Revision as of 14:54, 8 April 2010

XMLBinaryDataMapping

Requirements

Provide support for XML binary data mapping configuration via XML metadata file.

The following should be configurable:

• Path-based mappings
• Positional mappings
• Read only
• Write only
• Get/set method names

Design

Basic XML binary data mapping support

We will extend our current xml-element and xml-attribute support to allow binary data mapping configuration. For example, the following XML metadata snippet would be used to setup a binary data mapping for 'bytes' (where bytes is a byte[] in the object model):

<xml-attribute java-attribute="bytes" />

The same thing mapped to 'mybytes':

<xml-attribute java-attribute="bytes" xml-path="@mybytes" />

Example:

The following example will demonstrate how to configure XML binary data mappings via XML metadata by using xml-element and xml-attribute.

org.example.MyData.java

package org.example;
 
public class MyData {
    public byte[] bytes;
    public byte[] readOnlyBytes;
    public byte[] writeOnlyBytes;
 
    public byte[] getBytes() {
        return bytes;
    }
 
    public void setBytes(byte[] bytes) {
        this.bytes = bytes;
    }
}

Deployment XML

XML Instance Document (read)

<?xml version="1.0" encoding="UTF-8"?>
<my-data mybytes="AAECAw==" my-read-only-bytes="AQIDBA==">
  <write-only-bytes>AgMEBQ==</write-only-bytes>
</my-data>

XML Instance Document (write)

<?xml version="1.0" encoding="UTF-8"?>
<my-data mybytes="AAECAw==">
  <write-only-bytes>AgMEBQ==</write-only-bytes>
</my-data>

org/example/eclipselink-oxm.xml

This XML file demonstrates configuring XML binary data mappings on the "org.example.MyData" class.

<?xml version="1.0" encoding="US-ASCII"?>
<xml-bindings xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/oxm" xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <java-types>
        <java-type name="org.example.MyData">
            <xml-root-element name="my-data" />
            <java-attributes>
                <xml-attribute java-attribute="bytes" xml-path="@mybytes">
                    <xml-access-methods get-method="getBytes" set-method="setBytes" />
                </xml-attribute>
                <xml-attribute java-attribute="readOnlyBytes" xml-path="@my-read-only-bytes" read-only="true" />
                <xml-element java-attribute="writeOnlyBytes" name="write-only-bytes" write-only="true" />
            </java-attributes>
        </java-type>
    </java-types>
</xml-bindings>

Open Issues

This section lists the open issues that are still pending that must be decided prior to fully implementing this project's requirements.

Decisions

This section lists decisions made. These are intended to document the resolution of open issues or constraints added to the project that are important.