Merge pull request #2374 from Activiti/daisuke-2184-json-el-resolver

Handling expressions for json variables

activiti-engine/src/main/java/org/activiti/engine/impl/el/VariableScopeElResolver.java

 /* Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -14,90 +14,117 @@ package org.activiti.engine.impl.el;
 
 import java.beans.FeatureDescriptor;
 import java.util.Iterator;
+import java.util.List;
 
 import javax.el.ELContext;
 import javax.el.ELResolver;
 
 import org.activiti.engine.delegate.VariableScope;
+import org.activiti.engine.impl.context.Context;
 import org.activiti.engine.impl.identity.Authentication;
 import org.activiti.engine.impl.persistence.entity.ExecutionEntity;
 import org.activiti.engine.impl.persistence.entity.TaskEntity;
+import org.activiti.engine.impl.persistence.entity.VariableInstance;
+
+import com.fasterxml.jackson.databind.JsonNode;
 
 /**
- * Implementation of an {@link ELResolver} that resolves expressions with the process variables of a given {@link VariableScope} as context. <br>
- * Also exposes the currently logged in username to be used in expressions (if any)
+ * Implementation of an {@link ELResolver} that resolves expressions with the
+ * process variables of a given {@link VariableScope} as context. <br>
+ * Also exposes the currently logged in username to be used in expressions (if
+ * any)
+ * 
+ * 
  * 
-
-
  */
 public class VariableScopeElResolver extends ELResolver {
 
-  public static final String EXECUTION_KEY = "execution";
-  public static final String TASK_KEY = "task";
-  public static final String LOGGED_IN_USER_KEY = "authenticatedUserId";
-
-  protected VariableScope variableScope;
-
-  public VariableScopeElResolver(VariableScope variableScope) {
-    this.variableScope = variableScope;
-  }
-
-  public Object getValue(ELContext context, Object base, Object property) {
-
-    if (base == null) {
-      String variable = (String) property; // according to javadoc, can only be a String
-
-      if ((EXECUTION_KEY.equals(property) && variableScope instanceof ExecutionEntity) || (TASK_KEY.equals(property) && variableScope instanceof TaskEntity)) {
-        context.setPropertyResolved(true);
-        return variableScope;
-      } else if (EXECUTION_KEY.equals(property) && variableScope instanceof TaskEntity) {
-        context.setPropertyResolved(true);
-        return ((TaskEntity) variableScope).getExecution();
-      } else if (LOGGED_IN_USER_KEY.equals(property)) {
-        context.setPropertyResolved(true);
-        return Authentication.getAuthenticatedUserId();
-      } else {
-        if (variableScope.hasVariable(variable)) {
-          context.setPropertyResolved(true); // if not set, the next elResolver in the CompositeElResolver will be called
-          return variableScope.getVariable(variable);
-        }
-      }
-    }
-
-    // property resolution (eg. bean.value) will be done by the
-    // BeanElResolver (part of the CompositeElResolver)
-    // It will use the bean resolved in this resolver as base.
-
-    return null;
-  }
-
-  public boolean isReadOnly(ELContext context, Object base, Object property) {
-    if (base == null) {
-      String variable = (String) property;
-      return !variableScope.hasVariable(variable);
-    }
-    return true;
-  }
-
-  public void setValue(ELContext context, Object base, Object property, Object value) {
-    if (base == null) {
