能否通过区块高度使用bitcoinj获取区块？已查API仅支持哈希方式

Hey there! Great question—yes, you absolutely can retrieve a block using its height with bitcoinj, even though the block hash method might be more prominently documented. Here's how to do it:

Core Approach #

The key is using the BlockChain class paired with your BlockStore instance. First, make sure your node has synced up to at least the target block height (or has the block data stored locally).

Example Code Snippet #

// Assume you've already initialized your BlockChain and BlockStore instances
long targetHeight = 700000;

// Get the StoredBlock for the target height
StoredBlock storedBlock = blockChain.getBlock(targetHeight);

if (storedBlock != null) {
    // Access the block header directly
    BlockHeader blockHeader = storedBlock.getHeader();
    System.out.println("Block header hash: " + blockHeader.getHashAsString());

    // If you need the full Block (only works if you're running a full node with full block storage)
    Block fullBlock = blockStore.get(blockHeader.getHash());
    if (fullBlock != null) {
        // Work with the full block data (transactions, etc.)
        System.out.println("Number of transactions in block: " + fullBlock.getTransactions().size());
    }
} else {
    // The block at this height hasn't been synced yet, or doesn't exist
    System.out.println("Oops, block at height " + targetHeight + " isn't available locally.");
}

Important Notes #

• Light vs Full Nodes: If you're running a light node (only syncing block headers), you'll only be able to access the block header data—full transaction details won't be available. You need a full node that stores complete blocks to get the full Block object.
• Check Sync Status: Always verify that your node's best chain height is at or above your target height first using blockChain.getBestChainHeight(). If the target is higher than this, getBlock() will return null.
• StoredBlock vs Block: The getBlock() method returns a StoredBlock, which includes the block header plus chain work proof. To get the full block with transactions, you'll need to fetch it from the BlockStore using the header's hash, as shown above.

内容的提问来源于stack exchange，提问作者Rung K