JarCastingsimple_blockchain 
A simple implementation of blockchain using java socket to communicate The blocks can contain any Object implementing Serializable as data.
Communication
All the connections are peer to peer connection using java sockets. Each connection to another node aware of the blockchain will create a new Thread to both JVM connected.
Usage
create new node
To create a new Node, there are two possibilities :
// Create a new chain and is ready for new connections on port 8080
int listeningPort = 8080;
MyDataObject data = new MyDataObject();
Node<MyDataObject> node = new Node<>(listeningPort, new Block<>(data));
OR
//Connect to 192.168.0.1:8080, get the current chain and is ready for new connections on port 8080
int listeningPort = 8080;
String remoteHost = "192.168.0.1";
int remotePort = 8080;
Node<MyDataObject> node = new Node<>(listeningPort, remoteHost, remotePort);
Get the data of a block
Block<MyDataObject> block = node.getBlockChain();
MyDataObject data = block.getData();
Get latest block
Block<MyDataObject> latest = node.getBlockChain();
Add new Block to the chain
MyDataObject data = new MyDataObject();
node.addBlock(data);
Iterate through whole block chain
All of the next cases iterate through the block sorted by creation date
orEach
for(Block<MyDataObject> block : node.getBlockChain()) {
//Do some stuff
}
Iterator
Iterator<Block<MyDataObject>> itr = node.getBlockChain().iterator();
while (itr.hasNext()) {
Block<MyDataObject> block = itr.next();
//Do some stuff
}
Java 8 Stream API
node.getBlockChain().stream().forEach(block -> {
//Do somme stuff
});
Check the validity of a block
Block<MyDataObject> block = node.getBlockChain();
block.isValid();
Check the validity of the chain
Block<MyDataObject> block = node.getBlockChain();
block.isWholeChainValid();
Javadoc
Javadoc can be find here