Create BlockchainManager.java

sidra_chain_integration/project/sidra_nexus/src/BlockchainManager.java

@@ -0,0 +1,23 @@
+package com.sidra.nexus;
+
+import org.web3j.protocol.Web3j;
+import org.web3j.protocol.core.methods.response.TransactionReceipt;
+import org.web3j.protocol.core.methods.response.Web3ClientVersion;
+
+public class BlockchainManager {
+    private Web3j web3j;
+
+    public BlockchainManager() {
+        web3j = Web3j.build(new HttpService("https://mainnet.infura.io/v3/YOUR_PROJECT_ID"));
+    }
+
+    public String getBlockNumber() {
+        Web3ClientVersion web3ClientVersion = web3j.web3ClientVersion().send();
+        return web3ClientVersion.getWeb3ClientVersion();
+    }
+
+    public TransactionReceipt sendTransaction(String from, String to, String value) {
+        // Implement transaction sending logic
+        return null;
+    }
+}