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Check Blockchain's validity for toutsurlebitcoin.fr
public boolean isFirstBlockValid() {
Block firstBlock = blocks.get(0);
if (firstBlock.getIndex() != 0) {
return false;
}
if (firstBlock.getPreviousHash() != null) {
return false;
}
if (firstBlock.getHash() == null ||
!Block.calculateHash(firstBlock).equals(firstBlock.getHash())) {
return false;
}
return true;
}
public boolean isValidNewBlock(Block newBlock, Block previousBlock) {
if (newBlock != null && previousBlock != null) {
if (previousBlock.getIndex() + 1 != newBlock.getIndex()) {
return false;
}
if (newBlock.getPreviousHash() == null ||
!newBlock.getPreviousHash().equals(previousBlock.getHash())) {
return false;
}
if (newBlock.getHash() == null ||
!Block.calculateHash(newBlock).equals(newBlock.getHash())) {
return false;
}
return true;
}
return false;
}
public boolean isBlockChainValid() {
if (!isFirstBlockValid()) {
return false;
}
for (int i = 1; i < blocks.size(); i++) {
Block currentBlock = blocks.get(i);
Block previousBlock = blocks.get(i - 1);
if (!isValidNewBlock(currentBlock, previousBlock)) {
return false;
}
}
return true;
}
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