Republished articles with source attribution. This collection is separate from Diary Coding’s original guides and does not display ads.
In this example you’ll see how to create a simple port scanner program to check the open ports for the specified host name. package org.kodejava.net; import java.io.IOException; import java.net.InetAddress; import java.net.Socket; public class PortScanner { public static void main(String[] args) throws Exception { String host = "localhost"; InetAddress inetAddress = InetAddress.getByName(host); String hostName = inetAddress.getHostName(); […]
This example shows you how to get the maximum number of concurrent connections to a database that are possible. To get this information, we use the DatabaseMetaData.getMaxConnections() method call. If the return value is zero, it means that there is no limit or the limit is unknown. package org.kodejava.jdbc; import java.sql.Connection; import java.sql.DatabaseMetaData; import java.sql.SQLException; […]
package org.kodejava.jdbc; import java.sql.Driver; import java.sql.DriverManager; import java.sql.SQLException; public class JDBCCompliant { private static final String URL = "jdbc:mysql://localhost/kodejava"; public static void main(String[] args) { try { Driver driver = DriverManager.getDriver(URL); // Check if the driver is a genuine JDBC compliant driver. if (driver.jdbcCompliant()) { System.out.println("A genuine JDBC compliant driver"); } else { System.out.println("Not...
The example below shows you how to get the information about the possible properties for the corresponding JDBC driver. package org.kodejava.jdbc; import java.sql.*; public class DriverPropertyInfoDemo { private static final String URL = "jdbc:mysql://localhost/kodejava"; public static void main(String[] args) { try { // Gets information about the possible properties for this // driver. Driver driver […]
This example show you how to use the CallableStatement.wasNull() method call to see if the last OUT parameter has a value of SQL NULL. package org.kodejava.jdbc; import java.math.BigDecimal; import java.sql.Connection; import java.sql.CallableStatement; import java.sql.DriverManager; import java.sql.Types; import java.sql.SQLException; public class WasNullExample { private static final String URL = "jdbc:mysql://localhost/kodejava"; private static final String USERNAME = […]
To convert double value into an int value we can use type casting or using the Double.intValue() method call. The code snippet below show you how to do it. package org.kodejava.basic; public class DoubleToInt { public static void main(String[] args) { Double numberA = 49.99; System.out.println("numberA = " + numberA); // Converting Double value to […]
Stay curious. There is always something new to learn.
Writer and founder of Diary Coding — sharing notes, tutorials, and experiences about programming for anyone who wants to keep learning.