Re: Support Map<String, String> & Map<String, MyString>

From:

albert kao <albertkao3@gmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Thu, 6 Oct 2011 18:09:19 -0700 (PDT)

Message-ID:

<8025a806-035d-4c7e-be5d-c50d12b77ea6@20g2000yqq.googlegroups.com>

On Oct 6, 6:42 pm, Daniel Pitts <newsgroup.nos...@virtualinfinity.net>
wrote:

On 10/6/11 2:07 PM, albert kao wrote:

On Oct 6, 4:23 pm, Daniel Pitts<newsgroup.nos...@virtualinfinity.net>
wrote:

On 10/6/11 1:02 PM, Lew wrote:> albert kao wrote:

The following programs work but I like to combine MyComboBox&
MyComboBox2 into one class so that both Map<String, String> &
Map<String, MyString> data types are supported in the single =

combined

class.
How to do that?

Have 'MyString' implement 'CharSequence' and use a 'Map<String,CharSe=

quence>'?

Or, if you don't really care about the value type, use Map<String, ?> =

the parameter type.

public class MyComboBox {
public MyComboBox(Map<String, ?> data) {...};

}

If you *do* care about the type, then make your ComboBox generic:

public class MyComboBox<V> {
public MyComboBox(Map<String, V> data) {...};

}

public class MyComboBox extends LangComboBox implements
PropertyChangeListener {
protected EventListenerList listenerList = new EventListen=

erList();

private Set keySet = Collections.EMPTY_SET;

DO NOT USE RAW TYPES!

Seconded.

Inside the MyComboBox constructor, is there a way to figure out
whether the type of value of the Map is String or MyString?

Not really, due to type erasure. It might be helpful if you explain
*why* you need the two constructors. What do they do differently?

//Two slightly different types of data stored in java.util.Map.
Map<String, String> map1 = getdata("data1");
Map<String, MyString> map2 = getdata2("data2");

// Use two slightly different ComboBoxes to sort & display the two
types of data
MyComboBox box1 = new MyComboBox(map1);
MyComboBox2 box2 = new MyComboBox2(map2);

// Is there a way to use the same type of ComboBox to sort & display
the two types of data?
MyComboBoxNew box1 = new MyComboBoxNew(map1);
MyComboBoxNew box2 = new MyComboBoxNew(map2);