add impl to delete unfinished tasks (#741)

this should be used with care though: if an unfinished task (i.e. the response did not arrive yet) is deleted
prematurely and the response actually would arrive later, we would not know what to do about/with it.

so, use "Delete Unfinished" only if you are sure that these tasks are just zombies.

Author: goekay

src/main/java/de/rwth/idsg/steve/repository/TaskStore.java

@@ -32,4 +32,5 @@ public interface TaskStore {
     CommunicationTask get(Integer taskId);
     Integer add(CommunicationTask task);
     void clearFinished();
+    void clearUnfinished();
 }

src/main/java/de/rwth/idsg/steve/repository/impl/TaskStoreImpl.java

@@ -26,8 +26,10 @@
 import org.springframework.stereotype.Repository;
 
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
 /**
@@ -79,9 +81,18 @@ public Integer add(CommunicationTask task) {
 
     @Override
     public void clearFinished() {
+        removeTasks(entry -> entry.getValue().isFinished());
+    }
+
+    @Override
+    public void clearUnfinished() {
+        removeTasks(entry -> !entry.getValue().isFinished());
+    }
+
+    private void removeTasks(Predicate<Map.Entry<Integer, CommunicationTask>> filterPredicate) {
         lookupTable.entrySet()
                    .stream()
-                   .filter(entry -> entry.getValue().isFinished())
+                   .filter(filterPredicate)
                    .forEach(entry -> lookupTable.remove(entry.getKey()));
     }
 }

src/main/java/de/rwth/idsg/steve/web/controller/TaskController.java

@@ -59,12 +59,18 @@ public String getOverview(Model model) {
         return "tasks";
     }
 
-    @RequestMapping(method = RequestMethod.POST)
+    @RequestMapping(params = "finished", method = RequestMethod.POST)
     public String clearFinished(Model model) {
         taskStore.clearFinished();
         return getOverview(model);
     }
 
+    @RequestMapping(params = "unfinished", method = RequestMethod.POST)
+    public String clearUnfinished(Model model) {
+        taskStore.clearUnfinished();
+        return getOverview(model);
+    }
+
     @RequestMapping(value = TASK_ID_PATH, method = RequestMethod.GET)
     public String getTaskDetails(@PathVariable("taskId") Integer taskId, Model model) {
         CommunicationTask r = taskStore.get(taskId);

src/main/resources/webapp/WEB-INF/views/tasks.jsp

@@ -29,7 +29,8 @@
         Request Tasks <a class="tooltip" href="#"><img src="${ctxPath}/static/images/info.png" style="vertical-align:middle"><span>Click on Task IDs for detailed task information.</span></a>
     </span></section>
     <form:form action="${ctxPath}/manager/operations/tasks">
-        <input type="submit" value="Delete Finished"/>
+        <input type="submit" name="finished" value="Delete Finished"/>
+        <input type="submit" name="unfinished" value="Delete Unfinished"/>
     </form:form>
     <br>
     <table class="res">
@@ -54,4 +55,4 @@
         </tbody>
     </table>
 </div>
-<%@ include file="00-footer.jsp" %>
+<%@ include file="00-footer.jsp" %>