java 工作流引擎设计实现解析流程定义文件

2023-05-19 20:05:18 解析 流程 工作流

引言

在上一篇我们手动构建了一个流程对象并简单打印执行，其构建流程对象的方式并不是很友好。为了更方便的构建流程对象，我们采用全新的方式，即解析基础篇提到的流程定义文件，并将其转成流程模型。 以下是要解析的样例文件：

src/test/resources/leave.JSON

{
  "name": "leave",
  "displayName": "请假",
  "instanceUrl": "leaveFORM",
  "nodes": [
    {
      "id": "start",
      "type": "snaker:start",
      "x": 340,
      "y": 160,
      "properties": {
        "width": "120",
        "height": "80"
      },
      "text": {
        "x": 340,
        "y": 200,
        "value": "开始"
      }
    },
    {
      "id": "apply",
      "type": "snaker:task",
      "x": 520,
      "y": 160,
      "properties": {
        "assignee": "approve.operator",
        "taskType": "Major",
        "performType": "ANY",
        "autoExecute": "N",
        "width": "120",
        "height": "80",
        "field": {
          "userKey": "1"
        }
      },
      "text": {
        "x": 520,
        "y": 160,
        "value": "请假申请"
      }
    },
    {
      "id": "approveDept",
      "type": "snaker:task",
      "x": 740,
      "y": 160,
      "properties": {
        "assignmentHandler": "com.mldong.config.FlowAssignmentHandler",
        "taskType": "Major",
        "performType": "ANY",
        "autoExecute": "N",
        "width": "120",
        "height": "80"
      },
      "text": {
        "x": 740,
        "y": 160,
        "value": "部门领导审批"
      }
    },
    {
      "id": "end",
      "type": "snaker:end",
      "x": 980,
      "y": 160,
      "properties": {
        "width": "120",
        "height": "80"
      },
      "text": {
        "x": 980,
        "y": 200,
        "value": "结束"
      }
    }
  ],
  "edges": [
    {
      "id": "t1",
      "type": "snaker:transition",
      "sourceNodeId": "start",
      "targetNodeId": "apply",
      "startPoint": {
        "x": 358,
        "y": 160
      },
      "endPoint": {
        "x": 460,
        "y": 160
      },
      "properties": {
        "height": 80,
        "width": 120
      },
      "pointsList": [
        {
          "x": 358,
          "y": 160
        },
        {
          "x": 460,
          "y": 160
        }
      ]
    },
    {
      "id": "t2",
      "type": "snaker:transition",
      "sourceNodeId": "apply",
      "targetNodeId": "approveDept",
      "startPoint": {
        "x": 580,
        "y": 160
      },
      "endPoint": {
        "x": 680,
        "y": 160
      },
      "properties": {
        "height": 80,
        "width": 120
      },
      "pointsList": [
        {
          "x": 580,
          "y": 160
        },
        {
          "x": 680,
          "y": 160
        }
      ]
    },
    {
      "id": "t3",
      "type": "snaker:transition",
      "sourceNodeId": "approveDept",
      "targetNodeId": "end",
      "startPoint": {
        "x": 800,
        "y": 160
      },
      "endPoint": {
        "x": 962,
        "y": 160
      },
      "properties": {
        "height": 80,
        "width": 120
      },
      "pointsList": [
        {
          "x": 800,
          "y": 160
        },
        {
          "x": 830,
          "y": 160
        },
        {
          "x": 830,
          "y": 160
        },
        {
          "x": 932,
          "y": 160
        },
        {
          "x": 932,
          "y": 160
        },
        {
          "x": 962,
          "y": 160
        }
      ]
    }
  ]
}

类图

流程图

代码实现

model/logicflow/LfPoint.java

package com.mldong.flow.engine.model.logicflow;
import lombok.Data;
import java.io.Serializable;

@Data
public class LfPoint implements Serializable {
    private int x; // x轴坐标
    private int y; // y轴坐标
}

LogicFlow模型对象

model/logicflow/LfNode.java

package com.mldong.flow.engine.model.logicflow;
import cn.hutool.core.lang.Dict;
import lombok.Data;
import java.io.Serializable;

