Rest DAO - Learn JBStrap

Fetch

Use this functionality to programmatically retrieve data based on a DataDescriptor from a Rest server. In the data query, you can apply filter criteria to the query (if server side supports it). Filter criteria are JBStrap Criteria objects. Results are returned as DataRecord or List<DataRecord> objects. You can retrieve all the corresponding records or only a subset of the record for a faster response time.

If you specify the client object, the access rights in the DataDescriptor are checked. If a user does not have read rights for the data (as specified in the DataDescriptor), an error is returned, preventing unauthorized access to the data.

Note that by default, the the REST service does not handle filtering by using criteria, ordering, or fetching a new page. If these are not handled, or are only partially handled (only ordering is handled, etc.) the unhandled operations will not function. All of these operations can be implemented in numerous ways. JBStrap allows you to develop your own, custom implementations by using the handler classes.

Here are a few examples of how to fetch data using the Rest DataDescriptor:

  Fetching all data using a DataDescriptor  
        
List<DataRecord> result = RestDaoAPI.find(restDataDescriptor);

  Fetching all data using a DataDescriptor while checking for access rights  
        
List<DataRecord> result = RestDaoAPI.find(restDataDescriptor, client);

  Fetching all data that meet the specified Criteria using a DataDescriptor (fetching every Record object where the first name field is "Evelyn")  
        
List<DataRecord> result = RestDaoAPI.find(restDataDescriptor, new Criteria("firstName", OperatorType.EQUALS, "Evelyn"));

  Fetching the first 50 records using a DataDescriptor that meets the specified filters. If there are more than 50 corresponding records, only the first 50 ones will be fetched).  
        
List<DataRecord> result = RestDaoAPI.find(restDataDescriptor, 0, 50, new Criteria("firstName", OperatorType.EQUALS, "Evelyn");

  Fetching the next 50 records (51-100) while checking the access rights  
        
List<DataRecord> result = RestDaoAPI.find(restDataDescriptor, client, 51, 100, new Criteria("firstName", OperatorType.EQUALS, "Evelyn");

  Fetching the first 50 records that meet the specified criteria and sorting the results in descending order by lastName  
        
List<DataRecord> result = RestDaoAPI.find(restDataDescriptor, client, new Criteria("firstName", OperatorType.EQUALS, "Evelyn"), 
		Arrays.asList(new Order("lastName", OrderType.DESCENDING)), 0, 50);

  Fetching the record where the primary key is 1  
        
DataRecord result = RestDaoAPI.findById(restDataDescriptor, client, 1L);

Counting the records:

  Counting the record rows in a DataDescriptor with filter  
        
long count = RestDaoAPI.getRowCount(restDataDescriptor, client, new Criteria("firstName", OperatorType.EQUALS, "Anne"));

Save and update records:

  Saving records using a DataDescriptor  
        
List<DataRecord> records = ...
List<DataRecord> savedRecords = RestDaoAPI.save(restDataDescriptor, client, records);

Delete records:

  Deleting records using a DataDescriptor  
        
List<DataRecord> deletedRecords = RestDaoAPI.remove(restDataDescriptor, client, records);