diff --git a/docs/chapter7/Ch07Keyword.txt b/docs/chapter7/Ch07Keyword.txt
new file mode 100644
index 0000000..27361b5
--- /dev/null
+++ b/docs/chapter7/Ch07Keyword.txt
@@ -0,0 +1,162 @@
+1. DTO
+- 계층 간 데이터를 교환하기 위해서 만든 객체
+- 데이터 객체를 Service, Controller 등으로 보낼 때/DB에서 데이터를 받아 전송할 때 사용
+- [클라이언트-Controller-Service-Repository-DB] 모든 단에서 DB의 원본데이터가 움직이는 게 아님
+- 중간의 [Controller - Service - Repository] 각 단계에서 데이터를 옮길 때는 원본 데이터, 엔티티 대신 DTO를 사용 == DTO에는 엔티티의 변수 중 그 때 그 때 필요한 것만 골라서 넣어 놓는다
+  ---> 외부에 노출되면 안 되거나 노출할 필요가 없는 정보를 배제함
+
+(1) dto 사용 X, 엔티티를 그대로 응답으로 넘겨주는 경우
+- 엔티티가 변경되어 새로운 필드가 추가되거나 기존의 필드가 삭제되는 상황 발생
+--> 요구사항이 변경되어 person 테이블에 address라는 필드가 추가되는 경우, login API처럼 address 필드가 필요 없는 상황에는 불필요한 데이터가 전송되는 격
+
+2. converter
+- entity to dto
+- 엔티티 생성
+- repository에서 받아온 엔티티를 dto로 변환
+- DB에 저장할 때는 DTO -> Entity로 변호환
+
+3. converter 사용 위치
+DB -> Repostiory -> Service -> Controller -> Client 과정을 데이터가 전달될 때
+
+(1) Service에서 dto 생성
+- Service 안에서 converter 동작, dto 리턴
+- 장점: Controller에 Entity 노출X -> 불필요한 데이터는 보이지X -> 보안 good
+- 단점: api 하나의 controller, service, repository를 각기 다른 사람이 만드는 경우, controller를 작업하는 사람은 dto만 볼 수 있음
+
+(2) Controller에서 dto 생성
+- Service에서 entity 리턴
+- Controller에서 converter 동작
+- 장점: Service는 dto를 다룰 때보다 더 넒은 범위의 데이터를 다룰 수 있음, 다수의 컨트롤러에서 동일한 엔티티가 필요한 경우에 재사용 용이
+
+4. @Builder
+- 빌더 패턴을 적용할 객체에 @Builder 어노테이션 달기
+- 객체를 생성할 때 필드 이름으로 값 세팅
+- 필드 순서 상관X
+- e.g.
+Review.builder()
+                .reviewContent(request.content())
+                .userStar(request.userStar())
+                .userYear(request.userYear())
+                .build();
+
+5. @NoArgsConstructor(accss = AccessLevel.PROTECTED)
+- Lombok 라이브러리
+- 파라미터가 없는 기본 생성자(@Entity에서도 만들어주긴 하지만 PROTECTED 설정하기 위해서 사용)
+- 클래스에 생성자가 없어도 인스턴스를 생성
+@NoArgsConstructor
+public class Person{
+	private String name;
+	private Integer age;
+}
+
+public class Person{
+	private String name;
+	private Integer age;
+
+	public Person() { }
+}
+- 기본 생성자의 접근 제어를 PROTECTED로 설정
+--> 기본 생성자의 무분별한 생성을 방지(불완전한 객체가 생성되지 않도록)
+- 
+* access = AccessLevel.PRIVATE 도 있음
+
+
+6. @AllArgsConstructor
+- Lombok 라이브러리
+- 모든 필드 값을 파라미터로 받는 생성자를 생성
+@AllArgsConstructor
+public class Person{
+	private String name;
+	private Integer age;
+}
+
+public class Person{
+	private String name;
