4.3. 嵌入式查询

我们将将 Book 实例存储在名为"books"的数据网格缓存中。将对 本书实例进行索引，因此我们为缓存配置启用索引：

<distributed-cache name="books">
  <indexing path="${user.home}/index">
    <indexed-entities>
      <indexed-entity>org.infinispan.sample.Book</indexed-entity>
    </indexed-entities>
  </indexing>
</distributed-cache>

获取缓存：

import org.infinispan.Cache;
import org.infinispan.manager.DefaultCacheManager;
import org.infinispan.manager.EmbeddedCacheManager;

EmbeddedCacheManager manager = new DefaultCacheManager("infinispan.xml");
Cache<String, Book> cache = manager.getCache("books");

每个 Book 将按照以下示例定义；我们必须选择索引哪些属性；对于每个属性，我们可以选择使用 Hibernate Search 项目中定义的注释选择高级索引选项。

package org.infinispan.sample;

import java.time.LocalDate;
import java.util.HashSet;
import java.util.Set;

import org.hibernate.search.mapper.pojo.mapping.definition.annotation.*;

// Annotate values with @Indexed to add them to indexes
// Annotate each fields according to how you want to index it
@Indexed
public class Book {
   @FullTextField
   String title;

   @FullTextField
   String description;

   @KeywordField
   String isbn;

   @GenericField
   LocalDate publicationDate;

   @IndexedEmbedded
   Set<Author> authors = new HashSet<Author>();
}

package org.infinispan.sample;

import org.hibernate.search.mapper.pojo.mapping.definition.annotation.FullTextField;

public class Author {
   @FullTextField
   String name;

   @FullTextField
   String surname;
}

假设我们在我们的 Data Grid Cache 中存储了多个 Book 实例，我们可以根据以下示例所示搜索任何匹配字段。

// Get the query factory from the cache
QueryFactory queryFactory = org.infinispan.query.Search.getQueryFactory(cache);

// Create an Ickle query that performs a full-text search using the ':' operator on the 'title' and 'authors.name' fields
// You can perform full-text search only on indexed caches
Query<Book> fullTextQuery = queryFactory.create("FROM org.infinispan.sample.Book b WHERE b.title:'infinispan' AND b.authors.name:'sanne'");

// Use the '=' operator to query fields in caches that are indexed or not
// Non full-text operators apply only to fields that are not analyzed
Query<Book> exactMatchQuery=queryFactory.create("FROM org.infinispan.sample.Book b WHERE b.isbn = '12345678' AND b.authors.name : 'sanne'");

// You can use full-text and non-full text operators in the same query
Query<Book> query=queryFactory.create("FROM org.infinispan.sample.Book b where b.authors.name : 'Stephen' and b.description : (+'dark' -'tower')");

// Get the results
List<Book> found=query.execute().list();

Data Grid 依赖于 Hibernate Search 的 API，以定义在实体级别索引的精细配置。此配置包括注解哪些字段，这些分析器应使用，如何映射嵌套对象等。Hibernate Search 手册中 提供了详细的文档。

@DocumentId

与 Hibernate Search 不同，使用 @DocumentId 将字段标记为标识符不适用于 Data Grid 值；在 Data Grid 中，所有 @Indexed 对象的标识符是用于存储值的密钥。您仍然可以使用 @Transformable、自定义类型和自定义 FieldBridge 实施的组合来自定义键的索引方式。

@Transformable 键

每个值的密钥也需要索引，必须在 String 中转换密钥实例。Data Grid 包括一些默认的转换例程来编码常见的原语，但要使用一个自定义密钥，您必须提供一个 org.infinispan.query.Transformer 的实现。

@Transformable(transformer = CustomTransformer.class)
public class CustomKey {
   ...
}

public class CustomTransformer implements Transformer {
   @Override
   public Object fromString(String s) {
      ...
      return new CustomKey(...);
   }

   @Override
   public String toString(Object customType) {
      CustomKey ck = (CustomKey) customType;
      return ...
   }
}

<replicated-cache name="test">
  <indexing auto-config="true">
    <key-transformers>
      <key-transformer key="com.mycompany.CustomKey"
                       transformer="com.mycompany.CustomTransformer"/>
    </key-transformers>
  </indexing>
</replicated-cache>

或者，使用 Java 配置 API (embedded 模式)：

   ConfigurationBuilder builder = ...
   builder.indexing().enable()
         .addKeyTransformer(CustomKey.class, CustomTransformer.class);

程序映射

除了使用注解将实体映射到索引外，还可以以编程方式进行配置。

在以下示例中，我们映射了一个要存储在网格中的对象 Author，并可在两个属性上搜索，但没有注解类。

import org.apache.lucene.search.Query;
import org.hibernate.search.cfg.Environment;
import org.hibernate.search.cfg.SearchMapping;
import org.hibernate.search.query.dsl.QueryBuilder;
import org.infinispan.Cache;
import org.infinispan.configuration.cache.Configuration;
import org.infinispan.configuration.cache.ConfigurationBuilder;
import org.infinispan.configuration.cache.Index;
import org.infinispan.manager.DefaultCacheManager;
import org.infinispan.query.CacheQuery;
import org.infinispan.query.Search;
import org.infinispan.query.SearchManager;

import java.io.IOException;
import java.lang.annotation.ElementType;
import java.util.Properties;

SearchMapping mapping = new SearchMapping();
mapping.entity(Author.class).indexed()
       .property("name", ElementType.METHOD).field()
       .property("surname", ElementType.METHOD).field();

Properties properties = new Properties();
properties.put(Environment.MODEL_MAPPING, mapping);
properties.put("hibernate.search.[other options]", "[...]");

Configuration infinispanConfiguration = new ConfigurationBuilder()
        .indexing().index(Index.NONE)
        .withProperties(properties)
        .build();

DefaultCacheManager cacheManager = new DefaultCacheManager(infinispanConfiguration);

Cache<Long, Author> cache = cacheManager.getCache();
SearchManager sm = Search.getSearchManager(cache);

Author author = new Author(1, "Manik", "Surtani");
cache.put(author.getId(), author);

QueryBuilder qb = sm.buildQueryBuilderForClass(Author.class).get();
Query q = qb.keyword().onField("name").matching("Manik").createQuery();
CacheQuery cq = sm.getQuery(q, Author.class);
assert cq.getResultSize() == 1;