-      String variable = (String) property;
-      if (variableScope.hasVariable(variable)) {
-        variableScope.setVariable(variable, value);
-      }
-    }
-  }
-
-  public Class<?> getCommonPropertyType(ELContext arg0, Object arg1) {
-    return Object.class;
-  }
-
-  public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext arg0, Object arg1) {
-    return null;
-  }
-
-  public Class<?> getType(ELContext arg0, Object arg1, Object arg2) {
-    return Object.class;
-  }
+	public static final String EXECUTION_KEY = "execution";
+	public static final String TASK_KEY = "task";
+	public static final String LOGGED_IN_USER_KEY = "authenticatedUserId";
+
+	protected VariableScope variableScope;
+
+	public VariableScopeElResolver(VariableScope variableScope) {
+		this.variableScope = variableScope;
+	}
+
+	@Override
+	public Object getValue(ELContext context, Object base, Object property) {
+
+		if (base == null) {
+			String variable = (String) property; // according to javadoc, can
+													// only be a String
+
+			if ((EXECUTION_KEY.equals(property) && variableScope instanceof ExecutionEntity)
+					|| (TASK_KEY.equals(property) && variableScope instanceof TaskEntity)) {
+				context.setPropertyResolved(true);
+				return variableScope;
+			} else if (EXECUTION_KEY.equals(property) && variableScope instanceof TaskEntity) {
+				context.setPropertyResolved(true);
+				return ((TaskEntity) variableScope).getExecution();
+			} else if (LOGGED_IN_USER_KEY.equals(property)) {
+				context.setPropertyResolved(true);
+				return Authentication.getAuthenticatedUserId();
+			} else {
+				if (variableScope.hasVariable(variable)) {
+					context.setPropertyResolved(true); // if not set, the next
+														// elResolver in the
+														// CompositeElResolver
+														// will be called
+					VariableInstance variableInstance = variableScope.getVariableInstance(variable);
+					Object value = variableInstance.getValue();
+					if (("json".equals(variableInstance.getTypeName())
+							|| "longJson".equals(variableInstance.getTypeName())) && (value instanceof JsonNode)
+							&& ((JsonNode) value).isArray()) {
+						return Context.getProcessEngineConfiguration().getObjectMapper().convertValue(value,
+								List.class);
+					} else {
+						return value;
+					}
+				}
+			}
+		}
+
+		// property resolution (eg. bean.value) will be done by the
+		// BeanElResolver (part of the CompositeElResolver)
+		// It will use the bean resolved in this resolver as base.
+
+		return null;
+	}
+
+	@Override
+	public boolean isReadOnly(ELContext context, Object base, Object property) {
+		if (base == null) {
+			String variable = (String) property;
+			return !variableScope.hasVariable(variable);
+		}
+		return true;
+	}
+
+	@Override
+	public void setValue(ELContext context, Object base, Object property, Object value) {
+		if (base == null) {
+			String variable = (String) property;
+			if (variableScope.hasVariable(variable)) {
+				variableScope.setVariable(variable, value);
+			}
+		}
+	}
+
+	@Override
+	public Class<?> getCommonPropertyType(ELContext arg0, Object arg1) {
+		return Object.class;
+	}
+
+	@Override
+	public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext arg0, Object arg1) {
+		return null;
+	}
+
+	@Override
+	public Class<?> getType(ELContext arg0, Object arg1, Object arg2) {
+		return Object.class;
+	}
 
