rest api example plugin added

src/main/java/org/imixs/application/plugin/RestConnectorPlugin.java

@@ -0,0 +1,121 @@
+/*******************************************************************************
+ *  Imixs Workflow 
+ *  Copyright (C) 2001, 2024 Imixs Software Solutions GmbH,  
+ *  http://www.imixs.com
+ *  
+ *  This program is free software; you can redistribute it and/or 
+ *  modify it under the terms of the GNU General Public License 
+ *  as published by the Free Software Foundation; either version 2 
+ *  of the License, or (at your option) any later version.
+ *  
+ *  This program is distributed in the hope that it will be useful, 
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of 
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
+ *  General Public License for more details.
+ *  
+ *  You can receive a copy of the GNU General Public
+ *  License at http://www.gnu.org/licenses/gpl.html
+ *  
+ *  Project: 
+ *  	http://www.imixs.org
+ *  	http://java.net/projects/imixs-workflow
+ *  
+ *  Contributors:  
+ *  	Imixs Software Solutions GmbH - initial API and implementation
+ *  	Ralph Soika - Software Developer
+ *******************************************************************************/
+
+package org.imixs.application.plugin;
+
+import java.io.StringReader;
+import java.util.List;
+import java.util.logging.Logger;
+
+import org.imixs.workflow.ItemCollection;
+import org.imixs.workflow.engine.WorkflowService;
+import org.imixs.workflow.engine.plugins.AbstractPlugin;
+import org.imixs.workflow.exceptions.PluginException;
+
+import jakarta.inject.Inject;
+import jakarta.json.Json;
+import jakarta.json.JsonObject;
+import jakarta.json.JsonReader;
+import jakarta.ws.rs.client.Client;
+import jakarta.ws.rs.client.ClientBuilder;
+import jakarta.ws.rs.client.WebTarget;
+import jakarta.ws.rs.core.Response;
+
+/**
+ * This Plugin demonstrates how to implement a JAX-RS client to call a URL
+ * and extract an element from the JSON response.
+ * <p>
+ * The Plugin can be configured in the BPMN Event
+ * 
+ * <p>
+ * Example api-connector Prompt:
+ * 
+ * <pre>
+ * {@code
+        <api-connector name="GET">
+            <endpoint>https://catfact.ninja/fact/</endpoint>
+            <item>length</item>
+        </api-connector>
+ * }
+ * </pre>
+ * 
+ * @author Ralph Soika
+ * @version 1.0
+ *
+ */
+
+public class RestConnectorPlugin extends AbstractPlugin {
+
+	private static final Logger logger = Logger.getLogger(RestConnectorPlugin.class.getName());
+
+	@Inject
+	private WorkflowService workflowService;
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public ItemCollection run(ItemCollection workitem, ItemCollection event)
+			throws PluginException {
+
+		logger.info("...connecting rest api...");
+
+		// read configuration from event
+		List<ItemCollection> apiDefinitions = workflowService.evalWorkflowResultXML(event, "api-connector",
+				"GET", workitem, false);
+
+		if (apiDefinitions != null) {
+			for (ItemCollection apiDefinition : apiDefinitions) {
+				String endpoint = apiDefinition.getItemValueString("endpoint");
+				String item = apiDefinition.getItemValueString("item");
+
+				// Create a JAX-RS client
+				Client client = ClientBuilder.newClient();
+				WebTarget target = client.target(endpoint);
+				Response response = target.request().get();
+				if (response.getStatus() == 200) {
+					// Parse the JSON response
+					String jsonResponse = response.readEntity(String.class);
+					JsonReader jsonReader = Json.createReader(new StringReader(jsonResponse));
+					JsonObject jsonObject = jsonReader.readObject();
+					String itemValue = jsonObject.getString(item);
+					// Update workitem
+					workitem.setItemValue(item, itemValue);
+					jsonReader.close();
+				} else {
+					throw new PluginException(RestConnectorPlugin.class.getSimpleName(), "API-ERROR",
+							"Failed to fetch data: " + response.getStatus());
+				}
+				response.close();
+				client.close();
+			}
+		}
+
+		return workitem;
+	}
+
+}