GitHub - java-flow/java-flow: Streaming programming and event driven lightweight development framework.

Streaming programming and event driven lightweight development framework.

Installing

Clone project git clone https://github.com/java-flow/java-flow.git
Publish to local Maven repository gradle publishToMavenLocal
To add a dependency using Maven, use the following:

<dependency>
    <groupId>com.javaflow</groupId>
    <artifactId>java-flow</artifactId>
    <version>1.0-SNAPSHOT</version>
</dependency>

Example

More examples can be viewed: Examples

TCP Server

Echo Server

@AllArgsConstructor
public class EchoFlow extends FlowDefiner {

    private final Integer listenPort;

    @Override
    public Flow define() {
        return new Flow("Echo")
                .next(new TcpIn(listenPort, STRING))
                .next(new TcpOut());
    }

    public static void main(String[] args) {
        new EchoFlow(8080).deploy();
    }

}

Print Time Server

@AllArgsConstructor
public class PrintTimeFlow extends FlowDefiner {

    private final Integer listenPort;

    @Override
    public Flow define() {
        return new Flow("PrintTime")
                .next(new TcpIn(listenPort, STRING))
                .next(msg -> msg.payload(ZonedDateTime.now()))
                .next(new TcpOut());
    }

    public static void main(String[] args) {
        new PrintTimeFlow(8080).deploy();
    }

}

TCP Client

Request

@AllArgsConstructor
public class RequestFlow extends FlowDefiner {

    private final String host;

    private final Integer port;

    @Override
    public Flow define() {
        return new Flow("Request")
                .next(new TcpRequest(host, port))
                .next(msg -> msg);
    }

    public static void main(String[] args) {
        Flow flow = new RequestFlow("localhost", 8080).deploy();
        flow.invoke(new Msg().payload("hello"));
    }

}

HTTP Server

Echo Server

@AllArgsConstructor
public class EchoFlow extends FlowDefiner {

    private final Integer listenPort;

    private final HttpMethod method;

    private final String url;

    @Override
    public Flow define() {
        return new Flow("Echo")
                .next(new HttpIn(listenPort, method, url))
                .next(new HttpOut());
    }

    public static void main(String[] args) {
        new EchoFlow(8080, HttpMethod.post, "/echo").deploy();
    }

}

Print Time Server

@AllArgsConstructor
public class PrintTimeFlow extends FlowDefiner {

    private final Integer listenPort;

    private final HttpMethod method;

    private final String url;

    @Override
    public Flow define() {
        return new Flow("PrintTime")
                .next(new HttpIn(listenPort, method, url))
                .next(msg -> msg.payload(ZonedDateTime.now()))
                .next(new HttpOut());
    }

    public static void main(String[] args) {
        new PrintTimeFlow(8080, HttpMethod.get, "/time").deploy();
    }

}

HTTP Client

Request

@AllArgsConstructor
public class RequestFlow extends FlowDefiner {

    @Override
    public Flow define() {
        return new Flow("Request")
                .next(msg -> {
                    msg.put(HttpRequest.Fields.method, "POST");
                    msg.put(HttpRequest.Fields.url, "http://localhost:8080/echo");
                    return msg;
                })
                .next(new HttpRequest())
                .next(msg -> msg);
    }

    public static void main(String[] args) {
        Flow flow = new RequestFlow().deploy();
        flow.invoke(new Msg().payload("hello"));
    }

}

Concept

There are mainly the following concepts:

Object
- Flow
- Node
  - Network
  - Function
- Msg
  - payload
Method
- Flow.next(node) Insert a node at the end of the flow.
- Flow.deploy() Deploy flow，Trigger all nodes onDeploy method.
- Flow.destroy() Destroy flow，Trigger all nodes onDestroy method.
- Flow.nextInvoke(node, msg) Invoke flow，Start from the specified node.
- Flow.invoke(msg) Invoke flow. Start from the first node.
- Node.invoke(msg) Call the node. The input is the message returned by the previous node, and the output message will be passed to the next node.
Event
- Node.onDeploy Triggered during flow deployment. The node resource can be initialized at this time.
- Node.onDestroy Triggered during flow destruction. The node resources can be released at this time.

Dependency

TcpIn、TcpOut used: Mina
HttpIn、HttpOut used: Spark

About

The inspiration of this project comes from Node-Red, Imagine that it would be a very flexible and simple development method if common basic functions were encapsulated into processing nodes, and each node provided unified input and output ports to form a business process. This will be suitable for simple application development.