第 3 章 查询远程缓存
您可以在 Data Grid 服务器上索引和查询远程缓存。
3.1. 从 Hot Rod Java 客户端查询缓存
Data Grid 可让您通过 Hot Rod 端点，以编程方式从 Java 客户端查询远程缓存。此流程解释了如何索引查询存储书签实例的远程缓存。
先决条件
-
将 ProtoStream 处理器添加到
pom.xml中。
Data Grid 为 @ProtoField 和 @ProtoDoc 注解提供此处理器，以便您可以生成 Protobuf 模式并执行查询。
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.infinispan</groupId>
<artifactId>infinispan-bom</artifactId>
<version>${version.infinispan}</version>
<type>pom</type>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.infinispan.protostream</groupId>
<artifactId>protostream-processor</artifactId>
<scope>provided</scope>
</dependency>
</dependencies>流程
在您的类中添加索引注解，如下例所示：
Book.java
import org.infinispan.protostream.annotations.ProtoDoc; import org.infinispan.protostream.annotations.ProtoFactory; import org.infinispan.protostream.annotations.ProtoField; @ProtoDoc("@Indexed") public class Book { @ProtoDoc("@Field(index=Index.YES, analyze = Analyze.YES, store = Store.NO)") @ProtoField(number = 1) final String title; @ProtoDoc("@Field(index=Index.YES, analyze = Analyze.YES, store = Store.NO)") @ProtoField(number = 2) final String description; @ProtoDoc("@Field(index=Index.YES, analyze = Analyze.YES, store = Store.NO)") @ProtoField(number = 3, defaultValue = "0") final int publicationYear; @ProtoFactory Book(String title, String description, int publicationYear) { this.title = title; this.description = description; this.publicationYear = publicationYear; } // public Getter methods omitted for brevity }在新类中实施
SerializationContextInitializer接口，然后添加@AutoProtoSchemaBuilder注释。-
使用
includeClasses参数引用包含@ProtoField和@ProtoDoc注解的类。 -
使用
schemaFileName和schemaFilePath参数定义您生成的和文件系统路径的 Protobuf 模式的名称。 使用
schemaPackageName参数指定 Protobuf 模式的软件包名称。RemoteQueryInitializer.java
import org.infinispan.protostream.SerializationContextInitializer; import org.infinispan.protostream.annotations.AutoProtoSchemaBuilder; @AutoProtoSchemaBuilder( includeClasses = { Book.class }, schemaFileName = "book.proto", schemaFilePath = "proto/", schemaPackageName = "book_sample") public interface RemoteQueryInitializer extends SerializationContextInitializer { }
-
使用
编译您的项目。
此流程中的代码示例生成
proto/book.proto模式和注释Book类的RemoteQueryInitializerImpl.java实现。
后续步骤
创建一个远程缓存，将数据仓库配置为索引您的实体。例如，以下远程缓存会索引您在上一步中生成的 book.proto 模式中的书签实体：
<replicated-cache name="books">
<indexing>
<indexed-entities>
<indexed-entity>book_sample.Book</indexed-entity>
</indexed-entities>
</indexing>
</replicated-cache>
以下 RemoteQuery 类执行以下操作：
-
将
RemoteQueryInitializerImplserialization 上下文注册到 Hot Rod Java 客户端。 -
将 Protobuf 模式
书.proto注册到 Data Grid Server。 -
将两个书签
实例添加到远程缓存中。 - 执行与标题中的关键字匹配的全文本查询。
RemoteQuery.java
package org.infinispan;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;
import org.infinispan.client.hotrod.RemoteCache;
import org.infinispan.client.hotrod.RemoteCacheManager;
import org.infinispan.client.hotrod.Search;
import org.infinispan.client.hotrod.configuration.ConfigurationBuilder;
import org.infinispan.query.dsl.Query;
import org.infinispan.query.dsl.QueryFactory;
import org.infinispan.query.remote.client.ProtobufMetadataManagerConstants;
public class RemoteQuery {
public static void main(String[] args) throws Exception {
ConfigurationBuilder clientBuilder = new ConfigurationBuilder();
// RemoteQueryInitializerImpl is generated
clientBuilder.addServer().host("127.0.0.1").port(11222)
.security().authentication().username("user").password("user")
.addContextInitializers(new RemoteQueryInitializerImpl());
RemoteCacheManager remoteCacheManager = new RemoteCacheManager(clientBuilder.build());
// Grab the generated protobuf schema and registers in the server.
Path proto = Paths.get(RemoteQuery.class.getClassLoader()
.getResource("proto/book.proto").toURI());
String protoBufCacheName = ProtobufMetadataManagerConstants.PROTOBUF_METADATA_CACHE_NAME;
remoteCacheManager.getCache(protoBufCacheName).put("book.proto", Files.readString(proto));
// Obtain the 'books' remote cache
RemoteCache<Object, Object> remoteCache = remoteCacheManager.getCache("books");
// Add some Books
Book book1 = new Book("Infinispan in Action", "Learn Infinispan with using it", 2015);
Book book2 = new Book("Cloud-Native Applications with Java and Quarkus", "Build robust and reliable cloud applications", 2019);
remoteCache.put(1, book1);
remoteCache.put(2, book2);
// Execute a full-text query
QueryFactory queryFactory = Search.getQueryFactory(remoteCache);
Query<Book> query = queryFactory.create("FROM book_sample.Book WHERE title:'java'");
List<Book> list = query.execute().list(); // Voila! We have our book back from the cache!
}
}
其他资源
- Marshalling 和 Encoding Data，以了解有关创建序列化上下文和注册 Protobuf 模式的更多信息。
-
ProtoStream 注解，以了解有关
@ProtoField、@ProtoDoc和@AutoProtoSchemaBuilder注解的更多信息。
