A modern I/O API for Java
     Okio 1.4.0 API
                 
            
                
                
                MapDB provides concurrent Maps, Sets and Queues backed by disk storage or off-heap-memory. It is a fast and easy to use embedded Java database engine.
     MapDB: Database Engine — MapDB
                 
            
                
                
                Twitter4J is an open-sourced, mavenized and Google App Engine safe Java library for the Twitter API which is released under the Apache License 2.0.
     Twitter4J - A Java library for the Twitter API
                 
            
                
                
                Java HTTP Request Library
     http-request http-request : java http request library
                 
            
                
                
                Backport of Java 8's lambda expressions to Java 7, 6 and 5
                 
            
                
                
                Tiny, easily embeddable HTTP server in Java.
     NanoHttpd-Project –
                 
            
                
                
                A Java API for generating .java source files.
                 
            
                
                
                The Java driver for MongoDB 
     MongoDB Java Driver
                 
            
                
                
                A supplement or replacement for the Java Collections Framework.
                 
            
                
                
                A modern JSON library for Android and Java.