diff --git a/JavaOOP/lib/gson-2.8.6.jar b/JavaOOP/lib/gson-2.8.6.jar
deleted file mode 100644
index 4765c4af..00000000
Binary files a/JavaOOP/lib/gson-2.8.6.jar and /dev/null differ
diff --git a/JavaOOP/src/Java01.java b/JavaOOP/src/Java01.java
deleted file mode 100644
index eca7af38..00000000
--- a/JavaOOP/src/Java01.java
+++ /dev/null
@@ -1,6 +0,0 @@
-public class Java01 {
-
-    public static void main(String[] args) {
-        System.out.println("hello world");
-    }
-}
diff --git a/JavaOOP/src/Java02.java b/JavaOOP/src/Java02.java
deleted file mode 100644
index e0b26cf7..00000000
--- a/JavaOOP/src/Java02.java
+++ /dev/null
@@ -1,21 +0,0 @@
-import myObject.Book;
-
-public class Java02 {
-    public static void main(String[] args) {
-        // 프로그래밍 3대 요소 - 변수, 자료형, 할당
-        // {자료형} {변수} = {할당}
-        int a = 1, b = 1, c = a + b;
-        System.out.println(c);
-
-        float f = 34.5f;
-        System.out.println(f);
-
-        char d = 'A';
-        System.out.println(d);
-
-        boolean g = true;
-        System.out.println(g);
-
-        Book book;
-    }
-}
diff --git a/JavaOOP/src/Java03.java b/JavaOOP/src/Java03.java
deleted file mode 100644
index e648b660..00000000
--- a/JavaOOP/src/Java03.java
+++ /dev/null
@@ -1,35 +0,0 @@
-import myObject.Book;
-import myObject.Person;
-
-public class Java03 {
-
-    public static void main(String[] args) {
-        // 관계를 이해하라. PDT vs UDDT
-
-        // 정수 1개를 저장하기 위한 변수를 선언하시오.
-        int a = 10;
-
-        // 책 1권을 저장하기 위한 선언하시오.
-        Book b = new Book();
-        b.title = "자바";
-        b.price = 15000;
-        b.company = "한빛미디어";
-        b.page = 700;
-
-        System.out.println(b.title);
-        System.out.println(b.price);
-        System.out.println(b.company);
-        System.out.println(b.page);
-
-        Person p = new Person();
-        p.name = "홍길동";
-        p.age = 20;
-        p.weight = 78.9f;
-        p.height = 184.8f;
-
-        System.out.println(p.name);
-        System.out.println(p.age);
-        System.out.println(p.weight);
-        System.out.println(p.height);
-    }
-}
diff --git a/JavaOOP/src/Java04.java b/JavaOOP/src/Java04.java
deleted file mode 100644
index e1b2d6ff..00000000
--- a/JavaOOP/src/Java04.java
+++ /dev/null
@@ -1,32 +0,0 @@
-public class Java04 {
-
-    public static void main(String[] args) {
-        // 변수 VS 배열
-        int a = 10, b = 20, c = 30;
-
-        // a + b + c = ?  메소드 처리 -> hap()
-        hap(a, b, c);
-
-        int[] arr = new int[3];
-        arr[0] = 10;
-        arr[1] = 20;
-        arr[2] = 30;
-
-        hap(arr);
-    }
-
-    // 하나의 값마다 파라미터로 받아야함 -> 데이터 이동이 불편
-    public static void hap(int a, int b, int c) {
-        int sum = a + b + c;
-        System.out.println(sum);
-    }
-
-    // 여러 값을 배열로 한번에 이동
-    public static void hap(int[] arr) {
-        int sum = 0;
-        for (int i : arr) {
-            sum += i;
-        }
-        System.out.println(sum);
-    }
-}
diff --git a/JavaOOP/src/Java05.java b/JavaOOP/src/Java05.java
deleted file mode 100644
index eb8a3ee1..00000000
--- a/JavaOOP/src/Java05.java
+++ /dev/null
@@ -1,40 +0,0 @@
-public class Java05 {
-    public static void main(String[] args) {
-        // 2차원 배열
-        int[][] a = new int[3][3];
-        a[0][0] = 1;
-        a[0][1] = 2;
-        a[0][2] = 3;
-
-        a[1][0] = 1;
-        a[1][1] = 2;
-        a[1][2] = 3;
-
-        a[2][0] = 1;
-        a[2][1] = 2;
-        a[2][2] = 3;
-
-        for (int i = 0; i < a.length ; i++) {
-            for (int j = 0; j < a[i].length; j++) {
-                System.out.print(a[i][j] + "\t");
-            }
-            System.out.println();
-        }
-
-        // 가변길이 배열
-        int[][] star = new int[5][];
-        star[0] = new int[1];
-        star[1] = new int[2];
-        star[2] = new int[3];
-        star[3] = new int[4];
-        star[4] = new int[5];
-
-        for (int i = 0; i <star.length ; i++) {
-            for (int j = 0; j < star[i].length ; j++) {
-                star[i][j] = '*';
-                System.out.print((char) star[i][j]);
-            }
-            System.out.println();
-        }
-    }
-}
diff --git a/JavaOOP/src/Java06.java b/JavaOOP/src/Java06.java
deleted file mode 100644
index acc426cb..00000000
--- a/JavaOOP/src/Java06.java
+++ /dev/null
@@ -1,33 +0,0 @@
-public class Java06 {
-    public static void main(String[] args) {
-        // 메소드 -> 동작(method), 기능(function)
-        int a = 67;
-        int b = 98;
-
-        int result = sum(a, b);
-        System.out.println(result);
-
-        int[] arr = makeArr();
-        int hap = 0;
-        for (int i = 0; i < arr.length; i++) {
-            hap += arr[i];
-        }
-        System.out.println(hap);
-    }
-
-    // 정수 2개를 매개변수로 받아서 합을 리턴하는 메소드를 정의하시오.
