[JDBC 라이브러리 구현하기 - 1단계] 후추(주찬민) 미션 제출합니다.

README.md

@@ -1 +1,12 @@
 # JDBC 라이브러리 구현하기
+
+## 1단계 - JDBC 라이브러리 구현하기
+
+- [x] JDBC Template 구현
+    - [x] 데이터 변경 쿼리에 대한 메서드
+    - [x] 단일 객체 조회 쿼리에 대한 메서드
+    - [x] 복수 객체 조회 쿼리에 대한 메서드
+
+- [x] UserDao 리팩터링
+
+

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

@@ -1,121 +1,48 @@
 package com.techcourse.dao;
 
 import com.techcourse.domain.User;
-import org.springframework.jdbc.core.JdbcTemplate;
-import org.slf4j.Logger;
-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.List;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.core.RowMapper;
 
 public class UserDao {
 
-    private static final Logger log = LoggerFactory.getLogger(UserDao.class);
+    private static final RowMapper<User> USER_ROW_MAPPER = rs -> {
+        final long userId = rs.getLong("id");
+        final String account = rs.getString("account");
+        final String password = rs.getString("password");
+        final String email = rs.getString("email");
+        return new User(userId, account, password, email);
+    };
 
-    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);
-
-            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) {}
-        }
+        final var sql = "INSERT INTO users (account, password, email) VALUES (?, ?, ?)";
+        jdbcTemplate.update(sql, user.getAccount(), user.getPassword(), user.getEmail());
     }
 
     public void update(final User user) {
-        // todo
+        final var sql = "UPDATE users SET account = ?, password = ?, email = ? WHERE id = ?";
+        jdbcTemplate.update(sql, user.getAccount(), user.getPassword(), user.getEmail(), user.getId());
     }
 
     public List<User> findAll() {
-        // todo
-        return null;
+        final var sql = "SELECT id, account, password, email FROM users";
+        return jdbcTemplate.query(sql, USER_ROW_MAPPER);
     }
 
     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) {}
-        }
+        final var sql = "SELECT id, account, password, email FROM users WHERE id = ?";
+        return jdbcTemplate.queryForObject(sql, USER_ROW_MAPPER, id);
     }
 
     public User findByAccount(final String account) {
-        // todo
-        return null;
+        final var sql = "SELECT id, account, password, email FROM users WHERE account = ?";
+        return jdbcTemplate.queryForObject(sql, USER_ROW_MAPPER, account);
     }
 }

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

@@ -1,69 +1,113 @@
 package com.techcourse.dao;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.SoftAssertions.assertSoftly;
+
 import com.techcourse.config.DataSourceConfig;
 import com.techcourse.domain.User;
 import com.techcourse.support.jdbc.init.DatabasePopulatorUtils;
+import java.util.List;
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayNameGeneration;
+import org.junit.jupiter.api.DisplayNameGenerator;
 import org.junit.jupiter.api.Test;
+import org.springframework.jdbc.core.JdbcTemplate;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
+@SuppressWarnings("NonAsciiCharacters")
+@DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
 class UserDaoTest {
 
+    private JdbcTemplate jdbcTemplate;
+    private User user;
     private UserDao userDao;
 
     @BeforeEach
     void setup() {
         DatabasePopulatorUtils.execute(DataSourceConfig.getInstance());
+        jdbcTemplate = new JdbcTemplate(DataSourceConfig.getInstance());
+        userDao = new UserDao(jdbcTemplate);
 
-        userDao = new UserDao(DataSourceConfig.getInstance());
-        final var user = new User("gugu", "password", "[email protected]");
-        userDao.insert(user);
+        userDao.insert(new User("gugu", "password", "[email protected]"));
+        user = userDao.findByAccount("gugu");
     }
 
     @Test
-    void findAll() {
-        final var users = userDao.findAll();
-
-        assertThat(users).isNotEmpty();
+    void 모든_회원을_조회한다() {
+        // when
+        final List<User> users = userDao.findAll();
+
+        // then
+        assertSoftly(softly -> {
+            softly.assertThat(users).hasSize(1);
+            final User user = users.get(0);
+
+            softly.assertThat(user.getAccount()).isEqualTo("gugu");
+            softly.assertThat(user.getPassword()).isEqualTo("password");
+            softly.assertThat(user.getEmail()).isEqualTo("[email protected]");
+        });
     }
 
     @Test
-    void findById() {
-        final var user = userDao.findById(1L);
-
-        assertThat(user.getAccount()).isEqualTo("gugu");
+    void ID로_회원을_조회한다() {
+        // when
+        final User foundUser = userDao.findById(user.getId());
+
+        // then
+        assertSoftly(softly -> {
+            softly.assertThat(foundUser.getAccount()).isEqualTo("gugu");
+            softly.assertThat(foundUser.getPassword()).isEqualTo("password");
+            softly.assertThat(foundUser.getEmail()).isEqualTo("[email protected]");
+        });
     }
 