 }

activiti-engine/src/test/java/org/activiti/engine/test/json/SerializePOJOJsonTest.java

+package org.activiti.engine.test.json;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Consumer;
+
+import org.activiti.engine.history.HistoricTaskInstance;
+import org.activiti.engine.impl.test.ResourceActivitiTestCase;
+import org.activiti.engine.runtime.ProcessInstance;
+import org.activiti.engine.task.IdentityLink;
+import org.activiti.engine.task.Task;
+import org.activiti.engine.test.Deployment;
+import org.activiti.examples.variables.SomeSerializable;
+
+public class SerializePOJOJsonTest extends ResourceActivitiTestCase {
+
+    public SerializePOJOJsonTest() {
+        super("org/activiti/standalone/cfg/variable/custom-serialize-variables-activiti.cfg.xml");
+    }
+
+    @Deployment
+    public void testJsonVarInExpression() throws Exception {
+        Map<String, Object> vars = new HashMap<String, Object>();
+        Map<String, Object> map = new HashMap<String, Object>();
+        map.put("assignee", "salaboy");
+        map.put("category", "test");
+        Map<String, Object> mapInMap = new HashMap<String, Object>();
+        mapInMap.put("user", "salaboy");
+        map.put("mapInMap", mapInMap);
+        vars.put("userMap", map);
+        List<String> list = Arrays.asList("salaboy", "salaboy", "salaboy");
+        vars.put("userCollection", list);
+        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("testJsonVarInExpression", vars);
+        String taskId = taskService.createTaskQuery().processInstanceId(processInstance.getId()).singleResult().getId();
+        taskService.complete(taskId);
+        taskId = taskService.createTaskQuery().processInstanceId(processInstance.getId()).singleResult().getId();
+        taskService.getIdentityLinksForTask(taskId).stream().forEach(new Consumer<IdentityLink>() {
+            @Override
+            public void accept(IdentityLink i) {
+                if ("candidate".equals(i.getType()) ) {
+                    assertEquals("salaboy", i.getUserId());
+                }
+            }
+        });
+        taskService.complete(taskId);
+        HistoricTaskInstance task = historyService.createHistoricTaskInstanceQuery().taskId(taskId).singleResult();
+        assertEquals("salaboy", task.getAssignee());
+        assertEquals("test", task.getCategory());
+    }
+
+    @Deployment
+    public void testCollectionJsonVarInExpression() throws Exception {
+        Map<String, Object> vars = new HashMap<String, Object>();
+        List<String> list = Arrays.asList("salaboy", "salaboy", "salaboy");
+        vars.put("userCollection", list);
+        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("testCollectionJsonVarInExpression", vars);
+        String taskId = taskService.createTaskQuery().processInstanceId(processInstance.getId()).singleResult().getId();
+        taskService.complete(taskId);
+        List<Task> tasks = taskService.createTaskQuery().processInstanceId(processInstance.getId()).list();
+        assertEquals(3, tasks.size());
+        tasks.forEach(task -> taskService.complete(task.getId()));
+
+    }
+
+    @Deployment
+    public void testCollectionInJsonVarInExpression() throws Exception {
+        Map<String, Object> vars = new HashMap<String, Object>();
+        List<String> list = Arrays.asList("salaboy", "salaboy", "salaboy");
+        Map<String, Object> map = new HashMap<String, Object>();
+        map.put("userCollection", list);
+        vars.put("userMap", map);
+        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("testCollectionInJsonVarInExpression", vars);
+        String taskId = taskService.createTaskQuery().processInstanceId(processInstance.getId()).singleResult().getId();
+        taskService.complete(taskId);
+        taskService.createTaskQuery().processInstanceId(processInstance.getId()).list().forEach(task -> taskService.complete(task.getId()));
+
+        vars = new HashMap<String, Object>();
+        List<SomeSerializable> beanList = Arrays.asList(new SomeSerializable("salaboy"), new SomeSerializable("salaboy"), new SomeSerializable("salaboy"));
+        map = new HashMap<String, Object>();
+        map.put("userCollection", beanList);
+        vars.put("userMap", map);
+        processInstance = runtimeService.startProcessInstanceByKey("testCollectionInJsonVarInExpression", vars);
+        taskId = taskService.createTaskQuery().processInstanceId(processInstance.getId()).singleResult().getId();
+        taskService.complete(taskId);
+        List<Task> tasks = taskService.createTaskQuery().processInstanceId(processInstance.getId()).list();
+        assertEquals(3, tasks.size());
+        tasks.forEach(task -> taskService.complete(task.getId()));
+    }
+
+    @Deployment
+    public void testPOJOCollectionInJsonVarInExpression() throws Exception {
+        Map<String, Object> vars = new HashMap<String, Object>();
+        Map<String, Object> map = new HashMap<String, Object>();
+        vars = new HashMap<String, Object>();
+        List<SomeSerializable> beanList = Arrays.asList(new SomeSerializable("salaboy"), new SomeSerializable("salaboy"), new SomeSerializable("salaboy"));
+        map = new HashMap<String, Object>();
+        map.put("userCollection", beanList);
+        vars.put("userMap", map);
+        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("testPOJOCollectionInJsonVarInExpression", vars);
+        String taskId = taskService.createTaskQuery().processInstanceId(processInstance.getId()).singleResult().getId();
+        taskService.complete(taskId);
+        List<Task> tasks = taskService.createTaskQuery().processInstanceId(processInstance.getId()).list();
+        assertEquals(3, tasks.size());
+        tasks.forEach(task -> taskService.complete(task.getId()));
+    }
+}
\ No newline at end of file

