You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 3 Next »

Goals

  1. User can specified fields in nested object to be indexed. 

  2. Query on these nested fields as well as top level fields. 

 

Out of Scope

  1. Item in collection will not be index and searched.

 

API

  1. Use fieldnameAtLevel1.fieldnameAtLevel2 to specify a field in nested object both for indexing and querying. 

For example, a Customer object contains a Person field. A Person object contains a Page field.

public class Customer implements Serializable {
  private String name;
  private String symbol; // search integer in string format
  private int revenue;
  private int SSN; // search int
  private Person contact; // search nested object 
  ......
}
public class Person implements Serializable {
  private String name;
  private String email;
  private int revenue;
  private String address;
  private Page homepage;
  .......
}
public class Page implements Serializable {
  private int id; // search integer in int format
  private String title;
  private String content;
  final String desc = "At client and server JVM, initializing cache will create the LuceneServiceImpl object," 
     +" which is a singleton at each JVM."; 
  ......
}

 

Example to index on nested fields: following example demos how to index on nested field such as contact.homepage.title, or contact.email, each segment is a field name, not the type name. This will tell the system to find the parent and grandparent field,  because it's possible that several fields will have the same type. For example, Customer class could have 2 Person fields: Person contact and Person deliveryman. The email field to be indexed is from contact field, not deliveryman field. 

// Get LuceneService
LuceneService luceneService = LuceneServiceProvider.get(cache);

// Create Index on fields, some are fields in nested objects:
luceneService.createIndexFactory().addField("name").addField("symbol").addField("revenue").addField("SSN")
      .addField("contact.name").addField("contact.email").addField("contact.address").addField("contact.homepage.title")
      .create("customerIndex", "Customer");

// Now to create region
Region CustomerRegion = ((Cache)cache).createRegionFactory(shortcut).create("Customer");


2.  When querying, the syntax of nested field is the same as toplevel field, i.e. without parent field's name. For example: "email:tzhou12*". 

In order to 

 

// Create Query with nested objects
final StandardQueryParser queryParser = new StandardQueryParser(new KeywordAnalyzer());
LuceneQuery query = luceneService.createLuceneQueryFactory().setLimit(200).setPageSize(20)
  .create(indexName, regionName, querystring, "field1" /* default field */);

// Search using Query
PageableLuceneQueryResults<K,Object> results = query.findPages();

// Pagination
while (results.hasNext()) {
  results.next().stream().forEach(struct -> {
    Object value = struct.getValue();
    System.out.println("Key is "+struct.getKey()+", value is "+value);
  });
}
  • No labels