feign/src/main/kotlin/com/banjjoknim/springcloudopenfeign/domain/PostController.kt

@@ -0,0 +1,21 @@
+package com.banjjoknim.springcloudopenfeign.domain
+
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.PathVariable
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+class PostController(
+    private val postClient: PostClient
+) {
+
+    @GetMapping("/posts")
+    fun posts(): List<Post> {
+        return postClient.findPosts()
+    }
+
+    @GetMapping("/posts/{postId}")
+    fun post(@PathVariable postId: Long): Post {
+        return postClient.findPost(postId)
+    }
+}

놀이터(예제 코드 작성)/spring-cloud-open-feign/src/main/resources/application.yaml

@@ -0,0 +1,21 @@
+spring:
+  datasource:
+    url: jdbc:h2:mem:testdb;
+    driver-class-name: org.h2.Driver
+    username: sa
+    password:
+  jpa:
+    properties:
+      hibernate:
+        format_sql: true
+    hibernate:
+      ddl-auto: create-drop
+      naming:
+        physical-strategy: org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
+        implicit-strategy: org.hibernate.boot.model.naming.ImplicitNamingStrategyLegacyJpaImpl
+    show-sql: true
+logging:
+  level:
+    com:
+      banjjoknim:
+        springcloudopenfeign: DEBUG

놀이터(예제 코드 작성)/spring-cloud-open-feign/src/test/kotlin/com/banjjoknim/springcloudopenfeign/SpringCloudOpenFeignApplicationTests.kt

@@ -0,0 +1,13 @@
+package com.banjjoknim.springcloudopenfeign
+
+import org.junit.jupiter.api.Test
+import org.springframework.boot.test.context.SpringBootTest
+
+@SpringBootTest
+class SpringCloudOpenFeignApplicationTests {
+
+	@Test
+	fun contextLoads() {
+	}
+
+}