3장: JDBC 전략 패턴의 최적화

deleteAll() 메소드와 같이 add()를 전략 패턴 적용해보자.
add()에서는 user라는 부가정보가 필요하고, 해당 오브젝트를 받을 수 있도록 AddStatement를 생성하였다.

하지만, 두 가지 문제가 찜찜하다.
1. dao의 메소드 마다 새로운 statementStrategy 구현 클래스를 만들어야 한다.
2. 부가정보가 있는 경우 이를 위해 오브젝트를 전달받는 생성자와 이를 저장해 둘 인스턴스 변수를 번거롭게 만들어야 한다.

src/main/java/com/toby/tobyspring/user/dao/AddStatement.java

@@ -0,0 +1,25 @@
+package com.toby.tobyspring.user.dao;
+
+import com.toby.tobyspring.user.domain.User;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+
+public class AddStatement implements StatementStrategy {
+    User user;
+
+    public AddStatement(User user) {
+        this.user = user;
+    }
+
+    @Override
+    public PreparedStatement makePreparedStatement(Connection connection) throws SQLException {
+        PreparedStatement preparedStatement = connection.prepareStatement("insert into users(id, name, password) values(?, ?, ?)");
+        preparedStatement.setString(1, user.getId());
+        preparedStatement.setString(2, user.getName());
+        preparedStatement.setString(3, user.getPassword());
+
+        return preparedStatement;
+    }
+}

src/main/java/com/toby/tobyspring/user/dao/DeleteAllStrategy.java → src/main/java/com/toby/tobyspring/user/dao/DeleteAllStatement.java

@@ -4,7 +4,7 @@
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 
-public class DeleteAllStrategy implements StatementStrategy {
+public class DeleteAllStatement implements StatementStrategy {
     @Override
     public PreparedStatement makePreparedStatement(Connection connection) throws SQLException {
         return connection.prepareStatement("delete from users");

src/main/java/com/toby/tobyspring/user/dao/UserDao.java

@@ -17,18 +17,8 @@ public void setDataSource(DataSource dataSource) {
     }
 
     public void add(User user) throws SQLException {
-        Connection connection = dataSource.getConnection();
-        // sql 실행
-        PreparedStatement preparedStatement = connection.prepareStatement("insert into users(id, name, password) values(?, ?, ?)");
-        preparedStatement.setString(1, user.getId());
-        preparedStatement.setString(2, user.getName());
-        preparedStatement.setString(3, user.getPassword());
-
-        preparedStatement.executeUpdate();
-
-        // 자원 회수
-        preparedStatement.close();
-        connection.close();
+        StatementStrategy statementStrategy = new AddStatement(user);
+        this.jdbcContextWithStatementStrategy(statementStrategy);
     }
 
     public User get(String id) throws SQLException {
@@ -95,7 +85,7 @@ public int getCount() throws SQLException {
     }
 
     public void deleteAll() throws SQLException {
-        StatementStrategy statementStrategy = new DeleteAllStrategy();
+        StatementStrategy statementStrategy = new DeleteAllStatement();
         this.jdbcContextWithStatementStrategy(statementStrategy);
     }