Java by API/javax.naming/InitialContext

InitialContext: lookup(String name)

   <source lang="java">

/*

* */

import java.sql.Connection; import javax.naming.InitialContext; import javax.sql.DataSource; public class Main {

 public static void main(String[] args) throws Exception {
   String dsn = args[0];
   System.out.println("Attempting to connect to " + dsn);
   try {
     System.out.println("Initializing the naming context...");
     InitialContext init = new InitialContext();
     System.out.println("Looking up " + dsn);
     DataSource source = (DataSource) init.lookup(dsn);
     System.out.println("Establishing a connection...");
     Connection connection = source.getConnection();
     System.out.println("Connect to " + connection.getCatalog() + " a success!");
   } catch (Exception e) {
     e.printStackTrace();
   }
 }

}

 </source>
   
  
 
  

new InitialContext()

   <source lang="java">

/*

* */

import java.sql.Connection; import javax.naming.InitialContext; import javax.sql.DataSource; public class Main {

 public static void main(String[] args) throws Exception {
   String dsn = args[0];
   System.out.println("Attempting to connect to " + dsn);
   try {
     System.out.println("Initializing the naming context...");
     InitialContext init = new InitialContext();
     System.out.println("Looking up " + dsn);
     DataSource source = (DataSource) init.lookup(dsn);
     System.out.println("Establishing a connection...");
     Connection connection = source.getConnection();
     System.out.println("Connect to " + connection.getCatalog() + " a success!");
   } catch (Exception e) {
     e.printStackTrace();
   }
 }

}

 </source>
   
  
 
  

new InitialContext(Hashtable<?, ?> environment)

   <source lang="java">

import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.Properties; import javax.naming.Context; import javax.naming.InitialContext; import javax.naming.NamingException; import javax.sql.ConnectionPoolDataSource; import javax.sql.PooledConnection; public class Main {

 public static void main(String[] args) throws Exception {
   Connection connection = getConnection();
   // Do work with connection
   Statement statement = connection.createStatement();
   String selectEmployeesSQL = "SELECT * FROM employees";
   ResultSet resultSet = statement.executeQuery(selectEmployeesSQL);
   while (resultSet.next()) {
     printEmployee(resultSet);
   }
   resultSet.close();
   statement.close();
   connection.close();
 }
 private static Connection getConnection() throws NamingException, SQLException {
   InitialContext initCtx = createContext();
   String jndiName = "HrDS";
   ConnectionPoolDataSource dataSource = (ConnectionPoolDataSource) initCtx.lookup(jndiName);
   PooledConnection pooledConnection = dataSource.getPooledConnection();
   return pooledConnection.getConnection(); // Obtain connection from pool
 }
 private static InitialContext createContext() throws NamingException {
   Properties env = new Properties();
   env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.rmi.registry.RegistryContextFactory");
   env.put(Context.PROVIDER_URL, "rmi://localhost:1099");
   InitialContext context = new InitialContext(env);
   return context;
 }
 private static void printEmployee(ResultSet resultSet) throws SQLException {
   System.out.print(resultSet.getInt("employee_id") + ", ");
   System.out.print(resultSet.getString("last_name") + ", ");
   System.out.print(resultSet.getString("first_name") + ", ");
   System.out.println(resultSet.getString("email"));
 }

}

 </source>