Configure Hibernate Application to use multiple database

Hi folks,

                In last couple of weeks, My team was working on configuring our application's Hibernate layer to use multiple database schema. Following are the steps we followed:

1.  created hibernate.properties and hibernate.cfg.xml  for every database schema with different name eg. for schema zMRDB, we have created hibernatezMRDB.properties and hibernatezMRDB.cfg.xml files.
2. don't use hibernate.properties and hibernate.cfg.xml  default files for any schema
3. Finally at the time of Session Factory creation use following code

public static SessionFactory getSessionFactory() {
     if (sessionFactory == null) {
   try {
    final Configuration cfg = new Configuration();
    Properties connectionProperties = new Properties();
    InputStream inStream = ThreadLocalUtil.class.getClassLoader().getResourceAsStream("hibernatezMRDB.properties");
    connectionProperties.load(inStream);
    cfg.setProperties(connectionProperties);
    sessionFactory = cfg.configure("hibernatezMRDB.cfg.xml").buildSessionFactory();
    
   
   } catch (Throwable ex) {
    ex.printStackTrace();
   }
  }
  return sessionFactory;
    } 

4. Use SessionFactory returned by method in STEP 3 to open and use session with specific Database.

Easy Way to iterate Over Map

public void displayMapContaint(Map<String, String> data) {
  for (Map.Entry<String, String> pair : data.entrySet()) {
   System.out.println("Key: " + pair.getKey() + " Data: "+ pair.getValue());
  }
 }

Utility class to findout Message Digest checksum for downloded file.

hi,

lot of time after downloading/uploading some file we required some utility to verify integrity of file. This class will be useful for that times. You can generate Message Digest checksum for different algorithem. eg. MD5,SHA1 etc.

package com.blogspot.pravingole;


import java.io.FileInputStream;
import java.security.MessageDigest;
 
public class TestCheckSum {
 
  public static void main(String args[]) throws Exception {
 
    String datafile = "D:/baretailpro.exe"; 
 /*
  * Supported Algorithms are 
  * 
  * MD2,MD5,SHA1,SHA256,SHA384,SHA512
  * 
  */
    MessageDigest md = MessageDigest.getInstance("SHA1");
    FileInputStream fis = new FileInputStream(datafile);
    byte[] dataBytes = new byte[1024];
 
    int nread = 0; 
 
    while ((nread = fis.read(dataBytes)) != -1) {
      md.update(dataBytes, 0, nread);
    };
 
    byte[] mdbytes = md.digest();
 
    //convert the byte to hex format
    StringBuffer sb = new StringBuffer("");
    for (int i = 0; i < mdbytes.length; i++) {
     sb.append(Integer.toString((mdbytes[i] & 0xff) + 0x100, 16).substring(1));
    }
 
    System.out.println("Digest(in hex format):: " + sb.toString());
 
  }
}