Focus is the next generation cross language lightweight RPC framework. It can quickly and easily develop microservice applications, which greatly simplifies RPC programming.
Focus 是下一代跨语言、轻量级RPC框架。旨在帮助程序员快速的开发微服务应用程序，简化多运行环境下的RPC编程，可以很轻松的实现云端编程和移动端编程。
通常，评价一个 RPC 框架是否优秀、高效能，有 3 个基本标准：
-
简单易用，无侵入：不需要过多的研究使用文档，查看快速开始或 API 就能快速用起来，框架代码无需侵入业务代码就能完成调用。
-
抽象适度，可扩展：框架分层耦合合理、模块职责内聚、实现简洁易懂，能覆盖绝大多数场景，对特殊场景可通过设置或扩展来满足需求。
-
性能优越，可演进：“高性能”永远是一个绕不开的关注点，框架的实现也是编码能力的体现，保持 API 不变，但实现可持续迭代改进。
Focus 框架在高效能方面做了很多的努力，贯彻最小侵入性设计理念，坚持面向对象的SOLID原则，追求极简协议和代码简洁，能够让开发者和企业更轻松地集成和使用RPC框架。
对于希望使用和学习RPC框架的同学来说，选择一个高效、易用、灵活和可扩展的框架非常重要。Focus框架可以为他们提供更多的参考和选择，帮助他们更好地了解和掌握RPC框架的使用技巧和最佳实践。
- 跨语言支持。同时支持多种串行化协议：Jackson和Protobuff。
- 模块化API。模块化的客户端和服务端API，可扩展的系统架构核心小于1 MB。
- 分层架构。合理严谨的分层（包括API层、代理层、调用层、协议层、传输层）使得依赖最小化、可控，适用于更多运行环境。
- 可插拔的服务发现机制。支持 Consul，Nacos，Polaris等常见注册中心。
- 可插拔的调用拦截机制。可实现Logging、Tracing、Metrics、限流、熔断等服务安全、可观测性、服务治理功能。
- 支持同步调用、异步调用、泛化调用。满足各种场景下的不同诉求。
- 高效的自定义协议。二进制消息交换协议Photon和Focus的RPC协议。
- 不同级别的服务控制。全局级别、服务级别的序列化、压缩、超时、重试设置，方法级别的超时、重试设置。
- Spring boot 集成支持友好。简化Spring应用的集成、开发难度。
- Modular client and server APIs, scalable system architecture, and framework core less than 1 MB in size.
- Support a variety of serialization protocol at the same time - Jackson、Protobuff、Protostuff
- Layered architecture, including API layer, Proxy layer, Invoke layer, Protocol layer, Transport layer
- Pluggable invoke interception mechanism, that facilitates extensions such as service security, observability, and service governance.
- Out of the box client-side and server-side API
- Spring boot starter integration friendly
- Support synchronous, asynchronous and generalized calls
- Efficient custom protocol (Photon message exchange protocol and Focus RPC protocol)
- High-performance NIO socket framework support - Netty4
The quick start gives a basic example of running client and server on the same machine. For more advanced examples, please refer to the example project : focus-examples. For the detailed information about using and developing Focus, please jump to Documents.
The minimum requirements to run the quick start are:
- create maven project focus-quickstart and add dependencies to pom.
<dependencies>
<dependency>
<groupId>com.dinstone.focus</groupId>
<artifactId>focus-server-photon</artifactId>
<version>1.4.0</version>
<type>pom</type>
</dependency>
<dependency>
<groupId>com.dinstone.focus</groupId>
<artifactId>focus-client-photon</artifactId>
<version>1.4.0</version>
<type>pom</type>
</dependency>
<dependency>
<groupId>com.dinstone.focus</groupId>
<artifactId>focus-serialize-json</artifactId>
<version>1.4.0</version>
</dependency>
</dependencies>- create FooService interface.
package focus.quickstart;
public interface FooService {
public String hello(String name);
public CompletableFuture<String> async(String name);
}- create FooService implement.
package focus.quickstart.server;
import focus.quickstart.FooService;
public class FooServiceImpl implements FooService {
public String hello(String name) {
return "hello " + name;
}
public CompletableFuture<String> async(String name) {
return CompletableFuture.completedFuture("async hello " + name);
}
}- create focus server and exporting service.
package focus.quickstart.server;
import java.io.IOException;
import com.dinstone.focus.server.FocusServer;
import com.dinstone.focus.server.ServerOptions;
import com.dinstone.loghub.Logger;
import com.dinstone.loghub.LoggerFactory;
import focus.quickstart.FooService;
public class FocusServerBootstrap {
private static final Logger LOG = LoggerFactory.getLogger(FocusServerBootstrap.class);
public static void main(String[] args) {
ServerOptions serverOptions = new ServerOptions("focus.quickstart.server").listen("localhost", 3333);
FocusServer server = new FocusServer(serverOptions);
// exporting service
server.exporting(FooService.class, new FooServiceImpl());
server.start();
LOG.info("server start");
try {
System.in.read();
} catch (IOException e) {
e.printStackTrace();
}
server.close();
LOG.info("server stop");
}
}- create focus client to importing service and invoke RPC.