-    // static 메소드에서는 static 메소드만 호출 가능
-    public static int sum(int a, int b) {
-        return a + b;
-    }
-
-    // 값은 하나만 리턴이 가능하다.
-    // 여러 값을 리턴 받고 싶다면? -> 배열
-    public static int[] makeArr() {
-        int[] arr = new int[3];
-        arr[0] = 10;
-        arr[1] = 20;
-        arr[2] = 30;
-        return arr;
-    }
-}
diff --git a/JavaOOP/src/Java07.java b/JavaOOP/src/Java07.java
deleted file mode 100644
index 698704e2..00000000
--- a/JavaOOP/src/Java07.java
+++ /dev/null
@@ -1,29 +0,0 @@
-public class Java07 {
-    public static void main(String[] args) {
-
-        int a = 20;
-        float b = 56.7f;
-
-        // call by value
-        float v = sum(a, b);
-        System.out.println(v);
-
-        int[] arr = {1, 2, 3, 4, 5};
-
-        // call by reference
-        int vv = arrSum(arr);
-        System.out.println(vv);
-    }
-
-    public static float sum(int a, float b) {
-        return a + b;
-    }
-
-    public static int arrSum(int[] arr) {
-        int sum = 0;
-        for (int i : arr) {
-            sum += i;
-        }
-        return sum;
-    }
-}
diff --git a/JavaOOP/src/Java08.java b/JavaOOP/src/Java08.java
deleted file mode 100644
index 0641b306..00000000
--- a/JavaOOP/src/Java08.java
+++ /dev/null
@@ -1,13 +0,0 @@
-public class Java08 {
-    public static void main(String[] args) {
-        int a = 30;
-        int b = 50;
-        int v = add(a, b); // static method call
-        System.out.println(v);
-    }
-
-    public static int add(int a, int b) {
-        int sum = a + b;
-        return sum;
-    }
-}
diff --git a/JavaOOP/src/Java09.java b/JavaOOP/src/Java09.java
deleted file mode 100644
index eb2c3cde..00000000
--- a/JavaOOP/src/Java09.java
+++ /dev/null
@@ -1,15 +0,0 @@
-public class Java09 {
-    public static void main(String[] args) {
-        int a = 56;
-        int b = 40;
-
-        Java09 java09 = new Java09(); // heap area 에 객체 생성
-        int v = java09.add(a, b);
-        System.out.println(v);
-    }
-
-    public int add(int a, int b) {
-        int sum = a + b;
-        return sum;
-    }
-}
diff --git a/JavaOOP/src/Java10.java b/JavaOOP/src/Java10.java
deleted file mode 100644
index 98e99ce9..00000000
--- a/JavaOOP/src/Java10.java
+++ /dev/null
@@ -1,23 +0,0 @@
-import myObject.BookVO;
-
-public class Java10 {
-    public static void main(String[] args) {
-
-        /**
-         * 책 (BookVO) 이라는 자료형 만들기 -> class 를 통해 만든다.
-         * class 를 만들면 디폴트 생성자가 자동 생성된다. (생략)
-         * 생성자는 객체를 생성하는 작업을 한다. (기계어코드)
-         * 객체를 생성하면 이 객체를 가리키는 this 객체도 자동 생성된다.
