Load() can’t find the object from cache or database, an exception is thrown and the load() method never returns null. If the identifier exists, it will call update method. If the identifier is missing this method calls save(). Saveorupdate () -This method in the hibernate is used for updating the object using identifier. It insert an entry if the record doesn’t exist, otherwise not. Save() – This method in hibernate is used to stores an object into the database. It works by transforming the data from one representation to another. The objects in a Java class which is mapped in to the tables of a relational database using the metadata that describes the mapping between the objects and the database. ORM stands for Object-Relational mapping. Mapping of Domain object to relational database. Hibernate is portable i mean database independent, Vendor independence. Only query language support for composite keys. Slower in executing the queries than queries are used directly. Hibernate also allows you to express queries using java-based criteria. It is a beautiful approach for persisting into database using the java objects. Hibernate has more powerful association, inheritance, polymorphism, composition, and collections. In hibernate we can write HQL instead of SQL which save developers to spend more time on writing the native SQL. Hibernate is a open source object-relational mapping and query service. It does not allow duplicate values but it allows null values. Hashtable is a collection Synchronozed object. HashTable is just like Hash Map,Collection having key(Unique),value pairs. It automatically saves the form data to server and populates the form date when display at client side. JSF provide a set of reusable UI components, standard for web applications.JSF is based on MVC design pattern. ![]() JavaServer Faces (JSF) is a user interface (UI) designing framework for Java web applications. JSP pages execute as servlets but allow a more natural approach to creating static content. ![]() Servlets are Java programming language that dynamically receive requests and make responses. Java Servlet and Java Server Pages technology components are web components. Wireless clients, based on MIDP technology. Java Web Start-enabled clients, by Java Web Start technology. Servlet and JSP technology are web components. What are the four components of J2EE application? The J2EE platform is consists of a set of services, application programming interfaces (APIs), and protocols. The functionality of J2EE is developing multitier web-based applications.
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