activiti-engine/src/test/resources/org/activiti/engine/test/json/SerializePOJOJsonTest.testCollectionInJsonVarInExpression.bpmn20.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:activiti="http://activiti.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="Examples">
+  <process id="testCollectionInJsonVarInExpression" name="Test Collection In Json Var In Expression" isExecutable="true">
+    <startEvent id="theStart"></startEvent>
+    <sequenceFlow id="flow1" sourceRef="theStart" targetRef="userTask"></sequenceFlow>
+    <userTask id="userTask"></userTask>
+    <endEvent id="theEndSuccess"></endEvent>
+    <userTask id="usertask1" name="User Task">
+      <multiInstanceLoopCharacteristics isSequential="false" activiti:collection="${userMap.userCollection}"></multiInstanceLoopCharacteristics>
+    </userTask>
+    <sequenceFlow id="flow2" sourceRef="userTask" targetRef="usertask1"></sequenceFlow>
+    <sequenceFlow id="flow3" sourceRef="usertask1" targetRef="theEndSuccess"></sequenceFlow>
+  </process>
+  <bpmndi:BPMNDiagram id="BPMNDiagram_testCollectionInJsonVarInExpression">
+    <bpmndi:BPMNPlane bpmnElement="testCollectionInJsonVarInExpression" id="BPMNPlane_testCollectionInJsonVarInExpression">
+      <bpmndi:BPMNShape bpmnElement="theStart" id="BPMNShape_theStart">
+        <omgdc:Bounds height="35.0" width="35.0" x="70.0" y="95.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="userTask" id="BPMNShape_userTask">
+        <omgdc:Bounds height="60.0" width="100.0" x="170.0" y="83.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="theEndSuccess" id="BPMNShape_theEndSuccess">
+        <omgdc:Bounds height="35.0" width="35.0" x="490.0" y="95.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="usertask1" id="BPMNShape_usertask1">
+        <omgdc:Bounds height="55.0" width="105.0" x="310.0" y="85.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNEdge bpmnElement="flow1" id="BPMNEdge_flow1">
+        <omgdi:waypoint x="105.0" y="112.0"></omgdi:waypoint>
+        <omgdi:waypoint x="170.0" y="113.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge bpmnElement="flow2" id="BPMNEdge_flow2">
+        <omgdi:waypoint x="270.0" y="113.0"></omgdi:waypoint>
+        <omgdi:waypoint x="310.0" y="112.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge bpmnElement="flow3" id="BPMNEdge_flow3">
+        <omgdi:waypoint x="415.0" y="112.0"></omgdi:waypoint>
+        <omgdi:waypoint x="490.0" y="112.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+    </bpmndi:BPMNPlane>
+  </bpmndi:BPMNDiagram>
+</definitions>
\ No newline at end of file

activiti-engine/src/test/resources/org/activiti/engine/test/json/SerializePOJOJsonTest.testCollectionJsonVarInExpression.bpmn20.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:activiti="http://activiti.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="Examples">
+  <process id="testCollectionJsonVarInExpression" name="Test Collection Json Var In Expression" isExecutable="true">
+    <startEvent id="theStart"></startEvent>
+    <sequenceFlow id="flow1" sourceRef="theStart" targetRef="userTask"></sequenceFlow>
+    <userTask id="userTask"></userTask>
+    <endEvent id="theEndSuccess"></endEvent>
+    <userTask id="usertask1" name="User Task">
+      <multiInstanceLoopCharacteristics isSequential="false" activiti:collection="${userCollection}"></multiInstanceLoopCharacteristics>
+    </userTask>
+    <sequenceFlow id="flow2" sourceRef="userTask" targetRef="usertask1"></sequenceFlow>
+    <sequenceFlow id="flow3" sourceRef="usertask1" targetRef="theEndSuccess"></sequenceFlow>
+  </process>
+  <bpmndi:BPMNDiagram id="BPMNDiagram_testCollectionJsonVarInExpression">
+    <bpmndi:BPMNPlane bpmnElement="testCollectionJsonVarInExpression" id="BPMNPlane_testCollectionJsonVarInExpression">
+      <bpmndi:BPMNShape bpmnElement="theStart" id="BPMNShape_theStart">
+        <omgdc:Bounds height="35.0" width="35.0" x="70.0" y="95.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="userTask" id="BPMNShape_userTask">
+        <omgdc:Bounds height="60.0" width="100.0" x="170.0" y="83.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="theEndSuccess" id="BPMNShape_theEndSuccess">
+        <omgdc:Bounds height="35.0" width="35.0" x="490.0" y="95.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="usertask1" id="BPMNShape_usertask1">
+        <omgdc:Bounds height="55.0" width="105.0" x="310.0" y="85.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNEdge bpmnElement="flow1" id="BPMNEdge_flow1">
+        <omgdi:waypoint x="105.0" y="112.0"></omgdi:waypoint>
+        <omgdi:waypoint x="170.0" y="113.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge bpmnElement="flow2" id="BPMNEdge_flow2">
+        <omgdi:waypoint x="270.0" y="113.0"></omgdi:waypoint>
+        <omgdi:waypoint x="310.0" y="112.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge bpmnElement="flow3" id="BPMNEdge_flow3">
+        <omgdi:waypoint x="415.0" y="112.0"></omgdi:waypoint>
+        <omgdi:waypoint x="490.0" y="112.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+    </bpmndi:BPMNPlane>
+  </bpmndi:BPMNDiagram>
+</definitions>
\ No newline at end of file

