Read Hashmap In Java

Since hashmap implements serializable interface, you can simply use objectoutputstream class to write whole map to file, and read it again using objectinputstream class below simple code that explain usage of objectoutstream and objectinputstream (with a little help from the comments) your code should be reading into the hashmap already, so i assume your problem is printing the hashmap after reading it in. Articlemapone.put ( ar01, intro to map );

Since hashmap implements serializable interface, you can simply use objectoutputstream class to write whole map to file, and read it again using objectinputstream class below simple code that explain usage of objectoutstream and objectinputstream Hashmap is a part of java.util package. The java.util.hashmap.values() method of hashmap class in java is used to create a collection out of the values of the map.

Hashmap < integer, string > cities_map = new hashmap <integer, string> ();

This method doesn’t take any parameter and returns a collection of values from hashmap. In order to use this class and. System.out.println (map) only gives you the representation of the map object. Now, add some elements to the hashmap −