+	private Integer age;
+
+	public Person(String name, itn age) {
+		this.name = name;
+		this.age = age;
+	}
+}
+
+
+7. 연관 관계 주인
+- 데이터베이스에서 외래키를 가지는 엔티티
+- mappedBy로 연관 관계 주인을 지정(주인은 mappedBy 속성 사용X)
+
+8. 단방향 매핑
+- 연관 관계 주인에게만 연관 관계 주입
+- 보통 @ManytoOne 사용하게 되는 경우
+- e.g., mission-memberMissoin 관계에서 memberMission에 해당
+
+9. 양방향 매핑
+- 연관 관계 주인이 아닌 엔티티(1:N에서 1에 해당하는)에도 연관 관계 주입
+- mappedBy 사용하여 연관 관계 주인을 지정
+- cascade 설정 가능
+- 보통 @OnetoMany를 사용하게 되는 경우
+- e.g., mission-memberMission 관계에서 mission에 해당, mission이 삭제 or 변경되면 memberMission도 삭제 or 변경되어야 함(cascade)
+
+* 연관 관계 편의 메서드
+- player-team 관계에서 아래와 같이 값을 세팅해주는 것이 안전함
+player.setTeam(team)	// player -> team 연관관계 설정 @ManytoOne
+team.getPlayerList().add(player)	// team -> player 연관관계 설정 @OnetoMany
+- 위 코드를 player와 team 중 한 쪽에서 한 번에 설정해주는 것이 연관 관계 편의 메서드
+public void setTeam(Team team){
+	this.team = team;
+	team.getPlayerList().add(this);
+} 이거!!!
+
+
+10. 지연 로딩
+- @ManytoOne의 fetch 속성
+- fetch = FetchType.LAZY
+- N:1 관계에서 1에 해당하는 엔티티를 조회하는 시점을 해당 객체가 실제로 사용될 때로 늦추는 것
+- e.g., member-team 관계(N:1)에서 member와 team 객체가 같이 사용되는 경우가 거의 없는 경우
+- member를 조회하고 나중에 필요한 경우 team을 조회함
+- 프록시 사용
+- 프록시로 객체에 대한 참조(target)만 보관 -> 이 후 실제로 그 객체가 필요한 시점이 되면 그제서야 실제 데이터베이스에서 조회
+
+11. 영속성 컨텍스트
+- JPA에서 엔티티를 영구적으로 저장, 관리하고 다루는 환경
+- application과 데이터베이스 사이에서 객체를 보관하는 개념
+- EntituManager를 통해 영속성 컨텍스트에 접근
+- 1차 캐시
+- 동일성 보장
+- 트랜잭션을 지원하는 쓰기 지연
+- 변경 감지
+- 지연 로딩
+
+* 엔티티의 생명주기
+- 비영속
+영속성 컨텍스트와 전혀 관계가 없는 상태
+Member member = new Member();
+- 영속
+영속성 컨텍스트에 관리되는 상태
+Member member = new Member();
+EntityManager entityManager = entityManagerFacatory.createEntityManager();
+entityManager.persist(member);	// 1차 캐시에 저장됨 -> DB에 접근하는 것보다 속도 빠름?
+- 준영속
+영속성 컨텍스트에 저장되었다가 분리된 상태
+Member member = new Member();
+EntityManager entityManager = entityManagerFacatory.createEntityManager();
+entityManager.detach(member);
+- 삭제
+Member member = new Member();
+EntityManager entityManager = entityManagerFacatory.createEntityManager();
+entityManager.remove(member);
+
+=====???
+- findById 같은 것도 DB가 아니라 영속성컨텍스트에서 조회하는 것인지?
+
+
+12. N+1 문제
+- 하나의 쿼리문(1)의 결과로 N개의 쿼리가 더 발생하는 문제
+- e.g., Team, Member 엔티티가 있을 때, Team에 소속되어 있는 Member를 조회하는 경우
+Team 엔티티 안에 List<Member> members 필드가 있으니까 TeamRepository.findAll()로 쿼리 하나만 날려도 Member가 조회되겠지?