package focus.quickstart.client;
import com.dinstone.focus.client.ClientOptions;
import com.dinstone.focus.client.FocusClient;
import focus.quickstart.FooService;
public class FocusClientBootstrap {
public static void main(String[] args) throws Exception {
ClientOptions option = new ClientOptions("focus.quickstart.client").connect("localhost", 3333);
FocusClient client = new FocusClient(option);
try {
FooService fooService = client.importing(FooService.class);
String reply = fooService.hello("dinstone");
System.out.println(reply);
CompletableFuture<String> rf = fooService.async("dinstone");
System.out.println(rf.get());
} finally {
client.close();
}
}
}- another way to call RPC asynchronously is to create an asynchronous interface class in client side.
package focus.quickstart.client;
import java.util.concurrent.CompletableFuture;
public interface FooAsyncService {
public CompletableFuture<String> hello(String name);
}- create focus client to importing service and async invoke RPC.
package focus.quickstart.client;
import java.util.concurrent.CompletableFuture;
import com.dinstone.focus.client.ClientOptions;
import com.dinstone.focus.client.FocusClient;
import com.dinstone.focus.client.ImportOptions;
public class FocusClientAsyncCallBootstrap {
public static void main(String[] args) throws Exception {
ClientOptions option = new ClientOptions("focus.quickstart.client").connect("localhost", 3333);
FocusClient client = new FocusClient(option);
try {
ImportOptions importOptions = new ImportOptions("focus.quickstart.api.FooService");
FooAsyncService fooService = client.importing(FooAsyncService.class, importOptions);
CompletableFuture<String> replyFuture = fooService.hello("dinstone");
System.out.println(replyFuture.get());
} finally {
client.close();
}
}
}-
the generalized call does not need to build the client interface class
-
create focus client to importing GenericService and sync/async invoke RPC.
package focus.quickstart.client;
import java.util.concurrent.CompletableFuture;
import com.dinstone.focus.client.ClientOptions;
import com.dinstone.focus.client.FocusClient;
import com.dinstone.focus.client.GenericService;
public class FocusClientGenericCallBootstrap {
public static void main(String[] args) throws Exception {
ClientOptions option = new ClientOptions("focus.quickstart.client").connect("localhost", 3333);
FocusClient client = new FocusClient(option);
try {
GenericService genericService = client.generic("focus.quickstart.server",
"focus.quickstart.api.FooService");
String reply = genericService.sync(String.class, "hello", "dinstone");
System.out.println("sync call reply : " + reply);
CompletableFuture<String> replyFuture = genericService.async(String.class, "hello", "dinstone");
System.out.println("async call reply : " + replyFuture.get());
} finally {
client.close();
}
}
}1.Set server parameters, enable SSL in the accept options, and set certificate information.
package focus.quickstart.ssl;
import java.io.IOException;
import java.security.cert.X509Certificate;
import com.dinstone.focus.server.FocusServer;
import com.dinstone.focus.server.ServerOptions;
import com.dinstone.focus.transport.photon.PhotonAcceptOptions;
import focus.quickstart.api.FooService;
import focus.quickstart.service.FooServiceImpl;
import io.netty.handler.ssl.util.SelfSignedCertificate;
public class SslFocusServerBootstrap {
public static void main(String[] args) throws Exception {
// setting ssl
SelfSignedCertificate cert = new SelfSignedCertificate();
PhotonAcceptOptions acceptOptions = new PhotonAcceptOptions();
acceptOptions.setEnableSsl(true);
acceptOptions.setPrivateKey(cert.key());
acceptOptions.setCertChain(new X509Certificate[] { cert.cert() });
// setting accept options
ServerOptions serverOptions = new ServerOptions("focus.quickstart.server").listen("localhost", 3333)
.setAcceptOptions(acceptOptions);
FocusServer server = new FocusServer(serverOptions);
// exporting service
server.exporting(FooService.class, new FooServiceImpl());
server.start();
try {
System.in.read();
} catch (IOException e) {
e.printStackTrace();
}
server.close();
}
}2.Set client parameters and enable SSL in the connection options.
package focus.quickstart.ssl;
import java.util.concurrent.CompletableFuture;
import com.dinstone.focus.client.ClientOptions;
import com.dinstone.focus.client.FocusClient;
import com.dinstone.focus.transport.photon.PhotonConnectOptions;
import focus.quickstart.api.FooService;
public class SslFocusClientBootstrap {
public static void main(String[] args) throws Exception {
PhotonConnectOptions connectOptions = new PhotonConnectOptions();
// setting ssl
connectOptions.setEnableSsl(true);
ClientOptions clientOptions = new ClientOptions("focus.quickstart.client").connect("localhost", 3333)
.setConnectOptions(connectOptions);
FocusClient client = new FocusClient(clientOptions);
try {
FooService fooService = client.importing(FooService.class);
String reply = fooService.hello("dinstone");
System.out.println(reply);
CompletableFuture<String> rf = fooService.async("dinstone");
System.out.println(rf.get());
} finally {
client.close();
}
}
}Focus is released under the Apache License 2.0.