@Data
public class LfNode implements Serializable {
    private String id; // 节点唯一id
    private String type; // 节点类型
    private int x; // 节点中心点x轴坐标
    private int y; // 节点中心点y轴坐标
    Dict properties; // 节点属性
    Dict text; // 节点文本
}

model/logicflow/LfEdge.java

package com.mldong.flow.engine.model.logicflow;
import cn.hutool.core.lang.Dict;
import lombok.Data;
import java.io.Serializable;
import java.util.List;

@Data
public class LfEdge implements Serializable {
    private String id; // 边唯一id
    private String type; // 边类型
    private String sourceNodeId; // 源节点id
    private String targetNodeId; // 目标节点id
    private Dict properties; // 边属性
    private Dict text; // 边文本
    private LfPoint startPoint; // 边开始点坐标
    private LfPoint endPoint; // 边结束点坐标
    private List<LfPoint> pointsList; // 边所有点集合
}

model/logicflow/LfModel.java

package com.mldong.flow.engine.model.logicflow;
import com.mldong.flow.engine.model.BaseModel;
import lombok.Data;
import java.util.List;

@Data
public class LfModel extends BaseModel {
    private String type; // 流程定义分类
    private String expireTime;// 过期时间（常量或变量）
    private String instanceUrl; // 启动实例的url,前后端分离后，定义为路由名或或路由地址
    private String instanceNoClass; // 启动流程时，流程实例的流水号生成类
    private List<LfNode> nodes; // 节点集合
    private List<LfEdge> edges; // 边集合
}

解析类

parser/NodeParser.java

package com.mldong.flow.engine.parser;
import com.mldong.flow.engine.model.NodeModel;
import com.mldong.flow.engine.model.logicflow.LfEdge;
import com.mldong.flow.engine.model.logicflow.LfNode;
import java.util.List;

public interface NodeParser {
    String NODE_NAME_PREFIX="snaker:"; // 节点名称前辍
    String TEXT_VALUE_KEY = "value"; // 文本值
    String WIDTH_KEY = "width"; // 节点宽度
    String HEIGHT_KEY = "height"; // 节点高度
    String PRE_INTERCEPTORS_KEY = "preInterceptors"; // 前置拦截器
    String POST_INTERCEPTORS_KEY = "postInterceptors"; // 后置拦截器
    String EXPR_KEY = "expr"; // 表达式key
    String HANDLE_CLASS_KEY = "handleClass"; // 表达式处理类
    String FORM_KEY = "form"; // 表单标识
    String ASSIGNEE_KEY = "assignee"; // 参与人
    String ASSIGNMENT_HANDLE_KEY = "assignmentHandler"; // 参与人处理类
    String TASK_TYPE_KEY = "taskType"; // 任务类型(主办/协办)
    String PERFORM_TYPE_KEY = "performType"; // 参与类型(普通参与/会签参与)
    String REMINDER_TIME_KEY = "reminderTime"; // 提醒时间
    String REMINDER_REPEAT_KEY = "reminderRepeat"; // 重复提醒间隔
    String EXPIRE_TIME_KEY = "expireTime"; // 期待任务完成时间变量key
    String AUTH_EXECUTE_KEY = "autoExecute"; // 到期是否自动执行Y/N
    String CALLBACK_KEY = "callback"; // 自动执行回调类
    String EXT_FIELD_KEY = "field"; // 自定义扩展属性
    
    void parse(LfNode lfNode, List<LfEdge> edges);
    
    NodeModel getModel();
}

parser/AbstractNodeParser.java

package com.mldong.flow.engine.parser;
import cn.hutool.core.collection.CollectionUtil;
import cn.hutool.core.convert.Convert;
import cn.hutool.core.lang.Dict;
import cn.hutool.core.util.ObjectUtil;
import cn.hutool.core.util.StrUtil;
import com.mldong.flow.engine.model.NodeModel;
import com.mldong.flow.engine.model.TransitionModel;
import com.mldong.flow.engine.model.logicflow.LfEdge;
import com.mldong.flow.engine.model.logicflow.LfNode;
import java.util.List;
import java.util.stream.Collectors;