-         */
-        BookVO b = new BookVO(); // 객체 생성
-        b.title = "자바";
-        b.price = 20000;
-        b.company = "출판사";
-        b.page = 670;
-
-        System.out.println(b.title);
-        System.out.println(b.price);
-        System.out.println(b.company);
-        System.out.println(b.page);
-    }
-}
diff --git a/JavaOOP/src/Java11.java b/JavaOOP/src/Java11.java
deleted file mode 100644
index 63ab6ca6..00000000
--- a/JavaOOP/src/Java11.java
+++ /dev/null
@@ -1,14 +0,0 @@
-import myObject.BookVO;
-
-public class Java11 {
-
-    public static void main(String[] args) {
-        // 생성자 -> 생성 + 초기화 -> 중복정의
-        BookVO b = new BookVO("자바",20000,"길벗",790);
-
-        System.out.println(b.title);
-        System.out.println(b.price);
-        System.out.println(b.company);
-        System.out.println(b.page);
-    }
-}
diff --git a/JavaOOP/src/Java12.java b/JavaOOP/src/Java12.java
deleted file mode 100644
index b1f916f1..00000000
--- a/JavaOOP/src/Java12.java
+++ /dev/null
@@ -1,16 +0,0 @@
-import myObject.PrivateConstructor;
-
-public class Java12 {
-
-    public static void main(String[] args) {
-
-//        // 생성자가 private 이므로 객체 생성 불가
-//        PrivateConstructor pc = new PrivateConstructor();
-//
-//        // non-static-method 사용 불가
-//        PrivateConstructor.nonStaticMethod();
-
-        // static-method 만 사용가능
-        PrivateConstructor.staticMethod();
-    }
-}
diff --git a/JavaOOP/src/Java13.java b/JavaOOP/src/Java13.java
deleted file mode 100644
index e67c24bc..00000000
--- a/JavaOOP/src/Java13.java
+++ /dev/null
@@ -1,25 +0,0 @@
-import myObject.BookDTO;
-
-public class Java13 {
-    public static void main(String[] args) {
-        // 책 -> class(BookDTO) -> 객체 -> 인스턴스
-        String title = "자바";
-        int price = 25000;
-        String company = "출판사";
-        int page = 890;
-
-        // 데이터 이동을 쉽게 하기 위한 DTO
-        BookDTO dto; // dto (Object : 객체)
-        dto = new BookDTO(title, price, company, page); // dto (Instance : 인스턴스)
-
-        // 데이터 이동
-        bookPrint(dto);
-    }
-
-    public static void bookPrint(BookDTO dto) {
-        System.out.println(dto.title);
-        System.out.println(dto.price);
-        System.out.println(dto.company);
-        System.out.println(dto.page);
-    }
-}
diff --git a/JavaOOP/src/Java14.java b/JavaOOP/src/Java14.java
deleted file mode 100644
index f9fff8ab..00000000
--- a/JavaOOP/src/Java14.java
+++ /dev/null
@@ -1,19 +0,0 @@
-import myObject.MemberVO;
-
-public class Java14 {
-
-    public static void main(String[] args) {
-
-        MemberVO m = new MemberVO();
-
-        m.setName("홍길동");
-        m.setAge(20);
-        m.setTel("010-1234-1234");
-        m.setAddr("서울");
-
-        System.out.println(m.getName());
-        System.out.println(m.getAge());
-        System.out.println(m.getTel());
-        System.out.println(m.getAddr());
-    }
-}
diff --git a/JavaOOP/src/Java15.java b/JavaOOP/src/Java15.java
deleted file mode 100644
index 634cea06..00000000
--- a/JavaOOP/src/Java15.java
+++ /dev/null
@@ -1,11 +0,0 @@
-import myObject.MemberVO;
-
-public class Java15 {
-    public static void main(String[] args) {
-
-        MemberVO m = new MemberVO("홍길동", 20, "010-1123-1123", "서울");
-
-        System.out.println(m.toString());
-        System.out.println(m); // toString 생략 가능
-    }
-}
diff --git a/JavaOOP/src/Java16.java b/JavaOOP/src/Java16.java
deleted file mode 100644
index c190c18b..00000000
--- a/JavaOOP/src/Java16.java
+++ /dev/null
@@ -1,12 +0,0 @@
-import myObject.OverLoad;
-
-public class Java16 {
-    public static void main(String[] args) {
-
-        OverLoad ov = new OverLoad();
-
-        ov.hap(20, 50); // hap_int_int(20, 50)
-        ov.hap(23.4f, 56); // hap_float_int(23.4f, 56)
-        ov.hap(56.7f, 78.9f); // hap_float_float(56.7f, 78.9f)
-    }
-}
diff --git a/JavaOOP/src/Java17.java b/JavaOOP/src/Java17.java
deleted file mode 100644
index 23d7346d..00000000
--- a/JavaOOP/src/Java17.java
+++ /dev/null
@@ -1,28 +0,0 @@
-import com.google.gson.Gson;
-import myObject.BookVO;
-import myObject.MyUtil;
-
-public class Java17 {
-    public static void main(String[] args) {
-
-        // 1. Java 에서 제공해주는 class 들 -> API
-        String str = new String("apple");
-        // new String 생략 가능
-        String str1 = "apple";
-        System.out.println(str1.toUpperCase()); // 소문자 -> 대문자 변환 메소드
