Hibernate Access field




By using access field , there is no need to create getter/setter methods in the POJO file.
There are three values for access attribute
(a) field
(b) property   (default)
(c) ClassName

However this attribute is optional but its default value is property.
It can be specified  at any of the following point
(a) Hibernate-mapping node of hbm file 
 or
(b) in each id and property node of class node in the hbm file.










But if we dont create getter/setter methods for attibute and we have also not given access attribute in hbm file and we have also mentioned its mapping in hbm file then hibernate will throw exception

org.hibernate.PropertyNotFoundException: Could not find a getter for firstName in class accesstest.Person





1. Create POJO File


package accesstest;

public class Person {
      private int id;
      String firstName;
      String lastName;
   
      /*
    public String getFirstName() {
        return firstName;
    }
   
    public String getLastName() {
        return lastName;
    }
   
   
     public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
     */
   
}






2. Create any of the following hbm files by name "Person.hbm.xml".

<?xml version="1.0"?>

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<!-- Generated Dec 21, 2012 7:12:56 PM by Hibernate Tools 3.4.0.CR1 -->

<hibernate-mapping>

    <class name="accesstest.Person" table="Person" >

        <id name="id" type="int" access="field">

            <column name="ID" />

            <generator class="increment" />

        </id>

        <property name="firstName" type="java.lang.String" access="field">

            <column name="FIRSTNAME" />

        </property>

        <property name="lastName" type="java.lang.String" access="field">

            <column name="LASTNAME" />

        </property>

    </class>

</hibernate-mapping> 

OR

<?xml version="1.0"?>

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<!-- Generated Dec 21, 2012 7:12:56 PM by Hibernate Tools 3.4.0.CR1 -->

<hibernate-mapping default-access="field">

    <class name="accesstest.Person" table="Person">

        <id name="id" type="int" >

            <column name="ID" />

            <generator class="increment" />

        </id>

        <property name="firstName" type="java.lang.String" >

            <column name="FIRSTNAME" />

        </property>

        <property name="lastName" type="java.lang.String" >

            <column name="LASTNAME" />

        </property>

    </class>

</hibernate-mapping>

3.  Create main method


package accesstest;

import java.util.*;
import org.hibernate.*;
import org.hibernate.cfg.*;


public class Main {

   
    public static void main(String args[]){



        try
        {
        SessionFactory factory = new Configuration().configure("a.cfg.xml").buildSessionFactory();
        Session session = factory.openSession();

        Transaction t = session.beginTransaction();
       

        Person p = new Person();
        p.firstName = "PRASHANT 3";
        p.lastName =" Lal 3";
      
         //p.setFirstName("prashant");
        //p.setLastName("lal");
       
       
       
       
        session.saveOrUpdate(p);
        session.flush();
        t.commit();


        session.close();
        }
        catch(Exception e)
        {
        e.printStackTrace();   
        }   
    }
}






4. Create hibernate configuration file

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"
                                         "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
 <session-factory>
  <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
  <property name="hibernate.connection.url">jdbc:mysql://localhost/test</property>
  <property name="hibernate.connection.username">root</property>
  <property name="hibernate.connection.password">root</property>
  <property name="hibernate.connection.pool-size">10</property>
  <property name="show_sql">true</property>
  <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
  <property name="hibernate.query.factory_class">org.hibernate.hql.classic.ClassicQueryTranslatorFactory</property>
 
  <mapping resource="accesstest/Person.hbm.xml"/>
 
 </session-factory>
</hibernate-configuration>


5. Run the Main.java file


Hibernate Output

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.Configuration addResource

INFO: Reading mappings from resource : accesstest/P.hbm.xml

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.HbmBinder bindRootPersistentClassCommonValues

INFO: Mapping class: accesstest.P -> P

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.Configuration doConfigure

INFO: Configured SessionFactory: null

Dec 21, 2012 8:16:36 PM org.hibernate.connection.DriverManagerConnectionProvider configure

INFO: Using Hibernate built-in connection pool (not for production use!)

Dec 21, 2012 8:16:36 PM org.hibernate.connection.DriverManagerConnectionProvider configure

INFO: Hibernate connection pool size: 20

Dec 21, 2012 8:16:36 PM org.hibernate.connection.DriverManagerConnectionProvider configure

INFO: autocommit mode: false

Dec 21, 2012 8:16:36 PM org.hibernate.connection.DriverManagerConnectionProvider configure

INFO: using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql://localhost/test

Dec 21, 2012 8:16:36 PM org.hibernate.connection.DriverManagerConnectionProvider configure

INFO: connection properties: {pool-size=10, user=root, password=****}

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: RDBMS: MySQL, version: 5.5.22

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: JDBC driver: MySQL-AB JDBC Driver, version: mysql-connector-java-3.0.15-ga ( $Date: 2004/08/09 22:15:11 $, $Revision: 1.27.2.43 $ )

Dec 21, 2012 8:16:36 PM org.hibernate.dialect.Dialect <init>

INFO: Using dialect: org.hibernate.dialect.MySQLDialect

Dec 21, 2012 8:16:36 PM org.hibernate.transaction.TransactionFactoryFactory buildTransactionFactory

