LangGraph4j 学习系列(1)-顺序工作流

import org.bsc.langgraph4j.action.NodeAction;
import org.bsc.langgraph4j.state.AgentState;

import java.util.Map;

/**
 * @author junmingyang
 */
public class Node1Action implements NodeAction<AgentState> {
    @Override
    public Map<String, Object> apply(AgentState state) throws Exception {
        System.out.println("current Node: node-1");
        return Map.of("myData", "node1-my-value",
                "node1Key", "node1-value");
    }
}

import org.bsc.langgraph4j.action.NodeAction;
import org.bsc.langgraph4j.state.AgentState;

import java.util.Map;

/**
 * @author junmingyang
 */
public class Node2Action implements NodeAction<AgentState> {
    @Override
    public Map<String, Object> apply(AgentState state) throws Exception {
        System.out.println("current Node: node-2");
        return Map.of("myData", "node2-my-value",
                "node2Key", "node2-value");
    }
}

import org.bsc.langgraph4j.GraphDefinition;
import org.bsc.langgraph4j.GraphRepresentation;
import org.bsc.langgraph4j.GraphStateException;
import org.bsc.langgraph4j.StateGraph;
import org.bsc.langgraph4j.state.AgentState;

import java.util.Map;

import static org.bsc.langgraph4j.action.AsyncNodeAction.node_async;

/**
 * SequenceGraphApplication 类演示了如何使用 LangGraph4j 构建和执行一个简单的序列图。
 * 该应用程序创建了一个包含两个节点的序列图，节点按顺序执行：
 * START -> node-1 -> node-2 -> END
 * 
 * @author 菩提树下的杨过(yjmyzz.cnblogs.com)
 * @since 1.0
 */
public class SequenceGraphApplication {

    public static void main(String[] args) throws GraphStateException {
        StateGraph<AgentState> sequenceGraph = getSequenceGraph();

        //打印图的mermaid代码
        System.out.println(sequenceGraph.getGraph(GraphRepresentation.Type.MERMAID, "Sequence Graph", true).content());

        //编译图并运行（初始数据值为 test->test-init-value
        sequenceGraph
                .compile() //编译
                .invoke(Map.of("test", "test-init-value")) //运行（并赋初始值)
                .ifPresent(c -> {
                    //运行结束后，会执行本段逻辑
                    System.out.println(c.data());
                });

    }

    public static StateGraph<AgentState> getSequenceGraph() throws GraphStateException {
        return new StateGraph<>(AgentState::new)
                //向图中添加2个节点
                .addNode("node-1", node_async(new Node1Action()))
                .addNode("node-2", node_async(new Node2Action()))
                //加一条边（开始->node1)
                .addEdge(GraphDefinition.START, "node-1")
                //加1条边(node1->node2)
                .addEdge("node-1", "node-2")
                //加1条边(node2->结束)
                .addEdge("node-2", GraphDefinition.END);
    }


}

current Node: node-1
current Node: node-2
{node1Key=node1-value, test=test-init-value, node2Key=node2-value, myData=node2-my-value}