-
-        // 2. 직접 만들어서 사용하는 class 들 -> DTO/VO, DAO, Utility ... API
-        MyUtil my = new MyUtil();
-        int sum1to10 = my.hap();
-        System.out.println(sum1to10);
-
-        // 3. 다른 회사(사람) 에서 만들어 놓은 class
-        // Gson 사용해보기 : object -> json 형태로 바꿔주는 API
-        Gson g = new Gson();
-        BookVO vo = new BookVO("자바", 13000, "출판사", 800);
-        String json = g.toJson(vo);
-
-        System.out.println(json);
-    }
-}
-
diff --git a/JavaOOP/src/Java18.java b/JavaOOP/src/Java18.java
deleted file mode 100644
index beb47b20..00000000
--- a/JavaOOP/src/Java18.java
+++ /dev/null
@@ -1,17 +0,0 @@
-import myObject.Animal;
-import myObject.Cat;
-import myObject.Dog;
-
-public class Java18 {
-    public static void main(String[] args) {
-
-//        Dog dog = new Dog();
-//        Cat cat = new Cat();
-
-        Animal dog = new Dog();
-        Animal cat = new Cat();
-
-        dog.eat();
-        cat.eat();
-    }
-}
diff --git a/JavaOOP/src/Java19.java b/JavaOOP/src/Java19.java
deleted file mode 100644
index d0c9db5e..00000000
--- a/JavaOOP/src/Java19.java
+++ /dev/null
@@ -1,13 +0,0 @@
-import myObject.Animal;
-import myObject.Cat;
-import myObject.Dog;
-
-public class Java19 {
-    public static void main(String[] args) {
-        Animal dog = new Dog(); // 상속 관계 : 자동 형변환 -> Object casting  부모 클래스 = 자식클래스 (Up casting)
-        Animal cat = new Cat();
-
-        dog.eat();
-        cat.eat();
-    }
-}
diff --git a/JavaOOP/src/Java20.java b/JavaOOP/src/Java20.java
deleted file mode 100644
index fec55465..00000000
--- a/JavaOOP/src/Java20.java
+++ /dev/null
@@ -1,23 +0,0 @@
-import myObject.Animal;
-import myObject.Cat;
-import myObject.Dog;
-
-public class Java20 {
-    public static void main(String[] args) {
-
-        // upcasting
-        Animal cat = new Cat();
-        Animal dog = new Dog();
-
-        // 오버라이딩 한 메소드 사용
-        // cat 에만 있는 메소드는 사용 하지못함 -> cat.say() X
-        cat.eat(); // 컴파일 시점 -> Animal 의 eat(), 실행 시점 -> Cat 의 eat()
-        dog.eat(); // 컴파일 시점 -> Animal 의 eat(), 실행 시점 -> Dog 의 eat()
-
-
-        // downcasting
-        // Cat c = (Cat) ani;
-        // c.night();
-        ((Cat) cat).say(); // . 연산자가 casting 연산자 보다 우선순위가 높다.
-    }
-}
diff --git a/JavaOOP/src/Java21.java b/JavaOOP/src/Java21.java
deleted file mode 100644
index 6bd158cb..00000000
--- a/JavaOOP/src/Java21.java
+++ /dev/null
@@ -1,22 +0,0 @@
-import myObject.Animal;
-import myObject.Cat;
-import myObject.Dog;
-
-public class Java21 {
-    public static void main(String[] args) {
-        // 1. 다형성 인수
-        Dog dog = new Dog();
-        Cat cat = new Cat();
-
-        display(dog);
-        display(cat);
-    }
-
-    public static void display(Animal animal) { // 다형성 인수 upcasting
-        animal.eat();
-        // Cat 타입 인지 확인 instanceof -> Cat 타입 일때만 실행
-        if (animal instanceof Cat) {
-            ((Cat) animal).say(); // downcasting
-        }
-    }
-}
diff --git a/JavaOOP/src/Java22.java b/JavaOOP/src/Java22.java
deleted file mode 100644
index 1003571f..00000000
--- a/JavaOOP/src/Java22.java
+++ /dev/null
@@ -1,19 +0,0 @@
-import myObject.Animal;
-import myObject.Cat;
-import myObject.Dog;
-
-public class Java22 {
-    public static void main(String[] args) {
-        // 2. 다형성 배열
-        Animal[] animals = new Animal[2];
-        animals[0] = new Dog();
-        animals[1] = new Cat();
-
-        for (Animal animal : animals) {
-            animal.eat();
-            if (animal instanceof Cat) {
-                ((Cat) animal).say();
-            }
-        }
-    }
-}
diff --git a/JavaOOP/src/Java23.java b/JavaOOP/src/Java23.java
deleted file mode 100644
index ee72704c..00000000
--- a/JavaOOP/src/Java23.java
+++ /dev/null
@@ -1,19 +0,0 @@
-import poly.Animal;
-import poly.Cat;
-import poly.Dog;
-
-public class Java23 {
-    public static void main(String[] args) {
-        // 추상클래스
-        // Animal animal = new Animal; (X)
-        // upcasting 으로 활용
-        Animal cat = new Cat();
-        Animal dog = new Dog();
-
-        cat.eat();
-        cat.move();
-
-        dog.eat();
-        dog.move();
-    }
-}
diff --git a/JavaOOP/src/Java24.java b/JavaOOP/src/Java24.java
deleted file mode 100644
index 3d6cdfa6..00000000
--- a/JavaOOP/src/Java24.java
+++ /dev/null
@@ -1,20 +0,0 @@
-import poly.Radio;