activiti-engine/src/test/resources/org/activiti/engine/test/json/SerializePOJOJsonTest.testJsonVarInExpression.bpmn20.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:activiti="http://activiti.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="Examples">
+  <process id="testJsonVarInExpression" name="Test Json Var In Expression" isExecutable="true">
+    <startEvent id="theStart"></startEvent>
+    <sequenceFlow id="flow1" sourceRef="theStart" targetRef="userTask"></sequenceFlow>
+    <userTask id="userTask"></userTask>
+    <endEvent id="theEndSuccess"></endEvent>
+    <userTask id="usertask1" name="User Task" activiti:assignee="${userMap.assignee}" activiti:candidateUsers="${userMap.mapInMap.user}" activiti:category="${userMap.category}"></userTask>
+    <sequenceFlow id="flow2" sourceRef="userTask" targetRef="usertask1"></sequenceFlow>
+    <sequenceFlow id="flow3" sourceRef="usertask1" targetRef="theEndSuccess"></sequenceFlow>
+  </process>
+  <bpmndi:BPMNDiagram id="BPMNDiagram_testJsonVarInExpression">
+    <bpmndi:BPMNPlane bpmnElement="testJsonVarInExpression" id="BPMNPlane_testJsonVarInExpression">
+      <bpmndi:BPMNShape bpmnElement="theStart" id="BPMNShape_theStart">
+        <omgdc:Bounds height="35.0" width="35.0" x="70.0" y="95.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="userTask" id="BPMNShape_userTask">
+        <omgdc:Bounds height="60.0" width="100.0" x="170.0" y="83.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="theEndSuccess" id="BPMNShape_theEndSuccess">
+        <omgdc:Bounds height="35.0" width="35.0" x="490.0" y="95.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="usertask1" id="BPMNShape_usertask1">
+        <omgdc:Bounds height="55.0" width="105.0" x="310.0" y="85.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNEdge bpmnElement="flow1" id="BPMNEdge_flow1">
+        <omgdi:waypoint x="105.0" y="112.0"></omgdi:waypoint>
+        <omgdi:waypoint x="170.0" y="113.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge bpmnElement="flow2" id="BPMNEdge_flow2">
+        <omgdi:waypoint x="270.0" y="113.0"></omgdi:waypoint>
+        <omgdi:waypoint x="310.0" y="112.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge bpmnElement="flow3" id="BPMNEdge_flow3">
+        <omgdi:waypoint x="415.0" y="112.0"></omgdi:waypoint>
+        <omgdi:waypoint x="490.0" y="112.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+    </bpmndi:BPMNPlane>
+  </bpmndi:BPMNDiagram>
+</definitions>
\ No newline at end of file

