java.lang.ClassCastException cannot be cast to java.util.Map$Entry

Question

I have this problem I can't solve :

I'm getting some data from fire base database. Every thing works fins except when I reach the title column because the title column is a json tree and it have a key values rows so a new logic must be writen here.

What I tried so far
Create an entry for it and save it in hash map inside my ConfigItem class that I created.

I receive the data just fine, but I don't know who to loop through it.

When I reach the third line in the while loop, I gotjava.lang.ClassCastException: java.util.HashMap$EntrySet cannot be cast to java.util.Map$Entry

What I'm missing here?

public class DataMappingConfig implements DataMappingStrategy {

@Override
public Object mapData(HashMap<String, Object> data ) {

    Log.i("key set " , data.keySet().toString() + " key set ") ;
    HashMap<String , Object > mpair  =null ;
    HashMap<String, String> titlepairs = null ;

    for (String key : data.keySet()) {
        if (key.equals(KEY_TITLE)) {

            final Iterator iterator = data.entrySet().iterator();

            while (iterator.hasNext()){
                mpair = new HashMap<String , Object >() ;
                Map.Entry<String, Object> pair = (Map.Entry<String , Object>) data.entrySet() ;
                HashMap<String,HashMap<String , String>> titleMap = (HashMap<String, HashMap<String, String>>) pair.getValue();
                titlepairs = new HashMap<String, String>();;

            }
        }
    }
        ConfigItem conf = new ConfigItem();
        if (data.containsKey(KEY_LOGIN)) {
            conf.setLogin((Boolean) data.get(KEY_LOGIN)); // note the import above
        }
        if (data.containsKey(KEY_ICON)) {
            conf.setIcon((String) data.get(KEY_ICON));
        }
        if (data.containsKey(KEY_MAIN_SCREEN_ORDER)) {
            conf.setNum(safeLongToInt((Long) data.get(KEY_MAIN_SCREEN_ORDER)));
        }
        if (data.containsKey(KEY_MODE)) {
            String modeValue = (String) data.get(KEY_MODE);
            if (modeValue.equals(VALUE_MODE_EMERGENCY)) {
                conf.setEmenrgency(true);
            } else if (modeValue.equals(VALUE_MODE_ROUTINE)) {
                conf.setRoutine(true);
            }
            conf.setMode((String) data.get(KEY_MODE));
        }
        if (data.containsKey(KEY_STATUS)) {
            conf.setStatus((String) data.get(KEY_STATUS));
        }
        if (data.containsKey(KEY_SHOW_DATE)) {
            try {

                conf.setShowDate((Boolean) data.get(KEY_SHOW_DATE));
            } catch (IllegalArgumentException e) {
                e.printStackTrace();
                Log.i("ERROR", "" + e.getLocalizedMessage());
            }
        }


        Log.i("Data Map config ", "conf item = " + conf.toString() + "\n");


        return conf;
    }

}

@Wajdi: If your problem has been solved, add an answer and accept that. If you think the question is not useful anymore delete it. Either way: don't remove the question body. — Frank van Puffelen
– Frank van Puffelen, Commented Jun 14, 2017 at 13:37

Eran · Accepted Answer · 2017-06-14 11:07:08Z

0

You are trying to cast a Set to a Map.Entry.

Since your loop's condition is while (iterator.hasNext()), I'm assuming you intended to use iterator.next() inside the loop.

Change:

Map.Entry<String, Object> pair = (Map.Entry<String , Object>) data.entrySet();

to:

Map.Entry<String, Object> pair = (Map.Entry<String , Object>) iterator.next();

Or even better, change:

final Iterator iterator = data.entrySet().iterator();

to:

final Iterator<Map.Entry<String , Object>> iterator = data.entrySet().iterator();

And then you won't need that cast at all:

while (iterator.hasNext()){
    mpair = new HashMap<String , Object >() ;
    Map.Entry<String, Object> pair = iterator.next();
    HashMap<String,HashMap<String , String>> titleMap = (HashMap<String, HashMap<String, String>>) pair.getValue();
    titlepairs = new HashMap<String, String>();
}

edited Jun 14, 2017 at 11:07

answered Jun 14, 2017 at 11:01

Eran

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Comments

mikep · Accepted Answer · 2017-06-14 11:18:05Z

0

The line

Map.Entry<String, Object> pair = (Map.Entry<String , Object>) data.entrySet() ;

should be

Map.Entry<String, Object> pair = (Map.Entry<String , Object>) iterator.next();

answered Jun 14, 2017 at 11:18

mikep

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1 Comment

mikep Over a year ago

@wajdi, if either is correct then please accept one.

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