Refactor

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

@@ -1,30 +1,28 @@
 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();
-//		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);
+        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");
@@ -34,12 +32,13 @@ public class DataSource {
         config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048");
         ds = new HikariDataSource(config);
 
-//		ds.setJdbcUrl("jdbc:postgresql://localhost:5432/postgres");
-//		ds.setUsername("postgres");
-//		ds.setPassword("postgres");
+       /* ds.setJdbcUrl("jdbc:postgresql://localhost:5432/postgres");
+        ds.setUsername("postgres");
+        ds.setPassword("postgres");*/
     }
 
-	private DataSource() {}
+    private DataSource() {
+    }
 
     public static Connection getConnection() throws SQLException {
         return ds.getConnection();

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

@@ -16,12 +16,15 @@ public class Employee {
     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;
     }
@@ -29,44 +32,54 @@ public class Employee {
     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 + "]";
+        return String.format("Employee [empNo=%d, ename=%s, job=%s, mgr=%d, hiredate=%s, sal=%d, comm=%d, deptno=%d]", empNo, ename, job, mgr, hiredate, sal, comm, deptno);
     }
 
 }

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

@@ -9,13 +9,11 @@ import java.util.List;
 
 public class HikariCPDemo {
 
-	public static List<Employee> fetchData() {
+    public static List<Employee> fetchData() throws SQLException {
         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>();
+        List<Employee> employees;
+        try (Connection con = DataSource.getConnection(); PreparedStatement pst = con.prepareStatement(SQL_QUERY); ResultSet rs = pst.executeQuery()) {
+            employees = new ArrayList<>();
             Employee employee;
             while (rs.next()) {
                 employee = new Employee();
@@ -29,8 +27,6 @@ public class HikariCPDemo {
                 employee.setDeptno(rs.getInt("deptno"));
                 employees.add(employee);
             }
-		} catch (SQLException e) {
-			e.printStackTrace();
         }
         return employees;
     }