activiti-engine/src/test/resources/org/activiti/engine/test/json/SerializePOJOJsonTest.testPOJOCollectionInJsonVarInExpression.bpmn20.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:activiti="http://activiti.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="Examples">
+  <process id="testPOJOCollectionInJsonVarInExpression" name="Test POJO Collection In Json Var In Expression" isExecutable="true">
+    <startEvent id="theStart"></startEvent>
+    <sequenceFlow id="flow1" sourceRef="theStart" targetRef="userTask"></sequenceFlow>
+    <userTask id="userTask"></userTask>
+    <endEvent id="theEndSuccess"></endEvent>
+    <userTask id="usertask1" name="User Task" activiti:assignee="${userMap.userCollection.get(0).value}">
+      <multiInstanceLoopCharacteristics isSequential="false" activiti:collection="${userMap.userCollection}"></multiInstanceLoopCharacteristics>
+    </userTask>
+    <sequenceFlow id="flow2" sourceRef="userTask" targetRef="usertask1"></sequenceFlow>
+    <sequenceFlow id="flow3" sourceRef="usertask1" targetRef="theEndSuccess"></sequenceFlow>
+  </process>
+  <bpmndi:BPMNDiagram id="BPMNDiagram_testPOJOCollectionInJsonVarInExpression">
+    <bpmndi:BPMNPlane bpmnElement="testPOJOCollectionInJsonVarInExpression" id="BPMNPlane_testPOJOCollectionInJsonVarInExpression">
+      <bpmndi:BPMNShape bpmnElement="theStart" id="BPMNShape_theStart">
+        <omgdc:Bounds height="35.0" width="35.0" x="70.0" y="95.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="userTask" id="BPMNShape_userTask">
+        <omgdc:Bounds height="60.0" width="100.0" x="170.0" y="83.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="theEndSuccess" id="BPMNShape_theEndSuccess">
+        <omgdc:Bounds height="35.0" width="35.0" x="490.0" y="95.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape bpmnElement="usertask1" id="BPMNShape_usertask1">
+        <omgdc:Bounds height="55.0" width="105.0" x="310.0" y="85.0"></omgdc:Bounds>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNEdge bpmnElement="flow1" id="BPMNEdge_flow1">
+        <omgdi:waypoint x="105.0" y="112.0"></omgdi:waypoint>
+        <omgdi:waypoint x="170.0" y="113.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge bpmnElement="flow2" id="BPMNEdge_flow2">
+        <omgdi:waypoint x="270.0" y="113.0"></omgdi:waypoint>
+        <omgdi:waypoint x="310.0" y="112.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge bpmnElement="flow3" id="BPMNEdge_flow3">
+        <omgdi:waypoint x="415.0" y="112.0"></omgdi:waypoint>
+        <omgdi:waypoint x="490.0" y="112.0"></omgdi:waypoint>
+      </bpmndi:BPMNEdge>
+    </bpmndi:BPMNPlane>
+  </bpmndi:BPMNDiagram>
+</definitions>
\ No newline at end of file

activiti-engine/src/test/resources/org/activiti/standalone/cfg/variable/custom-serialize-variables-activiti.cfg.xml

+<?xml version="1.0" encoding="UTF-8"?>
+
+<beans xmlns="http://www.springframework.org/schema/beans"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://www.springframework.org/schema/beans   http://www.springframework.org/schema/beans/spring-beans.xsd">
+
+  <bean id="processEngineConfiguration" class="org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration">
+
+    <property name="jdbcUrl" value="jdbc:h2:mem:activiti;DB_CLOSE_DELAY=1000;MVCC=TRUE" />
+    <property name="jdbcDriver" value="org.h2.Driver" />
+    <property name="jdbcUsername" value="sa" />
+    <property name="jdbcPassword" value="" />
+    
+    <!-- Database configurations -->
+    <property name="databaseSchemaUpdate" value="drop-create" />
+
+	<!-- Test logger -->
+	<!-- <property name="configurators">
+		<list>
+			<bean class="org.activiti.engine.test.impl.logger.ProcessExecutionLoggerConfigurator" />
+		</list>
+	</property> -->
+
+    <!-- job executor configurations -->
+    <property name="asyncExecutor" ref="asyncExecutor" />
+    <property name="asyncExecutorActivate" value="true" />
+    
+    <property name="asyncFailedJobWaitTime" value="1" />
+
+    <!-- mail server configurations -->
+    <property name="mailServerPort" value="5025" />
+    
+    <property name="mailServers">
+      <map>
+        <entry key="myEmailTenant">
+          <bean class="org.activiti.engine.cfg.MailServerInfo">
+            <property name="mailServerHost" value="localhost" />
+            <property name="mailServerPort" value="5025" />
+            <property name="mailServerUseSSL" value="false" />
+            <property name="mailServerUseTLS" value="false" />
+            <property name="mailServerDefaultFrom" value="activiti@myTenant.com" />
+            <property name="mailServerUsername" value="activiti@myTenant.com" />
+            <property name="mailServerPassword" value="password" />
+          </bean>
+        </entry>
+      </map>
+    </property>
+    
+    <property name="history" value="full" />
+    
+    <property name="enableProcessDefinitionInfoCache" value="true" />
+    <property name="serializePOJOsInVariablesToJson" value="true" />
+  </bean>
+  
+  <bean id="asyncExecutor" class="org.activiti.engine.impl.asyncexecutor.DefaultAsyncJobExecutor">
+    <property name="defaultAsyncJobAcquireWaitTimeInMillis" value="1000" />
+    <property name="defaultTimerJobAcquireWaitTimeInMillis" value="1000" />
+  </bean>
+
+</beans>
\ No newline at end of file