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The Compact Namespace and Node Type Definition (CND) notation provides a compact standardized syntax for defining node types and making namespace declarations. The notation is intended both for documentation and for programmatically registering node types (if you are unfamiliar with JCR node types, you may want to read the general Node Types section first).

Each node in a Jackrabbit workspace tree has a node type that defines the child nodes and properties it may (or must) have. Developers can use node types to define a custom content model for their application domain and have Jackrabbit enforce the constraints of that model at the repository level.

SymmetricDS is web-enabled, database independent, data synchronization/replication software. It uses web and database technologies to replicate tables between relational databases in near real time. The software was designed to scale for a large number of databases, work across low-bandwidth connections, and withstand periods of network outage. By using database triggers, SymmetricDS guarantees that data changes are captured and atomicity is preserved. Support for database vendors is provided through a Database Dialect layer, with implementations for MySQL, Oracle, SQL Server, PostgreSQL, DB2, Firebird, HSQLDB, H2, and Apache Derby included. Synchronization can be configured to push data (trickle-back) or pull data (trickle-poll) at an interval. SymmetricDS allows for synchronization between two or more tiers of nodes, such as the following: A farm of web server nodes fronting an enterprise-class general office database A handful of regional servers for synchronizing from the general office to remote geographical areas 1000(s) of store server nodes using a departmental class database to sync with a regional node 10(s) of Point of Sale (POS) register nodes using an embedded database to sync with a store server Deployment options include the following: Web application archive (WAR) deployed to an application server such as Tomcat, Jetty, or JBoss Standalone service Embedded in an application SymmetricDS is written in Java and licensed as open source software under the GNU Lesser General Public License (LGPL).

The previous sections have extensively used the CND notation to illustrate the examples. Now that the most important concepts have been demonstrated, this section will give an in-depth overview of the CND. JSR 283 further defines an XML-based format for defining node type definitions, however, it has not been finalized yet at the time of writing. A CND file contains a series of namespace declarations, node type definitions, as well as comments which are denoted with a double slash (//).

Jackson is a: Streaming (reading, writing) FAST (measured to be faster than any other Java json parser and data binder) Powerful (full data binding for common JDK classes as well as any Java bean class, Collection, Map or Enum) Zero-dependency (does not rely on other packages beyond JDK) Open Source (LGPL or AL) Fully conformant Extremely configurable JSON processor (JSON parser + JSON generator) written in Java. Beyond basic JSON reading/writing (parsing, generating), it also offers full node-based Tree Model, as well as full OJM (Object/Json Mapper) data binding functionality.

Apache XML-RPC is a Java implementation of XML-RPC, a popular protocol that uses XML over HTTP to implement remote procedure calls. Version 3 of Apache XML-RPC is still compliant to the XML-RPC specification. However, the user may enable several vendor extensions are available, that greatly extend the power of XML-RPC: All primitive Java types are supported, including long, byte, short, and double. Calendar objects are supported. In particular, timezone settings, and milliseconds may be sent. DOM nodes, or JAXB objects, can be transmitted. So are objects implementing the java.io.Serializable interface. Both server and client can operate in a streaming mode, which preserves resources much better than the default mode, which is based on large internal byte arrays.

JAX-RS 1.1 offers a @ApplicationPath annotation applicable to javax.ws.rs.core.Application which let you specify the webcontext and remove the need for any web.xml