Use ApplicationStartupEvent to connect to Woken and fill the local db

src/main/java/eu/hbp/mip/StartupTasks.java

+package eu.hbp.mip;
+
+import eu.hbp.mip.controllers.DatasetsApi;
+import eu.hbp.mip.model.Variable;
+import eu.hbp.mip.repositories.VariableRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.context.ApplicationListener;
+import org.springframework.stereotype.Component;
+
+@Component
+public class StartupTasks implements ApplicationListener<ApplicationReadyEvent> {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(StartupTasks.class);
+
+    @Autowired
+    private VariableRepository variableRepository;
+
+    @Autowired
+    private DatasetsApi datasetsApi;
+
+    @Override
+    public void onApplicationEvent(ApplicationReadyEvent event) {
+        // Pre-fill the local variable repository with the list of datasets, interpreted here as variables
+        // (a bit like a categorical variable can be split into a set of variables (a.k.a one hot encoding in Data science) )
+        try {
+            for (ch.chuv.lren.woken.messages.datasets.Dataset dataset: datasetsApi.fetchDatasets()) {
+                final String code = dataset.dataset().code();
+                Variable v = variableRepository.findOne(code);
+                if (v == null) {
+                    v = new Variable(code);
+                    variableRepository.save(v);
+                }
+            }
+        } catch (Exception e) {
+            LOGGER.error("Cannot initialise the variable repository. Is the connection to Woken working?", e);
+        }
+
+        LOGGER.info("MIP Portal backend is ready!");
+    }
+}

src/main/java/eu/hbp/mip/controllers/DatasetsApi.java

@@ -7,17 +7,13 @@ package eu.hbp.mip.controllers;
 
 import ch.chuv.lren.woken.messages.datasets.DatasetsQuery;
 import ch.chuv.lren.woken.messages.datasets.DatasetsResponse;
-import com.google.gson.Gson;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonObject;
 import eu.hbp.mip.akka.WokenClientController;
 import eu.hbp.mip.model.Dataset;
-import eu.hbp.mip.model.Variable;
-import eu.hbp.mip.repositories.VariableRepository;
 import io.swagger.annotations.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -25,10 +21,7 @@ import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 import scala.Option;
 
-import javax.annotation.PostConstruct;
-
 import java.util.Set;
-import java.util.stream.Stream;
 
 import static org.springframework.http.MediaType.APPLICATION_JSON_VALUE;
 
@@ -39,24 +32,6 @@ import static org.springframework.http.MediaType.APPLICATION_JSON_VALUE;
 public class DatasetsApi extends WokenClientController {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(DatasetsApi.class);
-    private static final Gson gson = new Gson();
-
-    @Autowired
-    private VariableRepository variableRepository;
-
-    @PostConstruct
-    public void init() throws Exception {
-        // Pre-fill the local variable repository with the list of datasets, interpreted here as variables
-        // (a bit like a categorical variable can be split into a set of variables (a.k.a one hot encoding in Data science) )
-        for (ch.chuv.lren.woken.messages.datasets.Dataset dataset: fetchDatasets()) {
-            final String code = dataset.dataset().code();
-            Variable v = variableRepository.findOne(code);
-            if (v == null) {
-                v = new Variable(code);
-                variableRepository.save(v);
-            }
-        }
-    }
 
     @ApiOperation(value = "Get dataset list", response = Dataset.class, responseContainer = "List")
     @RequestMapping(method = RequestMethod.GET)
@@ -66,7 +41,7 @@ public class DatasetsApi extends WokenClientController {
 
         try {
             JsonArray datasets = new JsonArray();
-            Stream<JsonObject> values = fetchDatasets().stream().map(d -> {
+            fetchDatasets().stream().map(d -> {
                 JsonObject jsObject = new JsonObject();
                 jsObject.addProperty("code", d.dataset().code());
                 jsObject.addProperty("label", d.label());
@@ -83,7 +58,7 @@ public class DatasetsApi extends WokenClientController {
 
     }
 
-    private Set<ch.chuv.lren.woken.messages.datasets.Dataset> fetchDatasets() throws Exception {
+    public Set<ch.chuv.lren.woken.messages.datasets.Dataset> fetchDatasets() throws Exception {
         DatasetsResponse result = askWoken(new DatasetsQuery(Option.empty()), 30);
         return scala.collection.JavaConversions.setAsJavaSet(result.datasets());
     }