WaysToInitalizeMap.java

// You can use an initializer in an anonymous subclass to make the syntax a little bit shorter:

Map<String, String> myMap = new HashMap<String, String>() {{
        put("a", "b");
        put("c", "d");
    }};

// In plain java 8 you also have the possibility of using Streams/Collectors to do the job.
Map<String, String> myMap = Stream.of(
         new SimpleEntry<>("key1", "value1"),
         new SimpleEntry<>("key2", "value2"),
         new SimpleEntry<>("key3", "value3"))
        .collect(toMap(SimpleEntry::getKey, SimpleEntry::getValue));

// Using a Stream of a two-dimensional object and collect them into a map:
 Map<String, Integer> map = Stream.of(new Object[][] { 
     { "data1", 1 }, 
     { "data2", 2 }, 
 }).collect(Collectors.toMap(data -> (String) data[0], data -> (Integer) data[1]));