INFO: Using default transaction strategy (direct JDBC transactions)

Dec 21, 2012 8:16:36 PM org.hibernate.transaction.TransactionManagerLookupFactory getTransactionManagerLookup

INFO: No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recommended)

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Automatic flush during beforeCompletion(): disabled

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Automatic session close at end of transaction: disabled

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: JDBC batch size: 15

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: JDBC batch updates for versioned data: disabled

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Scrollable result sets: enabled

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: JDBC3 getGeneratedKeys(): enabled

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Connection release mode: auto

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Maximum outer join fetch depth: 2

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Default batch fetch size: 1

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Generate SQL with comments: disabled

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Order SQL updates by primary key: disabled

Dec 21, 2012 8:16:36 PM org.hibernate.cfg.SettingsFactory createQueryTranslatorFactory

INFO: Query translator: org.hibernate.hql.classic.ClassicQueryTranslatorFactory

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Query language substitutions: {}

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: JPA-QL strict compliance: disabled

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Second-level cache: enabled

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Query cache: disabled

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory createCacheProvider

INFO: Cache provider: org.hibernate.cache.NoCacheProvider

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Optimize cache for minimal puts: disabled

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Structured second-level cache entries: disabled

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Echoing all SQL to stdout

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Statistics: disabled

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Deleted entity synthetic identifier rollback: disabled

Dec 21, 2012 8:16:37 PM org.hibernate.cfg.SettingsFactory buildSettings

INFO: Default entity-mode: pojo

Dec 21, 2012 8:16:37 PM org.hibernate.impl.SessionFactoryImpl <init>

INFO: building session factory

Dec 21, 2012 8:16:37 PM org.hibernate.tuple.PojoInstantiator <init>

INFO: no default (no-argument) constructor for class: inheritancesub.PersonEmployee (class must be instantiated by Interceptor)

Dec 21, 2012 8:16:37 PM org.hibernate.tuple.PojoInstantiator <init>

INFO: no default (no-argument) constructor for class: inheritancesub.Person (class must be instantiated by Interceptor)

Dec 21, 2012 8:16:37 PM org.hibernate.tuple.PojoInstantiator <init>

INFO: no default (no-argument) constructor for class: inheritancesub.Personowner (class must be instantiated by Interceptor)

Dec 21, 2012 8:16:37 PM org.hibernate.impl.SessionFactoryObjectFactory addInstance

INFO: Not binding factory to JNDI, no JNDI name configured

Hibernate: select max(ID) from P

Hibernate: insert into P (FIRSTNAME, LASTNAME, ID) values (?, ?, ?)

Oracle Converting delimited string to column

WITH
test AS
( select
column_value AS c1
FROM
TABLE( SYS.DBMS_DEBUG_VC2COLL( 'CAT','DOG','MOUSE' , 'RAT' , 'BAT' , 'CAR' , 'DOOR' , 'LOCK') )
)
SELECT * FROM test ;



Output will like following

C1
CAT
DOG
MOUSE
RAT
BAT
CAR
DOOR
LOCK

Oracle getting nth string from comma separated string

For example getting 2nd string from 'CAT,DOG,MOUSE,RAT,BAT,CAR,DOOR,LOCK'  will be DOG

SELECT REGEXP_SUBSTR(MYCOL, '[^,]+', 1, 2) AS VAL
FROM
(
   SELECT 'CAT,DOG,MOUSE,RAT,BAT,CAR,DOOR,LOCK' AS MYCOL FROM DUAL
);

Oracle Comma to Row conversion

SELECT substr(str, instr(str, ',', 1, LEVEL) + 1, instr(str, ',', 1, LEVEL + 1) - instr(str, ',', 1, LEVEL) - 1) column_value
FROM   (SELECT ',' || 'first,second,third,fourth,fifth,sixth' || ',' str FROM dual)
CONNECT BY LEVEL <= length(str) - length(REPLACE(str, ',')) - 1;


Just replace your comma separated string 'first,second,third,fourth,fifth,sixth'  with your comma separated words.


You can also use the same query for retrieving the output , put the same query in the inner query and fetch the output

SELECT * FROM  mstlocations WHERE mstloc_pincode IN
 (
SELECT substr(str, instr(str, ',', 1, LEVEL) + 1, instr(str, ',', 1, LEVEL + 1) - instr(str, ',', 1, LEVEL) - 1) column_value
FROM   (SELECT ',' || '411038,411028' || ',' str FROM dual)
CONNECT BY LEVEL <= length(str) - length(REPLACE(str, ',')) - 1
);

The above query can be written by using LIKE operator but the performance will be little bit slow if records are huge.

 JAVA COLLECTION

The Java Collections API's provide Java developers with a set of classes and interfaces that makes it easier to handle collections of objects. In a sense Collection's works a bit like arrays, except their size can change dynamically, and they have more advanced behaviour than arrays.

Most of the Java collections are located in the java.util package. Java also has a set of concurrent collections in the java.util.concurrent package

Java Collections
Java Collections Introduction Overview of Interfaces     Iterable    Collection     Generic Collections         List    Set SortedSet    NavigableSet    Map    SortedMap NavigableMap     Queue     Deque    Stack         hashCode() and equals()     Sorting