import org.apache.hadoop.hdfs.server.namenode.DatanodeDescriptor.BlockTargetPair; //导入依赖的package包/类
/**
 * Create BlockCommand for transferring blocks to another datanode
 * @param blocktargetlist    blocks to be transferred 
 */
public BlockCommand(int action, List<BlockTargetPair> blocktargetlist) {
  super(action);

  blocks = new Block[blocktargetlist.size()]; 
  targets = new DatanodeInfo[blocks.length][];
  for(int i = 0; i < blocks.length; i++) {
    BlockTargetPair p = blocktargetlist.get(i);
    blocks[i] = p.block;
    targets[i] = p.targets;
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.DatanodeDescriptor.BlockTargetPair; //导入依赖的package包/类
public CumulusRecoveryCommand(int action, byte type, byte lostColumn, CodingMatrix matrix, List<BlockTargetPair> blockTargetPairs){
	super(action);
	this.type = type;
	this.lostColumn = lostColumn;
	locatedblks = new LocatedBlock[blockTargetPairs.size()];
	for(int i = 0; i < locatedblks.length; i++) {
      BlockTargetPair p = blockTargetPairs.get(i);
      locatedblks[i]= new LocatedBlock(p.block, p.targets); 
    }
    this.matrix = matrix;
}