guava - w3toppers.com

Map implementation with duplicate keys

You are searching for a multimap, and indeed both commons-collections and Guava have several implementations for that. Multimaps allow for multiple keys by maintaining a collection of values per key, i.e. you can put a single object into the map, but you retrieve a collection. If you can use Java 5, I would prefer Guava’s … Read more

Why does compiler gives this exception [closed]

First off, a few things to note. First, compilers do not give Exceptions, they give compilation errors – what you are experiencing is at runtime, not compile-time. Second, fileIn.exists() != false is equivalent to fileIn.exists(), which is easier to read. The actual problem you’re receiving is because your condition is false – which implies in … Read more