[JDBC 라이브러리 구현하기 - 1단계] 파워(송재백) 미션 제출합니다. (#272)

* feat: UserDao 작성 * feat: JdbcTemplate query, queryForObject 구현 * feat: JdbcTemplate update 구현
woowacourse · Sep 28, 2023 · 5540e2b · 5540e2b
1 parent 06379e5
commit 5540e2b
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Showing 3 changed files with 178 additions and 86 deletions.
diff --git a/app/src/main/java/com/techcourse/dao/UserDao.java b/app/src/main/java/com/techcourse/dao/UserDao.java
@@ -1,121 +1,75 @@
 package com.techcourse.dao;
 
 import com.techcourse.domain.User;
-import org.springframework.jdbc.core.JdbcTemplate;
+import java.util.List;
+import javax.sql.DataSource;
 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;
 
 public class UserDao {
 
     private static final Logger log = LoggerFactory.getLogger(UserDao.class);
 
     private final DataSource dataSource;
+    private final JdbcTemplate jdbcTemplate;
 
     public UserDao(final DataSource dataSource) {
         this.dataSource = dataSource;
+        this.jdbcTemplate = new JdbcTemplate(dataSource);
     }
 
     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) {}
-        }
+        String sql = "insert into users (account, password, email) values (?, ?, ?)";
+
+        jdbcTemplate.update(sql, user.getAccount(), user.getPassword(), user.getEmail());
     }
 
     public void update(final User user) {
-        // todo
+        String sql = "update users set id = ?, account = ?, password = ?, email = ? where id = ?";
+
+        jdbcTemplate.update(sql,
+                user.getId(),
+                user.getAccount(),
+                user.getPassword(),
+                user.getEmail(),
+                user.getId()
+        );
     }
 
     public List<User> findAll() {
-        // todo
-        return null;
+        String sql = "select id, account, password, email from users";
+
+        return jdbcTemplate.query(sql, rs -> new User(
+                rs.getLong(1),
+                rs.getString(2),
+                rs.getString(3),
+                rs.getString(4)));
     }
 
     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, rs -> new User(
+                rs.getLong(1),
+                rs.getString(2),
+                rs.getString(3),
+                rs.getString(4)), id);
     }
 
     public User findByAccount(final String account) {
-        // todo
-        return null;
+        String sql = "select id, account, password, email from users where account = ?";
+
+        return jdbcTemplate.queryForObject(sql, rs -> new User(
+                rs.getLong("id"),
+                rs.getString("account"),
+                rs.getString("password"),
+                rs.getString("email")
+        ), account);
     }
 }
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 +1,15 @@
 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.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 +19,127 @@ public class JdbcTemplate {
     public JdbcTemplate(final DataSource dataSource) {
         this.dataSource = dataSource;
     }
+
+    public <T> T queryForObject(String sql, RowMapper<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.mapRow(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(String sql, RowMapper<T> rowMapper) {
+        Connection conn = null;
+        PreparedStatement pstmt = null;
+        ResultSet rs = null;
+        try {
+            conn = dataSource.getConnection();
+            pstmt = conn.prepareStatement(sql);
+
+            rs = pstmt.executeQuery();
+
+            log.debug("query : {}", sql);
+            ArrayList<T> objects = new ArrayList<>();
+            while (rs.next()) {
+                objects.add(rowMapper.mapRow(rs));
+            }
+            return objects;
+        } 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 int update(String sql, 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]);
+            }
+
+            return 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) {
+            }
+        }
+    }
 }
diff --git a/jdbc/src/main/java/org/springframework/jdbc/core/RowMapper.java b/jdbc/src/main/java/org/springframework/jdbc/core/RowMapper.java
@@ -0,0 +1,10 @@
+package org.springframework.jdbc.core;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+@FunctionalInterface
+public interface RowMapper<T> {
+
+    T mapRow(ResultSet rs) throws SQLException;
+}