[JDBC 라이브러리 구현하기 - 1단계] 제나(위예나) 미션 제출합니다

README.md

@@ -1 +1,8 @@
 # JDBC 라이브러리 구현하기
+
+## 1단계
+- [x] UserDaoTest 성공시키기
+  - [x] update()
+  - [x] findAll()
+  - [x] findByAccount()
+- [x] 중복 코드는 JdbcTemplate 에 추출하기

app/src/main/java/com/techcourse/dao/UserDao.java

@@ -1,13 +1,11 @@
 package com.techcourse.dao;
 
 import com.techcourse.domain.User;
-import org.springframework.jdbc.core.JdbcTemplate;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.core.RowMapper;
 
-import javax.sql.DataSource;
-import java.sql.Connection;
-import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.List;
@@ -16,106 +14,45 @@ public class UserDao {
 
     private static final Logger log = LoggerFactory.getLogger(UserDao.class);
 
-    private final DataSource dataSource;
-
-    public UserDao(final DataSource dataSource) {
-        this.dataSource = dataSource;
-    }
+    private final JdbcTemplate jdbcTemplate;
 
     public UserDao(final JdbcTemplate jdbcTemplate) {
-        this.dataSource = null;
+        this.jdbcTemplate = jdbcTemplate;
     }
 
-    public void insert(final User user) {
-        final var sql = "insert into users (account, password, email) values (?, ?, ?)";
-
-        Connection conn = null;
-        PreparedStatement pstmt = null;
-        try {
-            conn = dataSource.getConnection();
-            pstmt = conn.prepareStatement(sql);
-
-            log.debug("query : {}", sql);
+    public static RowMapper<User> rowMapper = new RowMapper<User>() {
+        @Override
+        public User mapRow(ResultSet rs) throws SQLException {
+            long id = rs.getLong(1);
+            String account = rs.getString(2);
+            String password = rs.getString(3);
+            String email = rs.getString(4);
+            return new User(id, account, password, email);
+        }
+    };
 
-            pstmt.setString(1, user.getAccount());
-            pstmt.setString(2, user.getPassword());
-            pstmt.setString(3, user.getEmail());
-            pstmt.executeUpdate();
-        } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new RuntimeException(e);
-        } finally {
-            try {
-                if (pstmt != null) {
-                    pstmt.close();
-                }
-            } catch (SQLException ignored) {}
 
-            try {
-                if (conn != null) {
-                    conn.close();
-                }
-            } catch (SQLException ignored) {}
-        }
+    public void insert(final User user) {
+        jdbcTemplate.execute("insert into users (account, password, email) values (?, ?, ?)",
+                user.getAccount(), user.getPassword(), user.getEmail());
     }
 
     public void update(final User user) {
-        // todo
+        jdbcTemplate.execute("update users set account = ?, password = ?, email = ? where id = ?",
+                user.getAccount(), user.getPassword(), user.getEmail(), user.getId());
     }
 
     public List<User> findAll() {
-        // todo
-        return null;
+        return jdbcTemplate.query("select id, account, password, email from users", rowMapper);
     }
 
     public User findById(final Long id) {
-        final var sql = "select id, account, password, email from users where id = ?";
-
-        Connection conn = null;
-        PreparedStatement pstmt = null;
-        ResultSet rs = null;
-        try {
-            conn = dataSource.getConnection();
-            pstmt = conn.prepareStatement(sql);
-            pstmt.setLong(1, id);
-            rs = pstmt.executeQuery();
-
-            log.debug("query : {}", sql);
-
-            if (rs.next()) {
-                return new User(
-                        rs.getLong(1),
-                        rs.getString(2),
-                        rs.getString(3),
-                        rs.getString(4));
-            }
-            return null;
-        } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new RuntimeException(e);
-        } finally {
-            try {
-                if (rs != null) {
-                    rs.close();
-                }
-            } catch (SQLException ignored) {}
-
-            try {
-                if (pstmt != null) {
-                    pstmt.close();
-                }
-            } catch (SQLException ignored) {}
-
-            try {
-                if (conn != null) {
-                    conn.close();
-                }
-            } catch (SQLException ignored) {}
-        }
+        return jdbcTemplate.queryForObject("select id, account, password, email from users where id = ?",
+                rowMapper, id);
     }
 
     public User findByAccount(final String account) {
-        // todo
-        return null;
+        return jdbcTemplate.queryForObject("select id, account, password, email from users where account = ?"
+                , rowMapper, account);
     }
 }

app/src/test/java/com/techcourse/dao/UserDaoTest.java

@@ -5,18 +5,21 @@
 import com.techcourse.support.jdbc.init.DatabasePopulatorUtils;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.springframework.jdbc.core.JdbcTemplate;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 class UserDaoTest {
 
     private UserDao userDao;
+    private JdbcTemplate jdbcTemplate;
 
     @BeforeEach
     void setup() {
         DatabasePopulatorUtils.execute(DataSourceConfig.getInstance());
+        jdbcTemplate = new JdbcTemplate(DataSourceConfig.getInstance());
 