public abstract class AbstractNodeParser implements NodeParser {
    // 节点模型对象
    protected NodeModel nodeModel;
    @Override
    public void parse(LfNode lfNode, List&lt;LfEdge&gt; edges) {
        nodeModel = newModel();
        // 解析基本信息
        nodeModel.setName(lfNode.getId());
        if(ObjectUtil.isNotNull(lfNode.getText())) {
            nodeModel.setDisplayName(lfNode.getText().getStr(TEXT_VALUE_KEY));
        }
        Dict properties = lfNode.getProperties();
        // 解析布局属性
        int x = lfNode.getX();
        int y = lfNode.getY();
        int w = Convert.toInt(properties.get(WIDTH_KEY),0);
        int h = Convert.toInt(properties.get(HEIGHT_KEY),0);
        nodeModel.setLayout(StrUtil.format("{},{},{},{}",x,y,w,h));
        // 解析拦截器
        nodeModel.setPreInterceptors(properties.getStr(PRE_INTERCEPTORS_KEY));
        nodeModel.setPostInterceptors(properties.getStr(POST_INTERCEPTORS_KEY));
        // 解析输出边
        List&lt;LfEdge&gt; nodeEdges = getEdgeBySourceNodeId(lfNode.getId(), edges);
        nodeEdges.forEach(edge-&gt;{
            TransitionModel transitionModel = new TransitionModel();
            transitionModel.setName(edge.getId());
            transitionModel.setTo(edge.getTargetNodeId());
            transitionModel.setSource(nodeModel);
            transitionModel.setExpr(edge.getProperties().getStr(EXPR_KEY));
            if(CollectionUtil.isNotEmpty(edge.getPointsList())) {
                // x1,y1;x2,y2;x3,y3……
                transitionModel.setG(edge.getPointsList().stream().map(point-&gt;{
                    return point.getX()+","+point.getY();
                }).collect(Collectors.joining(";")));
            } else {
                if(ObjectUtil.isNotNull(edge.getStartPoint()) &amp;&amp; ObjectUtil.isNotNull(edge.getEndPoint())) {
                    int startPointX = edge.getStartPoint().getX();
                    int startPointY = edge.getStartPoint().getY();
                    int endPointX = edge.getEndPoint().getX();
                    int endPointY = edge.getEndPoint().getY();
                    transitionModel.setG(StrUtil.format("{},{};{},{}", startPointX, startPointY, endPointX, endPointY));
                }
            }
            nodeModel.getOutputs().add(transitionModel);
        });
        // 调用子类特定解析方法
        parseNode(lfNode);
    }
    
    public abstract void parseNode(LfNode lfNode);
    
    public abstract NodeModel newModel();
    @Override
    public NodeModel getModel() {
        return nodeModel;
    }
    
    private List&lt;LfEdge&gt; getEdgeByTargetNodeId(String targetNodeId,List&lt;LfEdge&gt; edges) {
        return edges.stream().filter(edge-&gt;{
            return edge.getTargetNodeId().equals(targetNodeId);
        }).collect(Collectors.toList());
    }
    
    private List&lt;LfEdge&gt; getEdgeBySourceNodeId(String sourceNodeId,List&lt;LfEdge&gt; edges) {
        return edges.stream().filter(edge-&gt;{
            return edge.getSourceNodeId().equals(sourceNodeId);
        }).collect(Collectors.toList());
    }
}

parser/impl/StartParser.java

package com.mldong.flow.engine.parser.impl;
import com.mldong.flow.engine.model.NodeModel;
import com.mldong.flow.engine.model.StartModel;
import com.mldong.flow.engine.model.logicflow.LfNode;
import com.mldong.flow.engine.parser.AbstractNodeParser;

public class StartParser extends AbstractNodeParser {
    @Override
    public void parseNode(LfNode lfNode) {
    }
    @Override
    public NodeModel newModel() {
        return new StartModel();
    }
}

parser/impl/EndParser.java

package com.mldong.flow.engine.parser.impl;
import com.mldong.flow.engine.model.EndModel;
import com.mldong.flow.engine.model.NodeModel;
import com.mldong.flow.engine.model.logicflow.LfNode;
import com.mldong.flow.engine.parser.AbstractNodeParser;

