Allow JsonNodeELResolver to invoke methods

modules/flowable-engine-common/src/main/java/org/flowable/common/engine/impl/el/JsonNodeELResolver.java

@@ -14,9 +14,11 @@
 
 import java.beans.FeatureDescriptor;
 import java.math.BigDecimal;
+import java.util.Arrays;
 import java.util.Date;
 import java.util.Iterator;
 
+import org.flowable.common.engine.impl.javax.el.BeanELResolver;
 import org.flowable.common.engine.impl.javax.el.CompositeELResolver;
 import org.flowable.common.engine.impl.javax.el.ELContext;
 import org.flowable.common.engine.impl.javax.el.ELException;
@@ -37,19 +39,21 @@
 public class JsonNodeELResolver extends ELResolver {
 
     private final boolean readOnly;
+    private final BeanELResolver beanELResolver;
 
     /**
-     * Creates a new read/write BeanELResolver.
+     * Creates a new read/write JsonNodeELResolver.
      */
     public JsonNodeELResolver() {
         this(false);
     }
 
     /**
-     * Creates a new BeanELResolver whose read-only status is determined by the given parameter.
+     * Creates a new JsonNodeELResolver whose read-only status is determined by the given parameter.
      */
     public JsonNodeELResolver(boolean readOnly) {
         this.readOnly = readOnly;
+        this.beanELResolver = new BeanELResolver(readOnly);
     }
 
     /**
@@ -257,6 +261,36 @@ public boolean isReadOnly(ELContext context, Object base, Object property) {
         }
         return readOnly;
     }
+
+    @Override
+	public Object invoke(ELContext context, Object base, Object method, Class<?>[] paramTypes, Object[] params) {
+        if (context == null) {
+            throw new NullPointerException("context is null");
+        }
+
+        Object result = null;
+        if (isResolvable(base)) {
+            // Use BeanELResolver to invoke the method.
+            // If a JsonNode method has a number as a parameter (e.g. an index) it is always an int (with the exception of methods like asLong, asDouble etc.).
+            // In JUEL expressions, literal numbers are treated as Long. Therefore, we are converting them to int here.
+            Object[] convertedParams;
+            if (params == null || method.toString().startsWith("as")) {
+                convertedParams = params;
+            } else {
+                convertedParams = Arrays.asList(params).stream().<Object>map(param -> {
+                    if (param instanceof Number) {
+                        return ((Number) param).intValue();
+                    } else {
+                        return param;
+                    }
+                }).toArray();
+            }
+            result = beanELResolver.invoke(context, base, method, paramTypes, convertedParams);
+            context.setPropertyResolved(true);
+        }
+
+        return result;
+	}
 
     /**
      * If the base object is a map, attempts to set the value associated with the given key, as specified by the property argument. If the base is a Map, the propertyResolved property of the ELContext

modules/flowable-engine/src/test/java/org/flowable/engine/test/el/ExpressionManagerTest.java

@@ -15,6 +15,7 @@
 
 import static net.javacrumbs.jsonunit.assertj.JsonAssertions.assertThatJson;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -32,6 +33,7 @@
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 
+import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
 
 /**
@@ -275,6 +277,60 @@ public void testInvokeIntegerMethodWithNullParameter() {
         assertThat(value).isNull();
     }
 
+    @Test
+    @Deployment(resources = "org/flowable/engine/test/api/runtime/oneTaskProcess.bpmn20.xml")
+    public void testInvokeOnArrayNode() {
+        Map<String, Object> vars = new HashMap<>();
+        ArrayNode arrayNode = processEngineConfiguration.getObjectMapper().createArrayNode();
+        arrayNode.add("firstValue");
+        arrayNode.add("secondValue");
+        arrayNode.add(42);
+
+        vars.put("array", arrayNode);
+        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("oneTaskProcess", vars);
+
+        assertEquals(getExpressionValue("${array.get(0).isTextual()}", processInstance), true);
+        assertEquals(getExpressionValue("${array.get(0).textValue()}", processInstance), "firstValue");
+        assertEquals(getExpressionValue("${array.get(0).isNumber()}", processInstance), false);
+
+        assertEquals(getExpressionValue("${array.get(2).isNumber()}", processInstance), true);
+        assertEquals(getExpressionValue("${array.get(2).asInt()}", processInstance), 42);
+        assertEquals(getExpressionValue("${array.get(2).asLong()}", processInstance), 42L);
+
+        assertEquals(getExpressionValue("${array.get(1).textValue()}", processInstance), "secondValue");
+        assertEquals(getExpressionValue("${array.get(1).asLong(123)}", processInstance), 123L);
+    }
+
+    @Test
+    @Deployment(resources = "org/flowable/engine/test/api/runtime/oneTaskProcess.bpmn20.xml")
+    public void testInvokeOnObjectNode() {
+        Map<String, Object> vars = new HashMap<>();
+        ObjectNode objectNode = processEngineConfiguration.getObjectMapper().createObjectNode();
+        objectNode.put("firstAttribute", "foo");
+        objectNode.put("secondAttribute", "bar");
+        objectNode.put("thirdAttribute", 42);
+
+        vars.put("object", objectNode);
+        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("oneTaskProcess", vars);
+
+        assertEquals(getExpressionValue("${object.get(\"firstAttribute\").isTextual()}", processInstance), true);
+        assertEquals(getExpressionValue("${object.get(\"firstAttribute\").textValue()}", processInstance), "foo");
+        assertEquals(getExpressionValue("${object.get(\"firstAttribute\").isNumber()}", processInstance), false);
+
+        assertEquals(getExpressionValue("${object.get(\"thirdAttribute\").isNumber()}", processInstance), true);
+        assertEquals(getExpressionValue("${object.get(\"thirdAttribute\").asInt()}", processInstance), 42);
+        assertEquals(getExpressionValue("${object.get(\"thirdAttribute\").asLong()}", processInstance), 42L);
+
+        assertEquals(getExpressionValue("${object.get(\"secondAttribute\").textValue()}", processInstance), "bar");
+        assertEquals(getExpressionValue("${object.get(\"secondAttribute\").asLong(123)}", processInstance), 123L);
+    }
+
+    private Object getExpressionValue(String expressionStr, ProcessInstance processInstance) {
+        Expression expression = this.processEngineConfiguration.getExpressionManager().createExpression(expressionStr);
+        return managementService.executeCommand(commandContext ->
+            expression.getValue((ExecutionEntity) runtimeService.createProcessInstanceQuery().processInstanceId(processInstance.getId()).includeProcessVariables().singleResult()));
+    }
+
     @ParameterizedTest
     @Deployment(resources = "org/flowable/engine/test/api/runtime/oneTaskProcess.bpmn20.xml")
     @ValueSource(strings = { "", "flowable" })