How to upload text files into MaxDB Database instances using Java? - Part 2

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How to upload text files into MaxDB Database instances using Java? - Part 2

In my previous blog How to upload text files into MaxDB Database instances using Java? - Part 1 the simple steps to upload a text file to MaxDB Database server was discussed. In this weblog the remaining half of the operations such as download and modify have been discussed.

Downloading files from MaxDB Database

Then a java program that performs the file download is given below. The file names have been hard coded here for testing purpose. You can modify them as per your need.

JDBC Program to download file

/* * DownloadFileFromMaxDB.java * * Created on June 15, 2005, 5:46 PM * * Programmed By : Kathirvel Balakrishnan * Designation   : Technical Consultant * Vertical      : Enterprise Application Solutions - SAP * Company       : Wipro Technologies * Email Id      : kathirvel.balakrishnan@wipro.com */package com.myimageprogram;import java.io.*;import java.sql.*;import java.util.*;public class DownloadFileFromMaxDB {        String ImgFile = "d:/maxdbdata.txt";        /** Creates a new instance of InsertImage */    public DownloadFileFromMaxDB() {    }        public void downloadFile() throws Exception {                System.out.println("Before DataBase Connection ");               try {                         // All database access is within a try/catch block. Connect to database,  // specifying particular database, username, and password  // required connection parameters  String  Server = "localhost",Database="TEST",User="DBADMIN",Password="maxdb";          // get connection  Connection con = DriverManager.getConnection ("jdbc:sapdb://" + Server + "/" +  Database, User, Password);    // Create and execute an SQL Statement  Statement stmt = con.createStatement(  );  System.out.println("The con value is:" + con);  ResultSet rs = null;  rs =  stmt.executeQuery("SELECT * FROM addimage where imgid = '1'");  // Display the SQL Results  while(rs.next(  ))   {   System.out.println(rs.getString (1) +"     "+ rs.getString(2));                        System.out.println("Downloading the data file"+ImgFile);                        byte[] file=rs.getBytes(3);                        FileOutputStream fos=new FileOutputStream(new File(ImgFile));                        fos.write(file);  }   // Make sure our database resources are released  rs.close(  );  stmt.close(  );  con.close(  );                       } catch(Exception e) {            // Prints if any exception is raised            System.out.println(" Problem : "+e);        }    }        public static void main(String args[]) throws Exception {        try {            // This is where we load the driver            Class.forName("com.sap.dbtech.jdbc.DriverSapDB");            System.out.println("The Driver has been loaded");        } catch (ClassNotFoundException e) {            // Prints if any exception is raised            System.out.println("Unable to load Driver Class");            return;        }                DownloadFileFromMaxDB Img = new DownloadFileFromMaxDB();                // Calling the add image method        Img.downloadFile();    }}

Executing Queries and Result

Checking the downloaded

A simple check for the downloaded file.

Modifying the file contents in MaxDB Database

The modification of the data can be performed using the below given program.

JDBC Program to modify file

/* * ModifyFilesInMaxDB.java * * Created on June 19, 2005, 9:35 AM * * Programmed By : Kathirvel Balakrishnan * Designation   : Technical Consultant * Vertical      : Enterprise Application Solutions - SAP * Company       : Wipro Technologies * Email Id      : kathirvel.balakrishnan@wipro.com */package com.myimageprogram;import java.io.*;import java.sql.*;import java.util.*;public class ModifyFilesInMaxDB {        byte[] file = new byte[1449616];        String filedata= "File Updated through java: Old Values replaced with new data";          /** Creates a new instance of ModifyFilesInMaxDB */    public ModifyFilesInMaxDB() {    }        public void modifyFile() throws Exception {                System.out.println("Before DataBase Connection ");               try {            // Declaring the connection parameters            String  Server = "localhost",Database="TEST",User="DBADMIN",Password="maxdb";            PreparedStatement pst = null;            // Establishing a connection             Connection con = DriverManager.getConnection("jdbc:sapdb://" + Server + "/" +  Database, User, Password);              // Create and execute an SQL Statement  Statement stmt = con.createStatement(  );  System.out.println("The con value is:" + con);                //Updating the file contents                System.out.println("Modifying the file contents");                pst = con.prepareStatement("update addimage set image = ? where imgid = '1'");                pst.setBytes(1, filedata.getBytes());                pst.executeUpdate();                        // Closing the connection parameters            con.close();            pst.close();        } catch(Exception e) {            // Prints if any exception is raised            System.out.println(" Problem : "+e);        }    }        public static void main(String args[]) throws Exception {        try {            // This is where we load the driver            Class.forName("com.sap.dbtech.jdbc.DriverSapDB");            System.out.println("The Driver has been loaded");        } catch (ClassNotFoundException e) {            // Prints if any exception is raised            System.out.println("Unable to load Driver Class");            return;        }                ModifyFilesInMaxDB Img = new ModifyFilesInMaxDB();                // Calling the modify method        Img.modifyFile();    }    }

Executing Queries and Result

Checking the modified values by downloading the file

A simple check by the downloading the file.



This is a very simple weblog. Hope this was useful to you.