-import poly.RemoCon;
-import poly.TV;
-
-public class Java24 {
-    public static void main(String[] args) {
-        // 인터페이스
-        // 객체 생성 X : RemoCon r = new RemoCon(); (X)
-
-        RemoCon r = new TV();
-        r.chUp();
-        r.chDown();
-        r.internet();
-
-        r = new Radio();
-        r.chUp();
-        r.chDown();
-        r.internet();
-    }
-}
diff --git a/JavaOOP/src/Java25.java b/JavaOOP/src/Java25.java
deleted file mode 100644
index 84f6b686..00000000
--- a/JavaOOP/src/Java25.java
+++ /dev/null
@@ -1,16 +0,0 @@
-import poly.Radio;
-import poly.RemoCon;
-import poly.TV;
-
-public class Java25 {
-    public static void main(String[] args) {
-        RemoCon r = new TV();
-        for (int i = 0; i < 10; i++) {
-            r.chUp();
-        }
-        for (int i = 0; i < 10; i++) {
-            r.chDown();
-        }
-        r.internet();
-    }
-}
diff --git a/JavaOOP/src/Java26.java b/JavaOOP/src/Java26.java
deleted file mode 100644
index aa4760f5..00000000
--- a/JavaOOP/src/Java26.java
+++ /dev/null
@@ -1,15 +0,0 @@
-import myObject.DBConnect;
-import myObject.JavaMySQLDriver;
-import myObject.JavaOracleDriver;
-
-public class Java26 {
-    public static void main(String[] args) {
-
-        // Oracle, MySQL 등을 사용하기 위해 Driver class 가 필요
-        DBConnect conn = new JavaOracleDriver();
-        conn.getConnection("url", "id", "password");
-
-        conn = new JavaMySQLDriver();
-        conn.getConnection("url", "id", "password");
-    }
-}
diff --git a/JavaOOP/src/Java27.java b/JavaOOP/src/Java27.java
deleted file mode 100644
index 8294368d..00000000
--- a/JavaOOP/src/Java27.java
+++ /dev/null
@@ -1,10 +0,0 @@
-import poly.A;
-
-public class Java27 {
-    public static void main(String[] args) {
-
-        Object o = new A();
-        ((A) o).display();
-        System.out.println(o.toString());
-    }
-}
diff --git a/JavaOOP/src/Java28.java b/JavaOOP/src/Java28.java
deleted file mode 100644
index daa08c3d..00000000
--- a/JavaOOP/src/Java28.java
+++ /dev/null
@@ -1,20 +0,0 @@
-import myObject.A;
-import myObject.B;
-
-public class Java28 {
-    public static void main(String[] args) {
-        A a = new A();
-        display(a);
-
-        B b = new B();
-        display(b);
-    }
-
-    private static void display(Object o) {
-        if (o instanceof A) {
-            ((A) o).go();
-        } else {
-            ((B) o).go();
-        }
-    }
-}
diff --git a/JavaOOP/src/Java29.java b/JavaOOP/src/Java29.java
deleted file mode 100644
index 7990f13b..00000000
--- a/JavaOOP/src/Java29.java
+++ /dev/null
@@ -1,31 +0,0 @@
-import myObject.A;
-import myObject.B;
-
-public class Java29 {
-    public static void main(String[] args) {
-        // A, B 클래스를 저장할 배열
-        Object[] o = new Object[2];
-        o[0] = new A();
-        o[1] = new B();
-
-        for (int i = 0; i < o.length; i++) {
-            if (o[i] instanceof A) {
-                ((A) o[i]).go();
-            } else {
-                ((B) o[i]).go();
-            }
-        }
-
-        printGo(o);
-    }
-
-    private static void printGo(Object[] o) {
-        for (int i = 0; i < o.length; i++) {
-            if (o[i] instanceof A) {
-                ((A) o[i]).go();
-            } else {
-                ((B) o[i]).go();
-            }
-        }
-    }
-}
diff --git a/JavaOOP/src/Java30.java b/JavaOOP/src/Java30.java
deleted file mode 100644
index f04e2169..00000000
--- a/JavaOOP/src/Java30.java
+++ /dev/null
@@ -1,9 +0,0 @@
-import kr.study.MyClass;
-
-public class Java30 {
-    public static void main(String[] args) {
-        MyClass myClass = new MyClass();
-        int sum = myClass.sum(3, 4);
-        System.out.println(sum);
-    }
-}
diff --git a/JavaOOP/src/Java31.java b/JavaOOP/src/Java31.java
deleted file mode 100644
index 1d3190a3..00000000
--- a/JavaOOP/src/Java31.java
+++ /dev/null
@@ -1,13 +0,0 @@
-public class Java31 {
-    public static void main(String[] args) {
-        String str = "apple"; // java.lang.String str = new java.lang.String("apple");
-
-        // String 클래스의 다양한 메소드들
-        System.out.println(str.toUpperCase());
-        System.out.println(str.charAt(3));
-        System.out.println(str.length());
-        System.out.println(str.indexOf("pl"));
-        System.out.println(str.indexOf("px"));
-        System.out.println(str.replaceAll("p", "x"));