+--> 까보면 SELECT * from TEAM 쿼리에 추가적으로 SELECT * from Member WHERE Team={1~N} 쿼리 N개가 나감 == N+1문제
+- 원인: 처음에 Team을 TeamRepository.findAll()로 조회하면 Jpql이 동작함. 테이블이 아니라 엔티티 객체를 대상으로 쿼리를 날리는 것이기 때문에 JPA가 엔티티를 매핑한 과정을 떠올리면 왜 N개의 쿼리를 추가로 날렸는지 알 수 있음.
+--> team 엔티티를 매핑하고, 각 team_id에 해당하는 FK를 가진 member 엔티티를 매핑하여 가져옴
+
+====??
+JPA는 왜 join을 안 쓰는가!!!!!!!!!!!!!!!1??대체왜why
diff --git a/src/mission/chapter4/ERD.png b/src/mission/chapter4/ERD.png
index ba64132..d1e42e3 100644
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diff --git a/src/practice/chapter6/spring/.gitignore b/src/practice/chapter6/spring/.gitignore
deleted file mode 100644
index c2065bc..0000000
--- a/src/practice/chapter6/spring/.gitignore
+++ /dev/null
@@ -1,37 +0,0 @@
-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/
diff --git a/src/practice/chapter6/spring/build.gradle b/src/practice/chapter6/spring/build.gradle
deleted file mode 100644
index 8e94716..0000000
--- a/src/practice/chapter6/spring/build.gradle
+++ /dev/null
@@ -1,36 +0,0 @@
-plugins {
-	id 'java'
-	id 'org.springframework.boot' version '3.2.5'
-	id 'io.spring.dependency-management' version '1.1.4'
-}
-
-group = 'umc'
-version = '0.0.1-SNAPSHOT'
-
-java {
-	sourceCompatibility = '17'
-}
-
-configurations {
-	compileOnly {
-		extendsFrom annotationProcessor
-	}
-}
-
-repositories {
-	mavenCentral()
-}
-
-dependencies {
-//	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
-	implementation 'org.springframework.boot:spring-boot-starter-web'
-	compileOnly 'org.projectlombok:lombok'
-//	runtimeOnly 'com.mysql:mysql-connector-j'
-	annotationProcessor 'org.projectlombok:lombok'
-	testImplementation 'org.springframework.boot:spring-boot-starter-test'
-	testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
-}
-
-tasks.named('test') {
-	useJUnitPlatform()
-}
diff --git a/src/practice/chapter6/spring/gradle/wrapper/gradle-wrapper.jar b/src/practice/chapter6/spring/gradle/wrapper/gradle-wrapper.jar
deleted file mode 100644
index e644113..0000000
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diff --git a/src/practice/chapter6/spring/gradle/wrapper/gradle-wrapper.properties b/src/practice/chapter6/spring/gradle/wrapper/gradle-wrapper.properties
deleted file mode 100644
index b82aa23..0000000
--- a/src/practice/chapter6/spring/gradle/wrapper/gradle-wrapper.properties
+++ /dev/null
@@ -1,7 +0,0 @@
-distributionBase=GRADLE_USER_HOME
-distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
-networkTimeout=10000
-validateDistributionUrl=true
-zipStoreBase=GRADLE_USER_HOME
-zipStorePath=wrapper/dists
diff --git a/src/practice/chapter6/spring/gradlew b/src/practice/chapter6/spring/gradlew
deleted file mode 100644
index 1aa94a4..0000000
--- a/src/practice/chapter6/spring/gradlew
+++ /dev/null
@@ -1,249 +0,0 @@
-#!/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/HEAD/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
-
-# This is normally unused
-# shellcheck disable=SC2034
-APP_BASE_NAME=${0##*/}
-# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
-APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
-
-# Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD=maximum
-
-warn () {
-    echo "$*"
-} >&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: $JAVA_HOME
-
-Please set the JAVA_HOME variable in your environment to match the
-location of your Java installation."