public class EndParser extends AbstractNodeParser {
    @Override
    public void parseNode(LfNode lfNode) {
    }
    @Override
    public NodeModel newModel() {
        return new EndModel();
    }
}

parser/impl/TaskParser.java

package com.mldong.flow.engine.parser.impl;
import cn.hutool.core.convert.Convert;
import cn.hutool.core.lang.Dict;
import com.mldong.flow.engine.enums.TaskPerformTypeEnum;
import com.mldong.flow.engine.enums.TaskTypeEnum;
import com.mldong.flow.engine.model.NodeModel;
import com.mldong.flow.engine.model.TaskModel;
import com.mldong.flow.engine.model.logicflow.LfNode;
import com.mldong.flow.engine.parser.AbstractNodeParser;

public class TaskParser extends AbstractNodeParser {
    
    @Override
    public void parseNode(LfNode lfNode) {
        TaskModel taskModel = (TaskModel)nodeModel;
        Dict properties = lfNode.getProperties();
        taskModel.setForm(properties.getStr(FORM_KEY));
        taskModel.setAssignee(properties.getStr(ASSIGNEE_KEY));
        taskModel.setAssignmentHandler(properties.getStr(ASSIGNMENT_HANDLE_KEY));
        taskModel.setTaskType(TaskTypeEnum.codeOf(properties.getInt(TASK_TYPE_KEY)));
        taskModel.setPerformType(TaskPerformTypeEnum.codeOf(properties.getInt(PERFORM_TYPE_KEY)));
        taskModel.setReminderTime(properties.getStr(REMINDER_TIME_KEY));
        taskModel.setReminderRepeat(properties.getStr(REMINDER_REPEAT_KEY));
        taskModel.setExpireTime(properties.getStr(EXPIRE_TIME_KEY));
        taskModel.setAutoExecute(properties.getStr(AUTH_EXECUTE_KEY));
        taskModel.setCallback(properties.getStr(CALLBACK_KEY));
        // 自定义扩展属性
        Object field = properties.get(EXT_FIELD_KEY);
        if(field!=null) {
            taskModel.setExt(Convert.convert(Dict.class, field));
        }
    }
    @Override
    public NodeModel newModel() {
        return new TaskModel();
    }
}

parser/impl/ForkParser.java

package com.mldong.flow.engine.parser.impl;
import com.mldong.flow.engine.model.ForkModel;
import com.mldong.flow.engine.model.NodeModel;
import com.mldong.flow.engine.model.logicflow.LfNode;
import com.mldong.flow.engine.parser.AbstractNodeParser;

public class ForkParser extends AbstractNodeParser {
    @Override
    public void parseNode(LfNode lfNode) {
    }
    @Override
    public NodeModel newModel() {
        return new ForkModel();
    }
}

parser/impl/JoinParser.java

package com.mldong.flow.engine.parser.impl;
import com.mldong.flow.engine.model.JoinModel;
import com.mldong.flow.engine.model.NodeModel;
import com.mldong.flow.engine.model.logicflow.LfNode;
import com.mldong.flow.engine.parser.AbstractNodeParser;

public class JoinParser extends AbstractNodeParser {
    @Override
    public void parseNode(LfNode lfNode) {
    }
    @Override
    public NodeModel newModel() {
        return new JoinModel();
    }
}

parser/impl/DecisionParser.java

package com.mldong.flow.engine.parser.impl;
import cn.hutool.core.lang.Dict;
import com.mldong.flow.engine.model.DecisionModel;
import com.mldong.flow.engine.model.NodeModel;
import com.mldong.flow.engine.model.logicflow.LfNode;
import com.mldong.flow.engine.parser.AbstractNodeParser;

public class DecisionParser extends AbstractNodeParser {
    
    @Override
    public void parseNode(LfNode lfNode) {
        DecisionModel decisionModel = (DecisionModel) nodeModel;
        Dict properties = lfNode.getProperties();
        decisionModel.setExpr(properties.getStr(EXPR_KEY));
        decisionModel.setHandleClass(properties.getStr(HANDLE_CLASS_KEY));
    }
    @Override
    public NodeModel newModel() {
        return new DecisionModel();
    }
}

