feat: jdbc 템플릿 구현

woowacourse · Sep 26, 2023 · 32716b0 · 32716b0
1 parent 7619252
commit 32716b0
Show file tree

Hide file tree

Showing 3 changed files with 172 additions and 135 deletions.
diff --git a/app/src/main/java/com/techcourse/dao/UserDao.java b/app/src/main/java/com/techcourse/dao/UserDao.java
@@ -1,171 +1,67 @@
 package com.techcourse.dao;
 
 import com.techcourse.domain.User;
-import java.util.ArrayList;
-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 java.util.function.Function;
+import javax.sql.DataSource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.jdbc.core.JdbcTemplate;
 
 public class UserDao {
 
     private static final Logger log = LoggerFactory.getLogger(UserDao.class);
+    private static final Function<ResultSet, User> ROW_MAPPER = rs -> {
+        try {
+            return new User(
+                    rs.getLong("id"),
+                    rs.getString("account"),
+                    rs.getString("password"),
+                    rs.getString("email"));
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+    };
 
     private final DataSource dataSource;
+    private final JdbcTemplate jdbcTemplate;
 
     public UserDao(final DataSource dataSource) {
         this.dataSource = dataSource;
+        this.jdbcTemplate = null;
     }
 
     public UserDao(final JdbcTemplate jdbcTemplate) {
-        this.dataSource = null;
+        this.dataSource = jdbcTemplate.getDataSource();
+        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) {}
+        final String sql = "insert into users (account, password, email) values (?, ?, ?)";
 
-            try {
-                if (conn != null) {
-                    conn.close();
-                }
-            } catch (SQLException ignored) {}
-        }
+        jdbcTemplate.execute(sql, user.getAccount(), user.getPassword(), user.getEmail());
     }
 
     public void update(final User user) {
         final var sql = "update users set account = ?, email = ?, password = ? where id = ?";
 
-        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.getEmail());
-            pstmt.setString(3, user.getPassword());
-            pstmt.setLong(4, user.getId());
-            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) {}
-        }
-
+        jdbcTemplate.execute(sql, user.getAccount(), user.getEmail(), user.getPassword(), user.getId());
     }
 
     public List<User> findAll() {
         final String sql = "select * from users";
-        List<User> users = new ArrayList<>();
-        Connection conn;
-        PreparedStatement pstmt;
-        ResultSet rs;
-        try {
-            conn = dataSource.getConnection();
-            pstmt = conn.prepareStatement(sql);
-            rs = pstmt.executeQuery();
-
-            log.debug("query : {}", sql);
 
-            while (rs.next()) {
-                users.add(new User(
-                        rs.getLong(1),
-                        rs.getString(2),
-                        rs.getString(3),
-                        rs.getString(4)));
-            }
-            return users;
-        } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new RuntimeException(e);
-        }
+        return jdbcTemplate.query(sql, 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) {}
-        }
+        return jdbcTemplate.queryForObject(sql, ROW_MAPPER, id);
     }
 
     public User findByAccount(final String account) {
@@ -198,19 +94,22 @@ public User findByAccount(final String account) {
                 if (rs != null) {
                     rs.close();
                 }
-            } catch (SQLException ignored) {}
+            } catch (SQLException ignored) {
+            }
 
             try {
                 if (pstmt != null) {
                     pstmt.close();
                 }
-            } catch (SQLException ignored) {}
+            } catch (SQLException ignored) {
+            }
 
             try {
                 if (conn != null) {
                     conn.close();
                 }
-            } catch (SQLException ignored) {}
+            } catch (SQLException ignored) {
+            }
         }
     }
 }
diff --git a/app/src/test/java/com/techcourse/dao/UserDaoTest.java b/app/src/test/java/com/techcourse/dao/UserDaoTest.java
@@ -5,6 +5,7 @@
 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;
 
@@ -16,7 +17,8 @@ class UserDaoTest {
     void setup() {
         DatabasePopulatorUtils.execute(DataSourceConfig.getInstance());
 
-        userDao = new UserDao(DataSourceConfig.getInstance());
+//        userDao = new UserDao(DataSourceConfig.getInstance());
+        userDao = new UserDao(new JdbcTemplate(DataSourceConfig.getInstance()));
         final var user = new User("gugu", "password", "[email protected]");
         userDao.insert(user);
     }

diff --git a/jdbc/src/main/java/org/springframework/jdbc/core/JdbcTemplate.java b/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 java.util.function.Function;
+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 +20,134 @@ public class JdbcTemplate {
     public JdbcTemplate(final DataSource dataSource) {
         this.dataSource = dataSource;
     }
+
+    public void execute(final String sql, final Object... args) {
+        Connection conn = null;
+        PreparedStatement pstmt = null;
+        try {
+            conn = dataSource.getConnection();
+            pstmt = conn.prepareStatement(sql);
+
+            log.debug("query : {}", sql);
+
+            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> T queryForObject(final String sql, Function<ResultSet, T> rowMapper, Object... args) {
+        Connection conn = null;
+        PreparedStatement pstmt = null;
+        ResultSet rs = null;
+        try {
+            conn = dataSource.getConnection();
+            pstmt = conn.prepareStatement(sql);
+            for (int i = 0; i < args.length; i++) {
+                pstmt.setObject(i + 1, args[i]);
+            }
+            rs = pstmt.executeQuery();
+
+            log.debug("query : {}", sql);
+
+            if (rs.next()) {
+                return rowMapper.apply(rs);
+            }
+            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) {
+            }
+        }
+    }
+
+    public <T> List<T> query(final String sql, Function<ResultSet, T> rowMapper, Object... args) {
+        List<T> result = new ArrayList<>();
+
+        Connection conn = null;
+        PreparedStatement pstmt = null;
+        ResultSet rs = null;
+        try {
+            conn = dataSource.getConnection();
+            pstmt = conn.prepareStatement(sql);
+            for (int i = 0; i < args.length; i++) {
+                pstmt.setObject(i + 1, args[i]);
+            }
+            rs = pstmt.executeQuery();
+
+            log.debug("query : {}", sql);
+
+            while (rs.next()) {
+                result.add(rowMapper.apply(rs));
+            }
+        } 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 result;
+    }
+
+    public DataSource getDataSource() {
+        return dataSource;
+    }
 }