JavaBeat

Introduction I have been developing Java applications for a long time and the major difficulty was the coding part related to database manipulations. Recently I shifted to use Object-Relational Mapping through JPA. I have used TopLink, EclipseLink, and Hibernate. Although I could achieve the functionally I want with ease, the output was slower when compared [...]

Struts 2.0 is one of the popularly used Presentation tier framework for Java web Applications.It is based on the WebWork2 technology.Struts 2.0 framework implements MVC 2 architecture by centralizing the control using a Front Controller strategy. The extensible and flexible nature of Struts 2.0 makes it the favourite choice of Java web developers. The major [...]

Introduction Hibernate is designed to be used with a large set of databases. The details of those databases are configured in an XML file called hibernate.cfg.xml. This configuration files could be given any name and is usually placed in the root of your application class path. There are many configuration parameters available that makes the [...]

JBoss AS 5 DevelopmentThe JBoss Application Server is a Java EE-certified platform for developing and deploying Java Enterprise applications. JBoss Application Server provides the full range of J2EE 1.5 features as well as extended Enterprise services including clustering, caching, and persistence. This book will show Java EE developers how to develop their applications using the JBoss Application Server. It [...]

Spring Persistence with HibernateThis article is sample chapter taken from the book Spring persistence with Hibernate. Hibernate is a popular open-source Java framework. It aims to solve problems associated with persistence in the Java world. Whether you are developing a simple stand-alone application, or a full-blown, server-side Java EE application, you can use and benefit from Hibernate. Although [...]

1) What is Hibernate? Hibernate is a powerful, high performance object/relational persistence and query service. This lets the users to develop persistent classes following object-oriented principles such as association, inheritance, polymorphism, composition, and collections. Hibernate eliminates developers to spend more time on writing the native SQL queries and understand the complete underlying database persistence mechanism. [...]

The following exception is very common if you are the beginner for hibernate. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Exception in thread "main" org.hibernate.hql.ast.QuerySyntaxException: book is not mapped [from book] at org.hibernate.hql.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:158) at org.hibernate.hql.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:87) at org.hibernate.hql.ast.tree.FromClause.addFromElement(FromClause.java:70) at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:255) at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3056) [...]

If the result set is large, then having the entire result set in memory will not be feasible. With large result sets, you cannot afford to have them in memory. In such case, you have to fetch a chunk of data at a time (query based paging). The down side of using query based paging, [...]

This example program demonstrates how to write the many-to-one accociations using the hibernate mapping files. Book.java 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 package hibernate;   import java.io.Serializable;   public class Book implements Serializable{ [...]

Difference between hibernate’s save,update and saveOrUpdate() methods Hibetnate has set of methods for saving and updating the values in the database. The methods look like same and difficult to differentiate between them if you are not understanding them clearly. If you understand the hibernate mechanism clearly, it doesn’t execute the SQL statements directly to manipulate [...]