sax2j

Schema Aware XML to JSON translator

sax2j is a tool for converting XML to JSON. It uses the XML Schema for the XML document to guide tricky decisions, such as whether to render a single element as a scalar or an array.

The rules followed by sax2j are documented in the Open Mobile Alliance standard Common definitions for RESTful Network APIs OMA-TS-REST_NetAPI_Common-V1_0-20150108-D.

Building

To build sax2j, you need ant (tested with v1.8.1) and Java (tested with 1.7.0_51).

ant build

This will create a runnable JAR file, sax2j.jar.

You can test the code with

ant test

and look at the test report at

testout\index.html

.

Converting XML to JSON

Because the required XML schema support is not built into Java, you must pass special options to Java on startup.

To convert foo.xml to JSON using schema foo.xsd, type:

java -Djava.endorsed.dirs=lib\commons-io-2.4;lib\commons-lang3-3.3.2;lib\xerces-2_11_0-xml-schema-1.1-beta \
     -jar sax2j.jar foo.xml foo.xsd > foo.json

(On Linux, use forward slashes and colons instead of backslashes and semicolons.)

Extracting XML and JSON from Word documents

Many of the Open Mobile Alliance standards contain embedded XML documents and JSON documents which need to be extracted as part of the standards process. The XML documents need to be extracted so that they can be converted, and the JSON documents need to be extracted so that they can be checked (to confirm that they are identical to the result of conversion from XML).

sax2j provides assistance in this process.

This process has been tested with recent OMA ARC standards documents only; with other documents, your mileage may vary.

First, save the document as "Plain Text" in encoding "Unicode (UTF-8)", without inserted linebreaks. E.g. foo.txt.

Then use sax2j to do the conversion as follows:

java -Djava.endorsed.dirs=lib\commons-io-2.4;lib\commons-lang3-3.3.2;lib\xerces-2_11_0-xml-schema-1.1-beta \
     -jar sax2j.jar --extract foo.txt out\foo-fragment

This will scan foo.txt for XML and JSON documents, and write each one to a file foo-fragmentNNNN.xml or foo-fragmentNNN.xml.json in the out directory (which must already exist).

NOTE Currently, only JSON extraction is implemented. OMA ARC has a tool called UNICA XML2JSON Converter for extracting XML, which can be obtained upon request.

Sample data

Some sample data is included in the sample/ directory, from the OMA ARC NMS work.

sax2j --extract sample/OMA-TS-REST_NetAPI_NMS-V1_0-20140715-C.txt sample/data

will extract the contents of the NMS TS into sample/data*.xml.json.

sax2j sample/OMA-SUP-XSD_rest_netapi_nms-V1_0-20140619-D.xsd xmldata_6.11.3.1.2.xml > xmldata_6.11.3.1.2.xml.json

will convert the XML from section 6.11.3.1.2 into JSON, respecting the schema.

(sax2j in the above is an abbreviation for java -Djava.... -jar sax2j.jar as used earlier).

Further sample data can be found in the testdata directories.