ExistClient
Introduction
The ExistClient is a Java library that implements the ISClient interface provided by the gCoreFramework. This library allow the developer to execute queries on the Information System.
Implementation Overview
The ExistClient implements all the query defined in the ISClient Interface:
Queries over GCUBEResource:
- GCUBECollectionQuery
- GCUBECSInstanceQuery
- GCUBECSQuery
- GCUBEExternalRIQuery
- GCUBEGenericResourceQuery
- GCUBEGHNQuery
- GCUBEMCollectionQuery
- GCUBERIQuery
- GCUBEServiceQuery
- GCUBETPQuery
- GCUBEVREQuery
Queries over GCUBEWSResource:
- WSResourceQuery
The ExistClient also offers the possibility to execute custom queries: GCUBEGenericQuery. GCUBEGenericQuery allows the developer to set the query expression to execute or to use a predefined set of queries which he should set some parameters on:
- GCUBEResourceQuery
- GCUBEWSResourceQuery
- RIEndpoint
- RIOnGHN
- RISpecificData
- GHNIDFromHostName
- InternalCollections
- UserCollectionIDsFromSchemaURI
- MCollectionIDForCollection
- MCollectionFormatsForCollection
- MCollectionIDFromCollectionIDAndRole
- MCollectionIDFromFormatLanguage
- MCollectionIDFromFormatLanguage
- MCollectionIDFromName
- MCollectionIDFromSchemaURI
Usage Examples
The ISclient reference implementation makes use of Xquery Technology to query over the underneath Exist database. Client/services can prepare a custom xQuery over the DB and use the Generic Query object to excecute it and going through the result with an XPath:
GCUBEGenericQuery query = client.getQuery(GCUBEGenericQuery.class);
query.setExpression("for $Profile in collection(\"/db/Profiles\")//Document/Data/child::*[local-name()='Profile']/Resource return $Profile/UniqueID");
List<XMLResult> result =client.execute(query, scope);
for (String resultItem :result ) {
System.out.println(resultItem.evaluate("an XPath ... "));
System.out.println(resultItem.toString());
}
You can use a predefined ISQuery Object as well:
GCUBEWSResourceEPRFromRPValuesAndNamespaceQuery query = client.getQuery(GCUBEWSResourceEPRFromRPValuesAndNamespaceQuery.class);
GCUBEWSProperty property = new GCUBEWSProperty("IndexTypeName","index_type_string_string");
GCUBEWSProperty property2 = new GCUBEWSProperty("IndexID","999ba610-e9fb-11dc-b51b-84732c1e88f2");
ArrayList <GCUBEWSProperty> properties = new ArrayList();
properties.add(property);
properties.add(property2);
query.setPropertiesValuesAndNamespace(properties, "http://gcube-system.org/namespaces/index/ForwardIndexManagementService");
List<EndpointReferenceType> result = client.execute(query, scope);
for (EndpointReferenceType resultItem :result ) {
System.out.println(resultItem.toString());
}