     @Test
-    void findByAccount() {
-        final var account = "gugu";
-        final var user = userDao.findByAccount(account);
-
-        assertThat(user.getAccount()).isEqualTo(account);
+    void 계정으로_회원을_조회한다() {
+        // when
+        final User foundUser = userDao.findByAccount(user.getAccount());
+
+        // then
+        assertSoftly(softly -> {
+            softly.assertThat(foundUser.getAccount()).isEqualTo("gugu");
+            softly.assertThat(foundUser.getPassword()).isEqualTo("password");
+            softly.assertThat(foundUser.getEmail()).isEqualTo("[email protected]");
+        });
     }
 
     @Test
-    void insert() {
-        final var account = "insert-gugu";
-        final var user = new User(account, "password", "[email protected]");
-        userDao.insert(user);
-
-        final var actual = userDao.findById(2L);
-
-        assertThat(actual.getAccount()).isEqualTo(account);
+    void 회원을_정보를_입력한다() {
+        // given
+        final var account = "huchu";
+        final User huchu = new User(account, "password", "[email protected]");
+
+        // when
+        userDao.insert(huchu);
+
+        // then
+        final User foundUser = userDao.findByAccount(account);
+        assertSoftly(softly -> {
+            softly.assertThat(foundUser.getAccount()).isEqualTo("huchu");
+            softly.assertThat(foundUser.getPassword()).isEqualTo("password");
+            softly.assertThat(foundUser.getEmail()).isEqualTo("[email protected]");
+        });
     }
 
     @Test
-    void update() {
-        final var newPassword = "password99";
-        final var user = userDao.findById(1L);
-        user.changePassword(newPassword);
+    void 회원_정보를_수정한다() {
+        // given
+        user.changePassword("newPassword");
 
+        // when
         userDao.update(user);
 
-        final var actual = userDao.findById(1L);
+        // then
+        final User changedUser = userDao.findByAccount(user.getAccount());
+        assertThat(changedUser.getPassword()).isEqualTo("newPassword");
+    }
 
-        assertThat(actual.getPassword()).isEqualTo(newPassword);
+    @AfterEach
+    void tearDown() {
+        final String deleteSql = "DELETE FROM users";
+        jdbcTemplate.update(deleteSql);
     }
 }

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

@@ -1,10 +1,16 @@
 package org.springframework.jdbc.core;
 
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+import javax.annotation.Nullable;
+import javax.sql.DataSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import javax.sql.DataSource;
-
 public class JdbcTemplate {
 
     private static final Logger log = LoggerFactory.getLogger(JdbcTemplate.class);
@@ -14,4 +20,70 @@ public class JdbcTemplate {
     public JdbcTemplate(final DataSource dataSource) {
         this.dataSource = dataSource;
     }
+
+    public int update(String sql, Object... args) {
+        try (
+                Connection conn = dataSource.getConnection();
+                PreparedStatement pstmt = conn.prepareStatement(sql)
+        ) {
+            log.debug("query : {}", sql);
+
+            setParameters(pstmt, args);
+
+            return pstmt.executeUpdate();
+        } catch (SQLException e) {
+            log.error(e.getMessage(), e);
+            throw new RuntimeException(e);
+        }
+    }
+
+    private void setParameters(PreparedStatement pstmt, Object[] args) throws SQLException {
+        for (int i = 0; i < args.length; i++) {
+            pstmt.setObject(i + 1, args[i]);
+        }
+    }
+
+    @Nullable
+    public <T> T queryForObject(String sql, RowMapper<T> rowMapper, Object... args) {
+        try (
+                Connection conn = dataSource.getConnection();
+                PreparedStatement pstmt = conn.prepareStatement(sql)
+        ) {
+            log.debug("query : {}", sql);
+
+            setParameters(pstmt, args);
+
+            try (ResultSet resultSet = pstmt.executeQuery()) {
+                if (resultSet.next()) {
+                    return rowMapper.mapRow(resultSet);
+                }
+            }
+            return null;
+        } catch (SQLException e) {
+            log.error(e.getMessage(), e);
+            throw new RuntimeException(e);
+        }
+    }
+
+    public <T> List<T> query(String sql, RowMapper<T> rowMapper, Object... args) {
+        try (
+                Connection conn = dataSource.getConnection();
+                PreparedStatement pstmt = conn.prepareStatement(sql)
+        ) {
+            log.debug("query : {}", sql);
+
+            setParameters(pstmt, args);
+
+            try (ResultSet resultSet = pstmt.executeQuery()) {
+                List<T> results = new ArrayList<>();
+                while (resultSet.next()) {
+                    results.add(rowMapper.mapRow(resultSet));
+                }
+                return results;
+            }
+        } catch (SQLException e) {
+            log.error(e.getMessage(), e);
+            throw new RuntimeException(e);
+        }
+    }
 }