Crea una blockchain

LVL2_T353i/Crea_una_Blockchain/Crea_una_Blockchain_Zeeeeeeek/src/Block.java

@@ -0,0 +1,57 @@
+import java.sql.Timestamp;
+import java.util.ArrayList;
+
+
+public class Block {
+    private Timestamp timestamp;
+    private Object data;
+    private int previousHash;
+    private int hash;
+    ArrayList<Block> chain = new ArrayList<Block>();
+    private static boolean isFirst = true;
+
+    public Block(Timestamp timestamp, Object data) {
+        if (!isFirst) throw new IllegalArgumentException("Non è il primo block");
+        this.timestamp = timestamp;
+        this.data = data;
+        this.previousHash = 0;
+        hash = hashCode();
+        chain.add(this);
+        isFirst = false;
+    }
+
+    public Block(Timestamp timestamp, Object data, int previousHash) {
+        this.timestamp = timestamp;
+        this.data = data;
+        this.previousHash = previousHash;
+        hash = hashCode();
+        int temp = chain.size() - 1;
+        chain.add(this);
+    }
+
+    public int getHash() {
+        return hash;
+    }
+    private Block getLastBlock() {
+        return chain.get(chain.size() - 1);
+    }
+    @Override
+    public int hashCode() {
+        int temp = 17;
+        temp = 31 * temp + timestamp.hashCode();
+        temp = 31 * temp + data.hashCode();
+        return temp;
+    }
+
+    public boolean isValidBlock(Block previousBlock) {
+        return (previousHash == previousBlock.hash);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof Block)) return false;
+        Block block = (Block) o;
+        return timestamp.equals(block.timestamp) && data.equals(block.data);
+    }
+}