-    }
-}
diff --git a/JavaOOP/src/Java32.java b/JavaOOP/src/Java32.java
deleted file mode 100644
index aedd1246..00000000
--- a/JavaOOP/src/Java32.java
+++ /dev/null
@@ -1,21 +0,0 @@
-public class Java32 {
-    public static void main(String[] args) {
-
-        // new 로 생성
-        String str1 = new String("APPLE");
-        String str2 = new String("APPLE");
-
-        // str1과 str2는 객체 이므로 heap 영역에 저장된 번지수가 저장됨
-        // new 로 생성하면 각각 다른 객체를 생성하여 가리키므로 다름
-        System.out.println(str1 == str2);
-
-        // 번지수가 아닌 값을 비교 하려면 equals 사용
-        System.out.println(str1.equals(str2));
-
-        // 문자열 상수로 생성
-        String str3 = "APPLE";
-        String str4 = "APPLE";
-
-        System.out.println(str3 == str4);
-    }
-}
diff --git a/JavaOOP/src/Java33.java b/JavaOOP/src/Java33.java
deleted file mode 100644
index ba5a3088..00000000
--- a/JavaOOP/src/Java33.java
+++ /dev/null
@@ -1,19 +0,0 @@
-import kr.study.IntArray;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class Java33 {
-    public static void main(String[] args) {
-
-        IntArray arr = new IntArray(5);
-
-        arr.add(10);
-        arr.add(20);
-        arr.add(30);
-
-        for (int i = 0; i < arr.size(); i++) {
-            System.out.println(arr.get(i));
-        }
-    }
-}
diff --git a/JavaOOP/src/Java34.java b/JavaOOP/src/Java34.java
deleted file mode 100644
index d2a43bf5..00000000
--- a/JavaOOP/src/Java34.java
+++ /dev/null
@@ -1,64 +0,0 @@
-public class Java34 {
-    public static void main(String[] args) {
-
-        int a = 1; // 기본자료형
-        Integer b = new Integer(1); // 객체자료형
-
-        System.out.println(a);
-        System.out.println(b.intValue()); // 1
-        System.out.println(b.toString()); // "1"
-
-        System.out.println("=======================");
-
-        int c = new Integer(1); // unboxing
-        Integer d = 1; // boxing
-
-        System.out.println(c);
-        System.out.println(d.intValue()); // 1
-        System.out.println(d.toString()); // "1"
-
-        System.out.println("=======================");
-
-        Object[] obj = new Object[3];
-        obj[0] = new Integer(1);
-        obj[1] = new Integer(2);
-        obj[2] = new Integer(3);
-
-        System.out.println(obj[0].toString());
-        System.out.println(obj[1].toString());
-        System.out.println(obj[2].toString());
-
-        System.out.println("=======================");
-
-        Object[] obj2 = new Object[3];
-        obj2[0] = 1;
-        obj2[1] = 2;
-        obj2[2] = 3;
-
-        System.out.println(obj2[0].toString());
-        System.out.println(obj2[1].toString());
-        System.out.println(obj2[2].toString());
-
-        System.out.println("=======================");
-
-        // "100" + "100" = 200
-        String x = "100";
-        String y = "100";
-        System.out.println(x + y); // "100100"
-
-        System.out.println("=======================");
-
-        int i = Integer.parseInt(x);
-        int j = Integer.parseInt(y);
-
-        System.out.println(i + j); // 200
-
-        System.out.println("=======================");
-
-        // 100 + 100 = "100100"
-        String v1 = String.valueOf(i);
-        String v2 = String.valueOf(j);
-
-        System.out.println(v1 + v2);
-    }
-}
diff --git a/JavaOOP/src/kr/study/IntArray.java b/JavaOOP/src/kr/study/IntArray.java
deleted file mode 100644
index ce69c88a..00000000
--- a/JavaOOP/src/kr/study/IntArray.java
+++ /dev/null
@@ -1,29 +0,0 @@
-package kr.study;
-
-public class IntArray {
-    private int count; // 배열의 현재 인덱스
-    private int[] arr; // 배열 생성
-
-    // 생성자
-    public IntArray(){
-        this(10); // 입력값이 없으면 길이 10
-    }
-    public IntArray(int init){
-        arr=new int[init]; // 입력한 값의 길이를 생성
-    }
-
-    // 배열에 데이터 추가
-    public void add(int data){
-        arr[count++]=data;
-    }
-
-    // 배열의 값 반환
-    public int get(int index){
-        return arr[index];
-    }
-
-    // 배열의 길이 출력
-    public int size(){
-        return count;
-    }
-}
diff --git a/JavaOOP/src/kr/study/MyClass.java b/JavaOOP/src/kr/study/MyClass.java
deleted file mode 100644
index 5ec39410..00000000
--- a/JavaOOP/src/kr/study/MyClass.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package kr.study;
-
-public class MyClass { // 패키지가 있을 경우 public 을 생략하면 default 접근권한을 가진다.
