For our internal search engine I am currently developing a simple microservice to make our CMDBuild instance searchable. The microservice provides a fairly simple JSON API which itself queries the REST API of CMDBuild. Because of the insufficient documentation of CMDBuild I had to dig into the the source how to write a wildcard search query. CMDBuild has its own query language called CQL (CMDBuild Query Language). The CQL statements are converted into SQL which can be executed natively by PostgreSQL. CQL does also allow to include native SQL statements into the CQL queries. Native SQL statements are masked with (/( … )/). Between us, the combination CQL and SQL produces a absolute messy code, but this another story.
One problem is, that the REST search API of CMDBuild is exposed through HTTP GET. Accessing the HTTP endpoint with a filter like
GET https://cmdbuild/services/rest/v2/cql?filter={CQL: "from Department where Description (/(LIKE 'Develop%')/)"}
does unfortunately confuse the Apache CXF interceptor which struggles upon the percent sign. Encoding the percent does not help and a POST request is not allowed.
To fix this problem I took a look into the source of CMDBuild. Luckily for me the CQL parser is automatically generated with help of ANTLR. The grammer file is much better than any incomplete example from the official forum. So I discovered that CQL natively provides the following operators: CONTAINS, BEGIN, END, BETWEEN, NULL.
In the end it worked as I had expected:
GET https://cmdbuild/services/rest/v2/cql?filter={CQL: "from Department where Description CONTAINS 'Develop'"}
