final version (#1867)

libraries/pom.xml

@@ -265,9 +265,9 @@
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-            <groupId>org.postgresql</groupId>
+			<groupId>com.h2database</groupId>
-            <artifactId>postgresql</artifactId>
+			<artifactId>h2</artifactId>
-            <version>42.0.0</version>
+			<version>1.4.195</version>
 		</dependency>
 	</dependencies>
 	<properties>

libraries/src/main/java/com/baeldung/hikaricp/DataSource.java

@@ -1,44 +1,42 @@
 package com.baeldung.hikaricp;
 
+import java.io.PrintWriter;
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Properties;
+
 import com.zaxxer.hikari.HikariConfig;
 import com.zaxxer.hikari.HikariDataSource;
 
-import java.sql.Connection;
-import java.sql.SQLException;
-
 public class DataSource {
 
 	private static HikariConfig config = new HikariConfig();
 	private static HikariDataSource ds;
 
 	static {
-       /* config = new HikariConfig("datasource.properties");
+//		config = new HikariConfig("datasource.properties");
 		
-        Properties props = new Properties();
+//		Properties props = new Properties();
-        props.setProperty("dataSourceClassName", "org.postgresql.ds.PGSimpleDataSource");
+//		props.setProperty("dataSourceClassName", "org.h2.Driver");
-        props.setProperty("dataSource.user", "postgres");
+//		props.setProperty("dataSource.user", "");
-        props.setProperty("dataSource.password", "postgres");
+//		props.setProperty("dataSource.password", "");
-        props.setProperty("dataSource.databaseName", "postgres");
+//		props.put("dataSource.logWriter", new PrintWriter(System.out));
-        props.setProperty("dataSource.portNumber", "5432");
+//		config = new HikariConfig(props);
-        props.setProperty("dataSource.serverName", "localhost");
-        props.put("dataSource.logWriter", new PrintWriter(System.out));
-        config = new HikariConfig(props);*/
 		
-        config.setJdbcUrl("jdbc:postgresql://localhost:5432/postgres");
+		config.setJdbcUrl("jdbc:h2:mem:test;DB_CLOSE_DELAY=-1;INIT=runscript from 'classpath:/db.sql'");
-        config.setUsername("postgres");
+		config.setUsername("");
-        config.setPassword("postgres");
+		config.setPassword("");
 		config.addDataSourceProperty("cachePrepStmts", "true");
 		config.addDataSourceProperty("prepStmtCacheSize", "250");
 		config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048");
 		ds = new HikariDataSource(config);
 		
-       /* ds.setJdbcUrl("jdbc:postgresql://localhost:5432/postgres");
+//		ds.setJdbcUrl("jdbc:h2:mem:test;DB_CLOSE_DELAY=-1;INIT=runscript from 'classpath:/db.sql'");
-        ds.setUsername("postgres");
+//		ds.setUsername("");
-        ds.setPassword("postgres");*/
+//		ds.setPassword("");
 	}
 
-    private DataSource() {
+	private DataSource() {}
-    }
 
 	public static Connection getConnection() throws SQLException {
 		return ds.getConnection();

libraries/src/main/java/com/baeldung/hikaricp/HikariCPDemo.java

@@ -9,11 +9,13 @@ import java.util.List;
 
 public class HikariCPDemo {
 
-    public static List<Employee> fetchData() throws SQLException {
+	public static List<Employee> fetchData() {
 		final String SQL_QUERY = "select * from emp";
-        List<Employee> employees;
+		List<Employee> employees = null;
-        try (Connection con = DataSource.getConnection(); PreparedStatement pst = con.prepareStatement(SQL_QUERY); ResultSet rs = pst.executeQuery()) {
+		try (Connection con = DataSource.getConnection();
-            employees = new ArrayList<>();
+				PreparedStatement pst = con.prepareStatement(SQL_QUERY);
+				ResultSet rs = pst.executeQuery();) {
+			employees = new ArrayList<Employee>();
 			Employee employee;
 			while (rs.next()) {
 				employee = new Employee();
@@ -27,8 +29,14 @@ public class HikariCPDemo {
 				employee.setDeptno(rs.getInt("deptno"));
 				employees.add(employee);
 			}
+		} catch (SQLException e) {
+			e.printStackTrace();
 		}
 		return employees;
 	}
 
+	public static void main(String[] args) {
+		fetchData();
+	}
+	
 }

libraries/src/test/java/com/baeldung/hikaricp/HikariCPUnitTest.java

@@ -2,17 +2,14 @@ package com.baeldung.hikaricp;
 
 import java.util.List;
 
-import org.junit.Ignore;
 import org.junit.Test;
-import java.sql.SQLException;
 
 import static org.junit.Assert.assertEquals;
 
 public class HikariCPUnitTest {
 
 	@Test
-    @Ignore
+	public void givenConnection_thenFetchDbData() {
-    public void givenConnection_thenFetchDbData() throws SQLException {
 		List<Employee> employees = HikariCPDemo.fetchData();
 		assertEquals(4, employees.size());
 	}