Merge pull request #17 from TIHBS/start-plguins-option-on-start

Optional boolean flag to enable plugins at start

Author: akshay-ap

README.md

@@ -73,9 +73,10 @@ mvn install
 Then, the WAR file (which can be found in the folder 'target' generated after a successful build) can be deployed on an
 Apache Tomcat server.
 
-Required VM options while running
+VM options while running
 
-- `pf4j.pluginsDir` path where the plugins will be stored
+- `pf4j.pluginsDir` path where the plugins will be stored. This property is mandatory.
+- `enablePluginsAtStart` boolean flag to enable plugins during startup (default false). This property is optional.
 
 ## Plugin management
 

pom.xml

@@ -50,6 +50,11 @@
     </dependencyManagement>
 
     <dependencies>
+        <dependency>
+            <groupId>org.glassfish</groupId>
+            <artifactId>javax.json</artifactId>
+            <version>1.0.4</version>
+        </dependency>
         <dependency>
             <groupId>org.glassfish.jersey.containers</groupId>
             <artifactId>jersey-container-servlet-core</artifactId>

src/main/java/blockchains/iaas/uni/stuttgart/de/management/BlockchainPluginManager.java

@@ -16,13 +16,25 @@
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.jsontype.NamedType;
-import org.pf4j.*;
+import org.pf4j.DefaultPluginManager;
+import org.pf4j.PluginManager;
+import org.pf4j.PluginState;
+import org.pf4j.PluginWrapper;
+import org.pf4j.ManifestPluginDescriptorFinder;
+import org.pf4j.DependencyResolver.DependenciesNotFoundException;
+import org.pf4j.JarPluginLoader;
+import org.pf4j.PluginDescriptorFinder;
+import org.pf4j.PluginLoader;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.nio.file.Path;
 import java.util.List;
 
 public class BlockchainPluginManager {
 
+    private static final Logger log = LoggerFactory.getLogger(BlockchainPluginManager.class);
+
     private PluginManager pluginManager = null;
     private static BlockchainPluginManager instance = null;
 
@@ -41,8 +53,12 @@ protected PluginDescriptorFinder createPluginDescriptorFinder() {
                 return new ManifestPluginDescriptorFinder();
             }
         };
+
         pluginManager.loadPlugins();
 
+        if (Boolean.getBoolean("enablePluginsAtStart")) {
+            pluginManager.startPlugins();
+        }
     }
 
     public static BlockchainPluginManager getInstance() {

src/main/java/blockchains/iaas/uni/stuttgart/de/restapi/Controllers/PluginManagerController.java

@@ -6,6 +6,7 @@
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import org.glassfish.jersey.media.multipart.FormDataContentDisposition;
 import org.glassfish.jersey.media.multipart.FormDataParam;
+import org.pf4j.DependencyResolver.DependenciesNotFoundException;
 import org.pf4j.PluginWrapper;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -47,10 +48,12 @@ public Response uploadJar(@FormDataParam("file") InputStream uploadedInputStream
             return Response.status(Response.Status.BAD_REQUEST).entity("File already exists with same name.").build();
         }
         writeToFile(uploadedInputStream, uploadedFileLocation);
-
-        blockchainPluginManager.loadJar(filePath);
-
-        return Response.ok().build();
+        try {
+            blockchainPluginManager.loadJar(filePath);
+            return Response.ok().build();
+        } catch (DependenciesNotFoundException e) {
+            return Response.status(400).entity(e.getMessage()).type("text/plain").build();
+        }
     }
 
     @POST