Fixed FindBugs warnings

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/NetDatacenterBroker.java

@@ -146,7 +146,7 @@ public class NetDatacenterBroker extends SimEntity {
 		getCloudletList().addAll(list);
 	}
 
-	public void setLinkDC(NetworkDatacenter alinkDC) {
+	public static void setLinkDC(NetworkDatacenter alinkDC) {
 		linkDC = alinkDC;
 	}
 

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/NetworkDatacenter.java

@@ -80,7 +80,7 @@ public class NetworkDatacenter extends Datacenter {
 		Switchlist = new HashMap<Integer, Switch>();
 	}
 
-	public Map<Integer, Integer> VmToSwitchid;
+	public Map<Integer, Integer> VmToSwitchid = new HashMap<Integer, Integer>();
 
 	public Map<Integer, Integer> HostToSwitchid;
 

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/Switch.java

@@ -9,6 +9,7 @@
 package org.cloudbus.cloudsim.network.datacenter;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -64,13 +65,13 @@ public class Switch extends SimEntity {
 	// something is running on these hosts
 	public SortedMap<Double, List<NetworkVm>> fintimelistVM = new TreeMap<Double, List<NetworkVm>>();
 
-	public ArrayList<NetworkPacket> pktlist;
+	public ArrayList<NetworkPacket> pktlist = new ArrayList<NetworkPacket>();
 
 	public List<Vm> BagofTaskVm = new ArrayList<Vm>();
 
 	public double switching_delay;
 
-	public Map<Integer, NetworkVm> Vmlist;
+	public Map<Integer, NetworkVm> Vmlist = new HashMap<Integer, NetworkVm>();
 
 	public Switch(String name, int level, NetworkDatacenter dc) {
 		super(name);

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/util/MathUtil.java

@@ -311,7 +311,7 @@ public class MathUtil {
 
 		double[] estimates = tricubeBySquareRegression.regress()
 				.getParameterEstimates();
-		if (estimates[0] == Double.NaN || estimates[1] == Double.NaN) {
+		if (Double.isNaN(estimates[0]) || Double.isNaN(estimates[1])) {
 			return tricubeRegression.regress().getParameterEstimates();
 		}
 		return estimates;

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/util/WorkloadFileReader.java

@@ -404,8 +404,9 @@ public class WorkloadFileReader implements WorkloadModel {
 
 			// read one line at the time
 			int line = 1;
-			while (reader.ready()) {
-				parseValue(reader.readLine(), line);
+			String readLine = null;
+			while (reader.ready() && (readLine = reader.readLine()) != null) {
+				parseValue(readLine, line);
 				line++;
 			}
 
@@ -435,9 +436,10 @@ public class WorkloadFileReader implements WorkloadModel {
 			reader = new BufferedReader(new InputStreamReader(new GZIPInputStream(new FileInputStream(fl))));
 
 			// read one line at the time
-			int line = 1;
-			while (reader.ready()) {
-				parseValue(reader.readLine(), line);
+			int line = 1;                       
+			String readLine = null;
+                        while (reader.ready() && (readLine = reader.readLine()) != null) {
+				parseValue(readLine, line);
 				line++;
 			}
 
@@ -475,9 +477,10 @@ public class WorkloadFileReader implements WorkloadModel {
 				reader = new BufferedReader(new InputStreamReader(zipFile.getInputStream(zipEntry)));
 
 				// read one line at the time
-				int line = 1;
-				while (reader.ready()) {
-					parseValue(reader.readLine(), line);
+				int line = 1;                       
+				String readLine = null;
+	                        while (reader.ready() && (readLine = reader.readLine()) != null)  {
+					parseValue(readLine, line);
 					line++;
 				}