[라이브러리 구현하기 - 2단계] 헙크(정현승) 미션 제출합니다. (#351)

* refactor: `PreparedStatementSetter` 구현

* refactor: 기존 코드로 원복

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

@@ -1,8 +1,6 @@
 package com.techcourse.dao;
 
 import com.techcourse.domain.User;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.core.RowMapper;
 

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

@@ -18,7 +18,7 @@ public JdbcTemplate(final DataSource dataSource) {
         this.dataSource = dataSource;
     }
 
-    public <T> Optional<T> queryForObject(final String sql, final RowMapper<T> rowMapper, Object... args) {
+    public <T> Optional<T> queryForObject(final String sql, final RowMapper<T> rowMapper, final Object... args) {
         try (final Connection conn = dataSource.getConnection();
              final PreparedStatement pstmt = conn.prepareStatement(sql)) {
             for (int i = 0; i < args.length; i++) {
@@ -35,7 +35,7 @@ public <T> Optional<T> queryForObject(final String sql, final RowMapper<T> rowMa
         }
     }
 
-    public <T> List<T> query(String sql, RowMapper<T> rowMapper) throws DataAccessException {
+    public <T> List<T> query(final String sql, final RowMapper<T> rowMapper) throws DataAccessException {
         try (final Connection conn = dataSource.getConnection();
              final PreparedStatement pstmt = conn.prepareStatement(sql)) {
             final List<T> result = new ArrayList<>();

jdbc/src/main/java/org/springframework/jdbc/core/exception/InvalidResultSetAccessException.java

@@ -0,0 +1,20 @@
+package org.springframework.jdbc.core.exception;
+
+/**
+ * ResultSet이 잘못된 방식으로 접근되었을 때 발생하는 예외.
+ * 이는 일반적으로 잘못된 ResultSet 열 인덱스 또는 이름이 지정되었을 때 발생합니다.
+ * 또한 연결이 끊긴 SqlRowSets에 의해 발생되기도 합니다.
+ */
+public class InvalidResultSetAccessException extends RuntimeException {
+    public InvalidResultSetAccessException(final String reason) {
+        super(reason);
+    }
+
+    public InvalidResultSetAccessException() {
+        super();
+    }
+
+    public InvalidResultSetAccessException(final String reason, final Throwable cause) {
+        super(reason, cause);
+    }
+}

study/src/test/java/connectionpool/PoolingVsNoPoolingTest.java

@@ -30,7 +30,7 @@ class PoolingVsNoPoolingTest {
 
     private final Logger log = LoggerFactory.getLogger(PoolingVsNoPoolingTest.class);
 
-    private static final int COUNT = 1000;
+    private static final int COUNT = 10000;
 
     private static MySQLContainer<?> container;
 
@@ -78,9 +78,12 @@ void pooling() throws SQLException {
         config.setJdbcUrl(container.getJdbcUrl());
         config.setUsername(container.getUsername());
         config.setPassword(container.getPassword());
-        config.setMinimumIdle(1);
-        config.setMaximumPoolSize(1);
+        config.setMinimumIdle(10);
+        config.setMaximumPoolSize(10);
         config.setConnectionTimeout(1000);
+        config.addDataSourceProperty("cachePrepStmts", "true");
+        config.addDataSourceProperty("prepStmtCacheSize", "250");
+        config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048");
         config.setAutoCommit(false);
         config.setReadOnly(false);
         final var hikariDataSource = new HikariDataSource(config);