服务上下文相关类

Context.java

package com.mldong.flow.engine;
import java.util.List;

public interface Context {
    
    void put(String name, Object object);
    
    void put(String name, Class&lt;?&gt; clazz);
    
    boolean exist(String name);
    
    &lt;T&gt; T find(Class&lt;T&gt; clazz);
    
    &lt;T&gt; List&lt;T&gt; findList(Class&lt;T&gt; clazz);
    
    &lt;T&gt; T findByName(String name, Class&lt;T&gt; clazz);
}

impl/SimpleContext.java

package com.mldong.flow.engine.impl;
import cn.hutool.core.lang.Dict;
import cn.hutool.core.util.ObjectUtil;
import cn.hutool.core.util.ReflectUtil;
import com.mldong.flow.engine.Context;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class SimpleContext implements Context {
    private Dict dict = Dict.create();
    @Override
    public void put(String name, Object object) {
        dict.put(name, object);
    }
    @Override
    public void put(String name, Class&lt;?&gt; clazz) {
        dict.put(name, ReflectUtil.newInstance(clazz));
    }
    @Override
    public boolean exist(String name) {
        return ObjectUtil.isNotNull(dict.getObj(name));
    }
    @Override
    public &lt;T&gt; T find(Class&lt;T&gt; clazz) {
        for (Map.Entry&lt;String, Object&gt; entry : dict.entrySet()) {
            if (clazz.isInstance(entry.getValue())) {
                return clazz.cast(entry.getValue());
            }
        }
        return null;
    }
    @Override
    public &lt;T&gt; List&lt;T&gt; findList(Class&lt;T&gt; clazz) {
        List&lt;T&gt; res = new ArrayList&lt;&gt;();
        for (Map.Entry&lt;String, Object&gt; entry : dict.entrySet()) {
            if (clazz.isInstance(entry.getValue())) {
                res.add(clazz.cast(entry.getValue()));
            }
        }
        return res;
    }
    @Override
    public &lt;T&gt; T findByName(String name, Class&lt;T&gt; clazz) {
        for (Map.Entry&lt;String, Object&gt; entry : dict.entrySet()) {
            if (entry.geTKEy().equals(name) &amp;&amp; clazz.isInstance(entry.getValue())) {
                return clazz.cast(entry.getValue());
            }
        }
        return null;
    }
}

core/ServiceContext.java

package com.mldong.flow.engine.core;
import cn.hutool.core.lang.Assert;
import cn.hutool.core.util.ReflectUtil;
import com.mldong.flow.engine.Context;
import java.util.List;

public class ServiceContext {
    private static Context context;
    public static void setContext(Context context) {
        ServiceContext.context = context;
    }
    public static void put(String name, Object object) {
        Assert.notNull(context,"未注册服务上下文");
        context.put(name, object);
    }
    public static void put(String name, Class&lt;?&gt; clazz) {
        Assert.notNull(context,"未注册服务上下文");
        context.put(name, ReflectUtil.newInstance(clazz));
    }
    public static boolean exist(String name) {
        Assert.notNull(context,"未注册服务上下文");
        return context.exist(name);
    }
    public static &lt;T&gt; T find(Class&lt;T&gt; clazz) {
        Assert.notNull(context,"未注册服务上下文");
        return context.find(clazz);
    }
    public static &lt;T&gt; List&lt;T&gt; findList(Class&lt;T&gt; clazz) {
        Assert.notNull(context,"未注册服务上下文");
        return context.findList(clazz);
    }
    public static &lt;T&gt; T findByName(String name, Class&lt;T&gt; clazz) {
        Assert.notNull(context,"未注册服务上下文");
        return context.findByName(name, clazz);
    }
}

