4.3. 嵌入式查询
当您将 Data Grid 作为自定义应用程序的库添加时,使用嵌入式查询。
使用嵌入式查询不需要 protobuf 映射。索引和查询都在 Java 对象之上完成。
4.3.1. 嵌入式查询示例 复制链接链接已复制到粘贴板!
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:
infinispan.xml
<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。
Book.java
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>();
}
Author.java
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。
QueryExample.java
// 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();
4.3.2. 映射实体 复制链接链接已复制到粘贴板!
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。
通过注解注册密钥转换程序
您可以使用 org.infinispan.query.Transformable 标注密钥类,您的自定义转换器实施将自动获取:
@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 ...
}
}
通过缓存索引配置注册密钥转换程序
在嵌入式和服务器配置中使用 key-transformers xml 元素:
<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;