Java and Derby integration using JDBC (using NetBeans)

Before writing a Java class to use JDBC,

-Check the JDK version -Set environment variables (so that the Java app can recognize the JDBC driver) 　　https://www.agtech.co.jp/html/v11manuals/11.20/jdbc/jdbc-2-2.html　 (Click here for the information) 　　https://netbeans.org/competition/win-with-netbeans/mysql-client_ja.html (For NetBeans) -Check the appropriate setting method for JDBC driver, etc. 　　http://www.ne.jp/asahi/hishidama/home/tech/java/javadb.html ・ If you search for Derby JDBC, you will find a powerful site. -The user ID and password of the Derby database must be set to "APP".

How to write Java class to use JDBC (example)

The following is an example of outputting data from the database. The following outputs data from a database that has a table like Table 1.

Table 1 EMPLOYEES

Example 1 Writing a JDBCcon class

import java.sql.*;
　public class JDBCcon {
   　 public static void main (String[] args){      
        Statement stmt = null;
        ResultSet rs = null;
        Connection con = null;
        
        try{
        //Step 1 Driver registration
        Class.forName("org.apache.derby.jdbc.ClientDriver");

         
        //Step 2 Designate the database
        String url = "jdbc:derby://localhost:1527/EmployeeDB";
        
        //Step 3 Establish a connection to the database
        con = DriverManager.getConnection(url,"APP","APP");
        
        //Step 4 Create a statement
        stmt = con.createStatement();
        
        //Step 5:SQL execution
        String sql ="SELECT * FROM EMPLOYEES";
         
        rs = stmt.executeQuery(sql);
        
        //Step 6:Processing results
          while (rs.next()){
            System.out.println("EMP_NO = " + rs.getString(1));
            System.out.println("EMP_NAME = " + rs.getString(2));
            System.out.println();
          }
        
        } catch(ClassNotFoundException e){
          System.out.println(e.getMessage());
          e.printStackTrace();
        } catch(SQLException e){
          System.out.println(e.getMessage());
          e.printStackTrace();
          
        //Step 7:Exit JDBC object
        } finally{
          try{
            if(rs != null) rs.close();
            if(stmt != null) stmt.close();
            if(con != null) con.close();
          }catch (SQLException e){}
        }    
    }
}

Example 2 Execution result

run:
EMP_NO = 1
EMP_NAME = HOGE      

EMP_NO = 2
EMP_NAME = HORII     

Postscript: From JDBC 4.0 of JDK 1.6, it seems to automatically load the driver in the classpath. Thank you for pointing out.