-    public int sum(int a, int b){
-        int hap=0;
-        for(int i=a;i<=b;i++){
-            hap+=i;
-        }
-        return hap;
-    }
-}
diff --git a/JavaOOP/src/myObject/A.java b/JavaOOP/src/myObject/A.java
deleted file mode 100644
index daa55c0b..00000000
--- a/JavaOOP/src/myObject/A.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package myObject;
-
-public class A {
-    public void go() {
-        System.out.println("A의 go 메소드");
-    }
-}
diff --git a/JavaOOP/src/myObject/Animal.java b/JavaOOP/src/myObject/Animal.java
deleted file mode 100644
index fd0c430d..00000000
--- a/JavaOOP/src/myObject/Animal.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package myObject;
-
-public class Animal {
-    public void eat() {
-        System.out.println("냠냠");
-    }
-}
diff --git a/JavaOOP/src/myObject/B.java b/JavaOOP/src/myObject/B.java
deleted file mode 100644
index ce0710d3..00000000
--- a/JavaOOP/src/myObject/B.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package myObject;
-
-public class B {
-    public void go() {
-        System.out.println("B의 go 메소드");
-    }
-}
diff --git a/JavaOOP/src/myObject/Book.java b/JavaOOP/src/myObject/Book.java
deleted file mode 100644
index d4964d33..00000000
--- a/JavaOOP/src/myObject/Book.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package myObject;
-
-public class Book {
-    public String title;
-    public int price;
-    public String company;
-    public int page;
-}
diff --git a/JavaOOP/src/myObject/BookDTO.java b/JavaOOP/src/myObject/BookDTO.java
deleted file mode 100644
index 14704329..00000000
--- a/JavaOOP/src/myObject/BookDTO.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package myObject;
-
-public class BookDTO {
-    public String title;
-    public int price;
-    public String company;
-    public int page;
-
-    public BookDTO() {
-    }
-
-    public BookDTO(String title, int price, String company, int page) {
-        this.title = title;
-        this.price = price;
-        this.company = company;
-        this.page = page;
-    }
-}
diff --git a/JavaOOP/src/myObject/BookVO.java b/JavaOOP/src/myObject/BookVO.java
deleted file mode 100644
index 1916da5c..00000000
--- a/JavaOOP/src/myObject/BookVO.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package myObject;
-
-public class BookVO {
-    public String title;
-    public int price;
-    public String company;
-    public int page;
-
-    public BookVO() {
-    }
-
-    public BookVO(String title, int price, String company, int page) {
-        this.title = title;
-        this.price = price;
-        this.company = company;
-        this.page = page;
-    }
-}
diff --git a/JavaOOP/src/myObject/Cat.java b/JavaOOP/src/myObject/Cat.java
deleted file mode 100644
index c63154fd..00000000
--- a/JavaOOP/src/myObject/Cat.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package myObject;
-
-public class Cat extends Animal{
-    @Override
-    public void eat() {
-        System.out.println("고양이가 먹는다");
-    }
-
-    public void say() {
-        System.out.println("냐옹옹");
-    }
-}
diff --git a/JavaOOP/src/myObject/DBConnect.java b/JavaOOP/src/myObject/DBConnect.java
deleted file mode 100644
index 3465004b..00000000
--- a/JavaOOP/src/myObject/DBConnect.java
+++ /dev/null
@@ -1,6 +0,0 @@
-package myObject;
-
-public interface DBConnect {
-    // 규약
-    void getConnection(String url, String user, String password);
-}
diff --git a/JavaOOP/src/myObject/Dog.java b/JavaOOP/src/myObject/Dog.java
deleted file mode 100644
index 97f6ea9d..00000000
--- a/JavaOOP/src/myObject/Dog.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package myObject;
-
-public class Dog extends Animal{
-    @Override
-    public void eat() {
-        System.out.println("개가 먹는다");
-    }
-}
diff --git a/JavaOOP/src/myObject/JavaMySQLDriver.java b/JavaOOP/src/myObject/JavaMySQLDriver.java
deleted file mode 100644
index beb723a9..00000000
--- a/JavaOOP/src/myObject/JavaMySQLDriver.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package myObject;
-
-public class JavaMySQLDriver implements DBConnect{
-    @Override
-    public void getConnection(String url, String user, String password) {
-        System.out.println("MySQL DB에 접속합니다.");
-    }
-}
diff --git a/JavaOOP/src/myObject/JavaOracleDriver.java b/JavaOOP/src/myObject/JavaOracleDriver.java
deleted file mode 100644
index fded2638..00000000
--- a/JavaOOP/src/myObject/JavaOracleDriver.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package myObject;
-
-public class JavaOracleDriver implements DBConnect{
-    @Override
-    public void getConnection(String url, String user, String password) {
-        System.out.println("Oracle DB에 접속합니다.");
-    }
-}
diff --git a/JavaOOP/src/myObject/MemberVO.java b/JavaOOP/src/myObject/MemberVO.java
deleted file mode 100644
index 3676d8d2..00000000
--- a/JavaOOP/src/myObject/MemberVO.java
+++ /dev/null
@@ -1,59 +0,0 @@
-package myObject;
-
-public class MemberVO {
-    private String name;
-    private int age;
-    private String tel;
-    private String addr ;
-
-    public MemberVO(){}
-
-    public MemberVO(String name, int age, String tel, String addr) {
-        this.name = name;
-        this.age = age;
-        this.tel = tel;
-        this.addr = addr;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    public int getAge() {
-        return age;
-    }
-
-    public void setAge(int age) {
-        this.age = age;
-    }
-
-    public String getTel() {
-        return tel;
-    }
-
-    public void setTel(String tel) {
-        this.tel = tel;
-    }
-
-    public String getAddr() {
-        return addr;
-    }
-
