src/main/java/com/wavesplatform/wavesj/Node.java
public Block getBlock(String signature) throws IOException {
        return wavesJsonMapper.convertValue(send("/blocks/signature/" + signature), Block.class);
    }
public Block getBlock(String signature) throws IOException {
        return wavesJsonMapper.convertValue(send("/blocks/signature/" + signature), Block.class);
    }
Returns block by its signature.

@param signature block signature
@return block object
@throws IOException if no block with the given signature exists