How write Java.util.Map into parcel in a smart way?

I ended up doing it a little differently. It follows the pattern you would expect for dealing with Parcelables, so it should be familiar.

public void writeToParcel(Parcel out, int flags){  out.writeInt(map.size());  for(Map.Entry<String,String> entry : map.entrySet()){    out.writeString(entry.getKey());    out.writeString(entry.getValue());  }}private MyParcelable(Parcel in){  //initialize your map before  int size = in.readInt();  for(int i = 0; i < size; i++){    String key = in.readString();    String value = in.readString();    map.put(key,value);  }}

In my application, the order of the keys in the map mattered. I was using a LinkedHashMap to preserve the ordering and doing it this way guaranteed that the keys would appear in the same order after being extracted from the Parcel.

you can try:

bundle.putSerializable(yourSerializableMap);

if your chosen map implements serializable (like HashMap) and then you can use your writeBundle in ease

If both the key and value of the map extend Parcelable, you can have a pretty nifty Generics solution to this:

Code

// For writing to a Parcelpublic <K extends Parcelable,V extends Parcelable> void writeParcelableMap(        Parcel parcel, int flags, Map<K, V > map){    parcel.writeInt(map.size());    for(Map.Entry<K, V> e : map.entrySet()){        parcel.writeParcelable(e.getKey(), flags);        parcel.writeParcelable(e.getValue(), flags);    }}// For reading from a Parcelpublic <K extends Parcelable,V extends Parcelable> Map<K,V> readParcelableMap(        Parcel parcel, Class<K> kClass, Class<V> vClass){    int size = parcel.readInt();    Map<K, V> map = new HashMap<K, V>(size);    for(int i = 0; i < size; i++){        map.put(kClass.cast(parcel.readParcelable(kClass.getClassLoader())),                vClass.cast(parcel.readParcelable(vClass.getClassLoader())));    }    return map;}

Usage

// MyClass1 and MyClass2 must extend ParcelableMap<MyClass1, MyClass2> map;// Writing to a parcelwriteParcelableMap(parcel, flags, map);// Reading from a parcelmap = readParcelableMap(parcel, MyClass1.class, MyClass2.class);