I have a Array List with HashMap
deviceDataCollection = new ArrayList<HashMap<String,String>>(); I have to retrieve some data from this Array e compare using an IF-STATMENT, like the code below:
String DeviceType = deviceDataCollection.get(position).get("var").toString(); //it returns a string: lamp if (DeviceType == "lamp") { // do something } The problem is: I can't get enter the IF-STATEMENT. I'm sure the values are exact the same.
I don't know what to do.
Thanks.
Use equals("lamp") or equalsIgnoreCase("lamp") method to co0mpare two Strings.
if (DeviceType .equals("lamp")) { // do something } 
When comparing Strings use equals()
So in your conditional it should be DeviceType.equals("lamp")
When you compare reference types in Java (and Android) you need to use the .equals() method:
if (DeviceType.equals("lamp")) { // do something } == determines equality by when something is in memory, .equals() will consider its value.
Try this:
if (DeviceType.equals("lamp")) { // do something } Strings are compared using equals function and not ==.
Use
if ("lamp".equals(DeviceType)) { //do something } The operator, ==, tests to see if two object reference variables refer to the exact same instance of an object.
The method, .equals(), tests to see if the two objects being compared to each other are equivalent -- but they need not be the exact same instance of the same object.
http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html
Check the equals method in the link above
if ("lamp".equals(DeviceType))is what you need!