-        userDao = new UserDao(DataSourceConfig.getInstance());
+        userDao = new UserDao(jdbcTemplate);
         final var user = new User("gugu", "password", "[email protected]");
         userDao.insert(user);
     }

jdbc/src/main/java/org/springframework/jdbc/core/JdbcTemplate.java

@@ -4,6 +4,12 @@
 import org.slf4j.LoggerFactory;
 
 import javax.sql.DataSource;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
 
 public class JdbcTemplate {
 
@@ -14,4 +20,195 @@ public class JdbcTemplate {
     public JdbcTemplate(final DataSource dataSource) {
         this.dataSource = dataSource;
     }
+
+    public Connection getConnection() throws SQLException {
+        return dataSource.getConnection();
+    }
+
+    public void execute(String sql) {
+        context(new PreparedStrategy() {
+            @Override
+            public PreparedStatement createStatement(Connection connection) throws SQLException {
+                return connection.prepareStatement(sql);
+            }
+        });
+    }
+
+    public void execute(String sql, Object... args) {
+        context(new PreparedStrategy() {
+            @Override
+            public PreparedStatement createStatement(Connection connection) throws SQLException {
+                return connection.prepareStatement(sql);
+            }
+        }, args);
+    }
+
+    public <T> List<T> query(String sql, RowMapper<T> rm) {
+        return context(new PreparedStrategy() {
+            @Override
+            public PreparedStatement createStatement(Connection connection) throws SQLException {
+                return connection.prepareStatement(sql);
+            }
+        }, rm);
+    }
+
+    public <T> T queryForObject(String sql, RowMapper<T> rm, Object... args) {
+        List<T> list = context(new PreparedStrategy() {
+            @Override
+            public PreparedStatement createStatement(Connection connection) throws SQLException {
+                return connection.prepareStatement(sql);
+            }
+        }, rm, args);
+
+        if (list.isEmpty()) {
+            return null;
+        }
+        return list.get(0);
+    }
+
+    public void context(PreparedStrategy preparedStrategy) {
+        Connection conn = null;
+        PreparedStatement pstmt = null;
+        try {
+            conn = dataSource.getConnection();
+            pstmt = preparedStrategy.createStatement(conn);
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            log.error(e.getMessage(), e);
+            throw new RuntimeException(e);
+        } finally {
+            try {
+                if (pstmt != null) {
+                    pstmt.close();
+                }
+            } catch (SQLException ignored) {
+            }
+
+            try {
+                if (conn != null) {
+                    conn.close();
+                }
+            } catch (SQLException ignored) {
+            }
+        }
+    }
+
+    public void context(PreparedStrategy preparedStrategy, Object[] args) {
+        Connection conn = null;
+        PreparedStatement pstmt = null;
+        try {
+            conn = dataSource.getConnection();
+            pstmt = preparedStrategy.createStatement(conn);
+
+            for (int i = 0; i < args.length; i++) {
+                pstmt.setObject(i + 1, args[i]);
+            }
+
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            log.error(e.getMessage(), e);
+            throw new RuntimeException(e);
+        } finally {
+            try {
+                if (pstmt != null) {
+                    pstmt.close();
+                }
+            } catch (SQLException ignored) {
+            }
+
+            try {
+                if (conn != null) {
+                    conn.close();
+                }
+            } catch (SQLException ignored) {
+            }
+        }
+    }
+
+    public <T> List<T> context(PreparedStrategy preparedStrategy, RowMapper<T> rm) {
+        Connection conn = null;
+        PreparedStatement pstmt = null;
+        ResultSet rs = null;
+        try {
+            conn = dataSource.getConnection();
+            pstmt = preparedStrategy.createStatement(conn);
+            rs = pstmt.executeQuery();
+
+            ArrayList<T> list = new ArrayList<>();
+            while (rs.next()) {
+                list.add(rm.mapRow(rs));
+            }
+            return list;
+        } catch (SQLException e) {
+            log.error(e.getMessage(), e);
+            throw new RuntimeException(e);
+        } finally {
+            try {
+                if (rs != null) {
+                    rs.close();
+                }
+            } catch (SQLException ignored) {
+            }
+
+            try {
+                if (pstmt != null) {
+                    pstmt.close();
+                }
+            } catch (SQLException ignored) {
+            }
+
+            try {
+                if (conn != null) {
+                    conn.close();
+                }
+            } catch (SQLException ignored) {
+            }
+        }
+    }
+
+    public <T> List<T> context(PreparedStrategy preparedStrategy, RowMapper<T> rm, Object[] args) {
+        Connection conn = null;
+        PreparedStatement pstmt = null;
+        ResultSet rs = null;
+        try {
+            conn = dataSource.getConnection();
+            pstmt = preparedStrategy.createStatement(conn);
+
+            for (int i = 0; i < args.length; i++) {
+                pstmt.setObject(i + 1, args[i]);
+            }
+
+            rs = pstmt.executeQuery();
+
+            ArrayList<T> list = new ArrayList<>();
+            while (rs.next()) {
+                list.add(rm.mapRow(rs));
+            }
+            return list;
+        } catch (SQLException e) {
+            log.error(e.getMessage(), e);
+            throw new RuntimeException(e);
+        } finally {
+            try {
+                if (rs != null) {
+                    rs.close();
+                }
+            } catch (SQLException ignored) {
+            }
+
+            try {
+                if (pstmt != null) {
+                    pstmt.close();
+                }
+            } catch (SQLException ignored) {
+            }
+
+            try {
+                if (conn != null) {
+                    conn.close();
+                }
+            } catch (SQLException ignored) {
+            }
+        }
+    }
 }

jdbc/src/main/java/org/springframework/jdbc/core/PreparedStrategy.java

@@ -0,0 +1,10 @@
+package org.springframework.jdbc.core;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+
+public interface PreparedStrategy {
+
+    PreparedStatement createStatement(Connection connection) throws SQLException;
+}