Added Task class

src/main/java/ru/windcorp/progressia/common/modules/Task.java

@@ -0,0 +1,66 @@
+package ru.windcorp.progressia.common.modules;
+
+import java.util.ArrayList;
+
+import ru.windcorp.jputil.chars.StringUtil;
+import ru.windcorp.progressia.common.util.crash.CrashReports;
+import ru.windcorp.progressia.common.util.namespaces.Namespaced;
+
+public abstract class Task 
+	extends Namespaced
+	implements Runnable
+	{
+	
+	private boolean done = false;
+	
+	ArrayList<Task> requiredTasks = new ArrayList<Task>();
+
+	public Task(String id) {
+		super(id);
+	}
+
+	@Override
+	public void run() {
+		if (!canRun()) {
+			
+			ArrayList<Task> UndoneTasks = new ArrayList<Task>();
+			for (Task j : requiredTasks) {
+				if (!j.isDone()) {
+					UndoneTasks.add(j);
+				}
+			}
+			
+			
+			throw CrashReports.report(null,
+					"The following required Tasks are not done:\n%s",
+					StringUtil.iterableToString(UndoneTasks, "\n"));
+		}
+		
+		perform();
+		
+		done = true;
+	}
+	
+	// This method will be invoked by Run()
+	protected abstract void perform();
+	
+	public void addRequiredTask(Task task) {
+		if (task.getId() == this.getId()) {
+			throw CrashReports.report(null, 
+					"It is impossible for the Task (%s) to require itself.", 
+					this.getId());
+		}
+		requiredTasks.add(task);
+	}
+	
+	public boolean isDone() {
+		return done;
+	}
+	
+	public boolean canRun() {
+		for (Task j : requiredTasks) {
+			if (!j.isDone()) return false;
+		}
+		return true;
+	}
+}