JCR 1.0 defines a standard Java API for applications to interact with content repositories. A content repository is a tree of nodes, each of which can have one or more child nodes. Each node has exactly one parent node, except for the root node, which has no parent.

In addition to child nodes, a node may also have one or more properties. A property is a simple name/value pair. For example, a node representing a particular file in the content repository has a property named jcr:created whose value is the date the file was created.

Each property has a property type. For example, the jcr:created property has the DATE property type, requiring its value to be a valid date/time.

Similarly, each node has a node type. For example, a node representing a file has node type nt:file. The node type controls what child nodes and properties the node may have or must have. For example, all nodes of type nt:file must have a jcr:created property.

Because nodes and properties are named, they can be addressed by path. JCR supports both absolute and relative paths. For example, the absolute path

/My Documents/pictures/puppy.jpg/jcr:created

resolves to the jcr:created property of file puppy.jpg. This property can also be addressed relative to the My Documents folder by the following relative path:

pictures/puppy.jpg/jcr:created

Node and property names can be namespace qualified. Like XML, JCR uses colon-delimited namespace prefixes to express namespace-qualified names, for example, jcr:created. Unlike XML, JCR records the namespace prefix-to-URI mappings in a repository-wide namespace registry, which, for example, maps the jcr prefix to the URI http://www.jcp.org/jcr/1.0.

Oracle XML DB Content Connector lets you access Oracle XML DB Repository using JCR 1.0 Java. Your applications can run either in a standalone Java Virtual Machine (JVM) or a J2EE container. Files and folders in the repository are represented as JCR nodes (and properties of those nodes).

You can create, retrieve, and update repository files and folders using the JCR APIs.

Oracle XML DB Content Connector represents data in Oracle XML DB Repository as JCR nodes and properties. Files and folders are represented as nodes of type nt:file and nt:folder, respectively. Their content and metadata is exposed as nodes of node type nt:resource.

Oracle XML DB Content Connector requires certain entries in environment variable CLASSPATH.

• $ORACLE_HOME/lib/jcr-1.0.jar

• $ORACLE_HOME/lib/ojcr.jar

• $ORACLE_HOME/lib/xmlparserv2.jar

• $ORACLE_HOME/jlib/xquery.jar

In Oracle XML DB Content Connector, oracle.jcr.OracleRepository implements JCR interface javax.jcr.Repository, which provides the entry point for a JCR repository. You can use it to obtain a Repository object for Oracle XML DB Repository.

import oracle.jcr.OracleRepository;
import oracle.jcr.OracleRepositoryFactory;
import oracle.jcr.xdb.XDBRepositoryConfiguration;
import oracle.jdbc.pool.OracleDataSource;
...
XDBRepositoryConfiguration configuration =
  new XDBRepositoryConfiguration();
OracleDataSource ods =
  (OracleDataSource)configuration.getDataSource();
// databaseURL is a JDBC database URL.
ods.setURL(databaseURL);
// OracleRepository implements javax.jcr.Repository.
OracleRepository repository =
  OracleRepositoryFactory.createOracleRepository(configuration);

You can use Oracle XML DB Content Connector to upload a file from the local file system to Oracle XML DB Repository.

import java.io.FileInputStream;
 
import javax.jcr.Node;
import javax.jcr.Session;
import javax.jcr.SimpleCredentials;
 
import oracle.jcr.OracleRepository;
import oracle.jcr.OracleRepositoryFactory;
 
import oracle.jcr.xdb.XDBRepositoryConfiguration;
 
import oracle.jdbc.pool.OracleDataSource;
 
public class UploadFile
{
  public static void main(String[] args)
    throws Exception
  {
    String databaseURL = args[0];
    String userName = args[1];
    String password = args[2];
    String parentPath = args[3];
    String fileName = args[4];
    String mimeType = args[5];
    
    // Get the JCR Repository object.
    XDBRepositoryConfiguration configuration =
      new XDBRepositoryConfiguration();
 
    OracleDataSource ods =
      (OracleDataSource)configuration.getDataSource();
 
    ods.setURL(databaseURL);
    
    OracleRepository repository =
      OracleRepositoryFactory.createOracleRepository(configuration);
    
    // Create a JCR Session.
    SimpleCredentials sc =  
      new SimpleCredentials(userName, password.toCharArray());
 
    Session session = repository.login(sc);
 
    // Get the parent node.
    Node parentNode = (Node)session.getItem(parentPath);
    
    // Get the child contents.
    FileInputStream inputStream = new FileInputStream(fileName);
    
    // Create child node.
    Node node = parentNode.addNode(fileName, "nt:file");
    Node contentNode = node.getNode("jcr:content");
    contentNode.setProperty("jcr:mimeType", mimeType);
    contentNode.setProperty("jcr:data", inputStream);
    
    // Save changes and logout.
    session.save();
    session.logout();
  }
}
 
// EOF

export CLASSPATH=.:$ORACLE_HOME/lib/jcr-1.0.jar:$ORACLE_HOME/lib/ojcr.jar:Foot 1
$ORACLE_HOME/lib/xmlparserv2.jar:$ORACLE_HOME/jlib/xquery.jar

javac UploadFile.java
java UploadFile jdbc:oracle:oci:@ quine password /public MyFile.txt text/plain

You can find additional sample JCR code at $ORACLE_HOME/xdk/demo/java/jcr. For each code sample, a README file describes its purpose and use.

Oracle XML DB Content Connector uses the standard java.util.logging framework. You can use the logging API provided by that framework to control logging behavior.

For example, the following Java code fragment disables all logging.

import java.util.logging.LogManager;
...
LogManager.getLogManager().reset();

The JSR-170 standard, which defines JCR version 1.0, defines two compliance levels and a set of optional features. Oracle XML DB Content Connector supports Level 1 (read functions) and Level 2 (write functions).

Certain restrictions apply to Oracle XML DB Content Connector.

Oracle XML DB Content Connector can create JCR node types from XML schemas.