-    public void setAddr(String addr) {
-        this.addr = addr;
-    }
-
-    @Override
-    public String toString() {
-        return "MemberVO{" +
-                "name='" + name + '\'' +
-                ", age=" + age +
-                ", tel='" + tel + '\'' +
-                ", addr='" + addr + '\'' +
-                '}';
-    }
-}
\ No newline at end of file
diff --git a/JavaOOP/src/myObject/MyUtil.java b/JavaOOP/src/myObject/MyUtil.java
deleted file mode 100644
index ea906040..00000000
--- a/JavaOOP/src/myObject/MyUtil.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package myObject;
-
-public class MyUtil {
-    public int hap() {
-        int sum = 0;
-        for (int i = 1; i <= 10; i++) {
-            sum += i;
-        }
-        return sum;
-    }
-}
diff --git a/JavaOOP/src/myObject/OverLoad.java b/JavaOOP/src/myObject/OverLoad.java
deleted file mode 100644
index 55100472..00000000
--- a/JavaOOP/src/myObject/OverLoad.java
+++ /dev/null
@@ -1,14 +0,0 @@
-package myObject;
-
-public class OverLoad {
-    // 동작(method)으로만 이루어진 객체
-    public void hap(int a, int b){
-        System.out.println(a+b);
-    }
-    public void hap(float a, int b){
-        System.out.println(a+b);
-    }
-    public void hap(float a, float b){
-        System.out.println(a+b);
-    }
-}
diff --git a/JavaOOP/src/myObject/Person.java b/JavaOOP/src/myObject/Person.java
deleted file mode 100644
index 8e41a089..00000000
--- a/JavaOOP/src/myObject/Person.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package myObject;
-
-public class Person {
-    public String name;
-    public int age;
-    public float weight;
-    public float height;
-}
diff --git a/JavaOOP/src/myObject/PrivateConstructor.java b/JavaOOP/src/myObject/PrivateConstructor.java
deleted file mode 100644
index 4ae43267..00000000
--- a/JavaOOP/src/myObject/PrivateConstructor.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package myObject;
-
-public class PrivateConstructor {
-
-    private PrivateConstructor() {
-    }
-
-    public void nonStaticMethod() {
-        System.out.println("non-static-method");
-    }
-
-    public static void staticMethod() {
-        System.out.println("static method");
-    }
-}
diff --git a/JavaOOP/src/poly/A.java b/JavaOOP/src/poly/A.java
deleted file mode 100644
index dc2c943c..00000000
--- a/JavaOOP/src/poly/A.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package poly;
-
-public class A{
-
-    public void display() {
-        System.out.println("A 클래스");
-    }
-
-    @Override
-    public String toString() {
-        return "재정의 메소드";
-    }
-}
diff --git a/JavaOOP/src/poly/Animal.java b/JavaOOP/src/poly/Animal.java
deleted file mode 100644
index 5b6017ed..00000000
--- a/JavaOOP/src/poly/Animal.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package poly;
-
-// 추상 클래스 -> 불완전 클래스 : 객체 생성 불가  new Animal() (X)
-public abstract class Animal {
-
-    public abstract void eat(); // 추상 메소드 -> 불완전 메소드
-
-    public void move() { // 일반 메소드도 작성 가능
-        System.out.println("이동한다.");
-    }
-}
diff --git a/JavaOOP/src/poly/Cat.java b/JavaOOP/src/poly/Cat.java
deleted file mode 100644
index 01bfa43a..00000000
--- a/JavaOOP/src/poly/Cat.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package poly;
-
-public class Cat extends Animal {
-    @Override
-    public void eat() {
-        System.out.println("고양이가 먹는다");
-    }
-
-    public void say() {
-        System.out.println("냐옹옹");
-    }
-}
diff --git a/JavaOOP/src/poly/Dog.java b/JavaOOP/src/poly/Dog.java
deleted file mode 100644
index 120349ff..00000000
--- a/JavaOOP/src/poly/Dog.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package poly;
-
-public class Dog extends Animal {
-    @Override
-    public void eat() {
-        System.out.println("개가 먹는다");
-    }
-}
diff --git a/JavaOOP/src/poly/Radio.java b/JavaOOP/src/poly/Radio.java
deleted file mode 100644
index 7a9d0f01..00000000
--- a/JavaOOP/src/poly/Radio.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package poly;
-
-public class Radio implements RemoCon{
-    @Override
-    public void chUp() {
-        System.out.println("Radio 채널이 올라간다.");
-    }
-
-    @Override
-    public void chDown() {
-        System.out.println("Radio 채널이 내려간다.");
-    }
-
-    @Override
-    public void internet() {
-        System.out.println("Radio는 인터넷 사용 불가");
-    }
-}
diff --git a/JavaOOP/src/poly/RemoCon.java b/JavaOOP/src/poly/RemoCon.java
deleted file mode 100644
index c50c013c..00000000
--- a/JavaOOP/src/poly/RemoCon.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package poly;
-
-public interface RemoCon { // 객체 생성 X : RemoCon r = new RemoCon(); (X)
-
-    // 상수를 사용가능 ( public static final 생략 )
-    int MAXCH = 100;
-    int MINCH = 1;
-
-    // public abstract 생략
-    void chUp();
-    void chDown();
-    void internet();
-}
diff --git a/JavaOOP/src/poly/TV.java b/JavaOOP/src/poly/TV.java
deleted file mode 100644
index 48774e70..00000000
--- a/JavaOOP/src/poly/TV.java
+++ /dev/null
@@ -1,29 +0,0 @@
-package poly;
-
-public class TV implements RemoCon{
-    int currCH = 95;
-    @Override
-    public void chUp() {
-        if (currCH < RemoCon.MAXCH) {
-            currCH++;
-        } else {
-            currCH = 1;
-        }
-        System.out.println("TV의 채널이 올라간다. : " + currCH);
-    }
-
-    @Override
-    public void chDown() {
-        if (currCH > RemoCon.MINCH) {
-            currCH--;
-        } else {
-            currCH = RemoCon.MAXCH;
-        }
-        System.out.println("TV의 채널이 내려간다. : " + currCH);
-    }
-
-    @Override
-    public void internet() {
-        System.out.println("TV는 인터넷 사용 가능");
-    }
-}