Caché and Java Overview
Java Persistence Architecture (JPA) is the recommended persistence technology for complex object hierarchies in Java projects. Caché and Ensemble currently support JPA 1.0 and 2.0 via the Hibernate implementations of the JPA specifications. See “Using the Caché Hibernate Dialect” in Using Caché with JDBC.
Extreme Event Persistence (XEP) is the recommended persistence technology for high-performance simple to medium complexity object hierarchies in Java projects. See “Using XEP Event Persistence” in Using Java with Caché eXTreme.
Caché provides three different approaches to using Java with Caché. After importing your multivalue application to Caché, simply run PROTOCLASS on the application's data dictionaries. The data is then available to Java code through these approaches.
Java Projections – Caché generates Java proxy classes, called Java projections, for Caché classes. Java code can access Caché classes on the Caché server using these projections as intermediaries. This provides an entirely object-oriented approach for exposing a Caché application to Java code. In a typical scenario, the Java code is part of a Java user interface for a Caché application.
Standard JDBC – The Caché JDBC driver provides relational access to Caché data. The JDBC driver is a level 4 (pure Java) driver and supports the JDBC level 3 API.
This section of the tutorial covers only Java Projections and Standard JDBC. These connection options are the most applicable to situations in which you have an existing Caché application that you want to expose to Java, for example, after having imported a MultiValue application to Caché.
For more in depth information on Java projections and JDBC, see the Caché Java Binding and JDBC QuickStart Tutorial as well as Using Java with Caché. The class documentation for the Caché Java binding API is in <cachesys>\Dev\java\doc. In a standard Windows Caché installation, <cachesys> is C:\InterSystems\Cache. In a standard UNIX® installation, <cachesys> is /usr/cachesys.
For instructions on importing a multivalue application to Caché, see Migrating an MultiValue Application. For instructions on using PROTOCLASS, see Running PROTOCLASS.