I am leaning Java.
I have to transfer a Hashmap to Server using rpc.
HashMap
Map<String, String> testMap = new HashMap<String, String>();
testMap .put("1", "abc");
testMap .put("2", "ezc");
testMap .put("3", "afc");
testMap .put("4", "cvc");
..
how to do that.
Take a look at Jackson JSON processor. In particular the code will look something like:
Map map = your map
ObjectMapper mapper = new ObjectMapper();
String json = mapper.writeValueAsString(map);
If you want pretty JSON (multiple lines) for debugging, then use:
String json = mapper.defaultPrettyPrintingWriter().writeValueAsString(map);
See this link if its helps..
http://www.mkyong.com/java/how-to-convert-java-map-to-from-json-jackson/
import com.fasterxml.jackson.databind.ObjectMapper;
ObjectMapper mapper = new ObjectMapper();
Map<String, String> testMap = new HashMap<String, String>();
testMap .put("1", "abc");
testMap .put("2", "ezc");
testMap .put("3", "afc");
testMap .put("4", "cvc");
mapper.writeValue(new File("c:\\user.json"), testMap);
you can also try GSON library. It is fast and easy to use.
The Below wrapper class will make your job even more easy
public class ConvertJsonToObject {
private static Gson gson = new GsonBuilder().create();
public static final <T> T getFromJSON(String json, Class<T> clazz) {
return gson.fromJson(json, clazz);
}
public static final <T> String toJSON(T clazz) {
return gson.toJson(clazz);
}
}
All you need to do is
Map<String, String> testMap = new HashMap<String, String>();
testMap .put("1", "abc");
testMap .put("2", "ezc");
testMap .put("3", "afc");
testMap .put("4", "cvc");
String json = ConvertJsonToObject.toJSON(testMap);
and you can easily get your original Object back on the other side
Map<String, String> newTestMap = ConvertJsonToObject.getFromJSON(json,Map.class);
I don't catch : HashMap is Serializable so should be able to be used between client and server?
