HikariCP (eugenp#1851)

* jvm log forging

* jvm log forging

* jvm log forging

* log forging

* adding hikariCP module

* try-with-resources

* adding employee use case

* moving HikariCP to libraries

Author: AbhinabKanrar

core-java/pom.xml

@@ -178,19 +178,6 @@
 			<version>2.1.0.1</version>
 		</dependency>
 
-		<dependency>
-			<groupId>com.zaxxer</groupId>
-			<artifactId>HikariCP</artifactId>
-			<version>2.6.1</version>
-			<scope>compile</scope>
-		</dependency>
-
-		<dependency>
-			<groupId>org.postgresql</groupId>
-			<artifactId>postgresql</artifactId>
-			<version>42.0.0</version>
-		</dependency>
-
 	</dependencies>
 
 	<build>

libraries/pom.xml

@@ -231,6 +231,17 @@
             <artifactId>datanucleus-xml</artifactId>
             <version>5.0.0-release</version>
         </dependency>
+		<dependency>
+			<groupId>com.zaxxer</groupId>
+			<artifactId>HikariCP</artifactId>
+			<version>2.6.1</version>
+			<scope>compile</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.postgresql</groupId>
+			<artifactId>postgresql</artifactId>
+			<version>42.0.0</version>
+		</dependency>
     </dependencies>
 
     <properties>

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

@@ -0,0 +1,48 @@
+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;
+
+public class DataSource {
+
+	private static HikariConfig config = new HikariConfig();
+	private static HikariDataSource ds;
+
+	static {
+//		config = new HikariConfig("datasource.properties");
+		
+//		Properties props = new Properties();
+//		props.setProperty("dataSourceClassName", "org.postgresql.ds.PGSimpleDataSource");
+//		props.setProperty("dataSource.user", "postgres");
+//		props.setProperty("dataSource.password", "postgres");
+//		props.setProperty("dataSource.databaseName", "postgres");
+//		props.setProperty("dataSource.portNumber", "5432");
+//		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.setUsername("postgres");
+		config.setPassword("postgres");
+		config.addDataSourceProperty("cachePrepStmts", "true");
+		config.addDataSourceProperty("prepStmtCacheSize", "250");
+		config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048");
+		ds = new HikariDataSource(config);
+		
+//		ds.setJdbcUrl("jdbc:postgresql://localhost:5432/postgres");
+//		ds.setUsername("postgres");
+//		ds.setPassword("postgres");
+	}
+
+	private DataSource() {}
+
+	public static Connection getConnection() throws SQLException {
+		return ds.getConnection();
+	}
+
+}

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

@@ -0,0 +1,72 @@
+package com.baeldung.hikaricp;
+
+import java.sql.Date;
+
+public class Employee {
+
+	private int empNo;
+	private String ename;
+	private String job;
+	private int mgr;
+	private Date hiredate;
+	private int sal;
+	private int comm;
+	private int deptno;
+
+	public int getEmpNo() {
+		return empNo;
+	}
+	public void setEmpNo(int empNo) {
+		this.empNo = empNo;
+	}
+	public String getEname() {
+		return ename;
+	}
+	public void setEname(String ename) {
+		this.ename = ename;
+	}
+	
+	public String getJob() {
+		return job;
+	}
+	public void setJob(String job) {
+		this.job = job;
+	}
+	public int getMgr() {
+		return mgr;
+	}
+	public void setMgr(int mgr) {
+		this.mgr = mgr;
+	}
+	public Date getHiredate() {
+		return hiredate;
+	}
+	public void setHiredate(Date hiredate) {
+		this.hiredate = hiredate;
+	}
+	public int getSal() {
+		return sal;
+	}
+	public void setSal(int sal) {
+		this.sal = sal;
+	}
+	public int getComm() {
+		return comm;
+	}
+	public void setComm(int comm) {
+		this.comm = comm;
+	}
+	public int getDeptno() {
+		return deptno;
+	}
+	public void setDeptno(int deptno) {
+		this.deptno = deptno;
+	}
+
+	@Override
+	public String toString() {
+		return "Employee [empNo=" + empNo + ", ename=" + ename + ", job=" + job + ", mgr=" + mgr + ", hiredate="
+				+ hiredate + ", sal=" + sal + ", comm=" + comm + ", deptno=" + deptno + "]";
+	}
+	
+}

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

@@ -0,0 +1,38 @@
+package com.baeldung.hikaricp;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+
+public class HikariCPDemo {
+
+	public static List<Employee> fetchData() {
+		final String SQL_QUERY = "select * from emp";
+		List<Employee> employees = null;
+		try (Connection con = DataSource.getConnection();
+				PreparedStatement pst = con.prepareStatement(SQL_QUERY);
+				ResultSet rs = pst.executeQuery();) {
+			employees = new ArrayList<Employee>();
+			Employee employee;
+			while (rs.next()) {
+				employee = new Employee();
+				employee.setEmpNo(rs.getInt("empno"));
+				employee.setEname(rs.getString("ename"));
+				employee.setJob(rs.getString("job"));
+				employee.setMgr(rs.getInt("mgr"));
+				employee.setHiredate(rs.getDate("hiredate"));
+				employee.setSal(rs.getInt("sal"));
+				employee.setComm(rs.getInt("comm"));
+				employee.setDeptno(rs.getInt("deptno"));
+				employees.add(employee);
+			}
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+		return employees;
+	}
+
+}

libraries/src/main/java/com/baeldung/hikaricp/db.sql

@@ -0,0 +1,47 @@
+create table dept(
+  deptno numeric,
+  dname  varchar(14),
+  loc    varchar(13),
+  constraint pk_dept primary key (deptno)
+);
+ 
+create table emp(
+  empno    numeric,
+  ename    varchar(10),
+  job      varchar(9),
+  mgr      numeric,
+  hiredate date,
+  sal      numeric,
+  comm     numeric,
+  deptno   numeric,
+  constraint pk_emp primary key (empno),
+  constraint fk_deptno foreign key (deptno) references dept (deptno)
+);
+
+insert into dept values(10, 'ACCOUNTING', 'NEW YORK');
+insert into dept values(20, 'RESEARCH', 'DALLAS');
+insert into dept values(30, 'SALES', 'CHICAGO');
+insert into dept values(40, 'OPERATIONS', 'BOSTON');
+ 
+insert into emp values(
+ 7839, 'KING', 'PRESIDENT', null,
+ to_date('17-11-1981','dd-mm-yyyy'),
+ 7698, null, 10
+);
+insert into emp values(
+ 7698, 'BLAKE', 'MANAGER', 7839,
+ to_date('1-5-1981','dd-mm-yyyy'),
+ 7782, null, 20
+);
+insert into emp values(
+ 7782, 'CLARK', 'MANAGER', 7839,
+ to_date('9-6-1981','dd-mm-yyyy'),
+ 7566, null, 30
+);
+insert into emp values(
+ 7566, 'JONES', 'MANAGER', 7839,
+ to_date('2-4-1981','dd-mm-yyyy'),
+ 7839, null, 40
+);
+
+commit;

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

@@ -0,0 +1,19 @@
+package com.baeldung.hikaricp;
+
+import java.util.List;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class HikariCPTest {
+
+	@Test
+	@Ignore
+    public void givenConnection_thenFetchDbData() {
+		List<Employee> employees = HikariCPDemo.fetchData();
+		assertEquals(4, employees.size());
+	}
+	
+}