解析入口类

parser/ModelParser.java

package com.mldong.flow.engine.parser;
import cn.hutool.core.collection.CollectionUtil;
import cn.hutool.core.io.IoUtil;
import cn.hutool.json.JSONUtil;
import com.mldong.flow.engine.core.ServiceContext;
import com.mldong.flow.engine.model.NodeModel;
import com.mldong.flow.engine.model.ProceSSModel;
import com.mldong.flow.engine.model.TaskModel;
import com.mldong.flow.engine.model.TransitionModel;
import com.mldong.flow.engine.model.logicflow.LfEdge;
import com.mldong.flow.engine.model.logicflow.LfModel;
import com.mldong.flow.engine.model.logicflow.LfNode;
import java.io.ByteArrayInputStream;
import java.util.List;
public class ModelParser {
    private ModelParser(){}
    
    public static ProcessModel parse(byte [] bytes) {
        String json = IoUtil.readUtf8(new ByteArrayInputStream(bytes));
        LfModel lfModel = JSONUtil.parse(json).toBean(LfModel.class);
        ProcessModel processModel = new ProcessModel();
        List<LfNode> nodes = lfModel.getNodes();
        List<LfEdge> edges = lfModel.getEdges();
        if(CollectionUtil.isEmpty(nodes) || CollectionUtil.isEmpty(edges) )  {
            return processModel;
        }
        // 流程定义基本信息
        processModel.setName(lfModel.getName());
        processModel.setDisplayName(lfModel.getDisplayName());
        processModel.setType(lfModel.getType());
        processModel.setInstanceUrl(lfModel.getInstanceUrl());
        processModel.setInstanceNoClass(lfModel.getInstanceNoClass());
        // 流程节点信息
        nodes.forEach(node->{
            String type = node.getType().replace(NodeParser.NODE_NAME_PREFIX,"");
            NodeParser nodeParser = ServiceContext.findByName(type,NodeParser.class);
            if(nodeParser!=null) {
                nodeParser.parse(node, edges);
                NodeModel nodeModel = nodeParser.getModel();
                processModel.getNodes().add(nodeParser.getModel());
                if (nodeModel instanceof TaskModel) {
                    processModel.getTasks().add((TaskModel) nodeModel);
                }
            }
        });
        // 循环节点模型，构造输入边、输出边的source、target
        for(NodeModel node : processModel.getNodes()) {
            for(TransitionModel transition : node.getOutputs()) {
                String to = transition.getTo();
                for(NodeModel node2 : processModel.getNodes()) {
                    if(to.equalsIgnoreCase(node2.getName())) {
                        node2.getInputs().add(transition);
                        transition.setTarget(node2);
                    }
                }
            }
        }
        return processModel;
    }
}

配置类

cfg/Configuration.java

package com.mldong.flow.engine.cfg;
import com.mldong.flow.engine.Context;
import com.mldong.flow.engine.core.ServiceContext;
import com.mldong.flow.engine.impl.SimpleContext;
import com.mldong.flow.engine.parser.impl.*;
public class Configuration {
    public Configuration() {
        this(new SimpleContext());
    }
    public Configuration(Context context) {
        ServiceContext.setContext(context);
        ServiceContext.put("decision", DecisionParser.class);
        ServiceContext.put("end", EndParser.class);
        ServiceContext.put("fork", ForkParser.class);
        ServiceContext.put("join", JoinParser.class);
        ServiceContext.put("start", StartParser.class);
        ServiceContext.put("task", TaskParser.class);
    }
}

单元测试类

ModelParserTest.java

package com.mldong.flow;
import cn.hutool.core.io.IoUtil;
import cn.hutool.core.lang.Dict;
import com.mldong.flow.engine.cfg.Configuration;
import com.mldong.flow.engine.core.Execution;
import com.mldong.flow.engine.model.ProcessModel;
import com.mldong.flow.engine.parser.ModelParser;
import org.junit.Test;

public class ModelParserTest {
    @Test
    public void parseTest() {
        new Configuration();
        ProcessModel processModel = ModelParser.parse(IoUtil.readBytes(this.getClass().getResourceAsStream("/leave.json")));
        Execution execution = new Execution();
        execution.setArgs(Dict.create());
        processModel.getStart().execute(execution);
    }
}

运行结果

model:StartModel,name:start,displayName:开始,time:2023-04-26 21:32:40
model:TaskModel,name:apply,displayName:请假申请,time:2023-04-26 21:32:41
model:TaskModel,name:approveDept,displayName:部门领导审批,time:2023-04-26 21:32:42
model:EndModel,name:end,displayName:结束,time:2023-04-26 21:32:42

相关源码 mldong-flow-demo-03

流程设计器 在线体验

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