JDBC / NOTES</>↗JDBC18 Feb 2007
In this example we’ll show how to use ResultSetMetaData.isNullable() method to know if a column can be null or not. This method returns an integer which values defined in the constants of ResultSetMetaData.columnNullable, ResultSetMetaData.columnNoNulls and ResultSetMetaData.columnNullableUnknown. package org.kodejava.jdbc; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; imp...
JDBC / NOTES</>↗JDBC13 Feb 2007
The ResultSetMetaData.isAutoIncrement() method can tell us if a column value is automatically numbered or not. This method return true when the column is an auto-increment column, otherwise it returns false. See the example below where we check if the first column (id) is an auto-increment column. package org.kodejava.jdbc; import java.sql.*; public class IsAutoIncrementExample { private […]
JDBC / NOTES</>↗JDBC13 Feb 2007
This example show how we can use the ResultSetMetadata class to get the number of columns and column names of the selected table. The ResultSetMetaData class can also be used to get the column type and its properties. Using the ResultSetMetaData class might help you to create an inquiry program where you don’t have all […]
SERVLET / NOTES</>↗Servlet10 Feb 2007
package org.kodejava.servlet; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; @WebServlet(name = "ResponseStatusServlet", urlPatterns = "/response-status") public class ResponseStatus extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse...
SERVLET / NOTES</>↗Servlet07 Feb 2007
When creating a servlet we can use the @WebInitParam to define some init parameters in the servlet configuration section (@WebServlet). This init parameter can be used to define where a configuration file of our application is stored, define upload path, etc. This simple servlet below shows how to obtain these init parameters value. package org.kodejava.servlet; […]
SERVLET / NOTES</>↗Servlet04 Feb 2007
package org.kodejava.servlet; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; @WebServlet(name = "ReadCookieServlet", urlPatterns = "/read-cookie") public class ReadCookieExample extends HttpServlet { @Override protected vo...