-    fi
-else
-    JAVACMD=java
-    if ! command -v java >/dev/null 2>&1
-    then
-        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-
-Please set the JAVA_HOME variable in your environment to match the
-location of your Java installation."
-    fi
-fi
-
-# Increase the maximum file descriptors if we can.
-if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
-    case $MAX_FD in #(
-      max*)
-        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC2039,SC3045
-        MAX_FD=$( ulimit -H -n ) ||
-            warn "Could not query maximum file descriptor limit"
-    esac
-    case $MAX_FD in  #(
-      '' | soft) :;; #(
-      *)
-        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC2039,SC3045
-        ulimit -n "$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
-
-
-# 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"'
-
-# Collect all arguments for the java command:
-#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
-#     and any embedded shellness will be escaped.
-#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
-#     treated as '${Hostname}' itself on the command line.
-
-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 "$JAVACMD" "$@"
diff --git a/src/practice/chapter6/spring/gradlew.bat b/src/practice/chapter6/spring/gradlew.bat
deleted file mode 100644
index 25da30d..0000000
--- a/src/practice/chapter6/spring/gradlew.bat
+++ /dev/null
@@ -1,92 +0,0 @@
-@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=.
-@rem This is normally unused
-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. 1>&2
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
-echo. 1>&2
-echo Please set the JAVA_HOME variable in your environment to match the 1>&2
-echo location of your Java installation. 1>&2
-
-goto fail
-
-:findJavaFromJavaHome
-set JAVA_HOME=%JAVA_HOME:"=%
-set JAVA_EXE=%JAVA_HOME%/bin/java.exe
-
-if exist "%JAVA_EXE%" goto execute
-
-echo. 1>&2
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
-echo. 1>&2
-echo Please set the JAVA_HOME variable in your environment to match the 1>&2
-echo location of your Java installation. 1>&2
-
-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
diff --git a/src/practice/chapter6/spring/settings.gradle b/src/practice/chapter6/spring/settings.gradle
deleted file mode 100644
index ebf1ef8..0000000
--- a/src/practice/chapter6/spring/settings.gradle
+++ /dev/null
@@ -1 +0,0 @@
-rootProject.name = 'spring'
diff --git a/src/practice/chapter6/spring/src/main/java/umc/spring/Application.java b/src/practice/chapter6/spring/src/main/java/umc/spring/Application.java
deleted file mode 100644
index ff807df..0000000
--- a/src/practice/chapter6/spring/src/main/java/umc/spring/Application.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package umc.spring;
-
-import org.springframework.boot.SpringApplication;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
-
-@SpringBootApplication
-public class Application {
-
-	public static void main(String[] args) {
-		SpringApplication.run(Application.class, args);
-	}
-
-}
diff --git a/src/practice/chapter6/spring/src/main/resources/application.properties b/src/practice/chapter6/spring/src/main/resources/application.properties
deleted file mode 100644
index 0c7c661..0000000
--- a/src/practice/chapter6/spring/src/main/resources/application.properties
+++ /dev/null
@@ -1 +0,0 @@
-spring.application.name=spring
diff --git a/src/practice/chapter6/spring/src/test/java/umc/spring/ApplicationTests.java b/src/practice/chapter6/spring/src/test/java/umc/spring/ApplicationTests.java
deleted file mode 100644
index dc36e6c..0000000
--- a/src/practice/chapter6/spring/src/test/java/umc/spring/ApplicationTests.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package umc.spring;
-
-import org.junit.jupiter.api.Test;
-import org.springframework.boot.test.context.SpringBootTest;
-
-@SpringBootTest
-class ApplicationTests {
-
-	@Test
-	void contextLoads() {
-	}
-
-}