import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.NodesInfo; //导入依赖的package包/类
/**
 * Returns all nodes in the cluster. If the states param is given, returns
 * all nodes that are in the comma-separated list of states.
 */
@GET
@Path("/nodes")
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
public NodesInfo getNodes(@QueryParam("states") String states) {
  init();
  ResourceScheduler sched = this.rm.getResourceScheduler();
  if (sched == null) {
    throw new NotFoundException("Null ResourceScheduler instance");
  }
  
  EnumSet<NodeState> acceptedStates;
  if (states == null) {
    acceptedStates = EnumSet.allOf(NodeState.class);
  } else {
    acceptedStates = EnumSet.noneOf(NodeState.class);
    for (String stateStr : states.split(",")) {
      acceptedStates.add(
          NodeState.valueOf(StringUtils.toUpperCase(stateStr)));
    }
  }
  
  Collection<RMNode> rmNodes = RMServerUtils.queryRMNodes(this.rm.getRMContext(),
      acceptedStates);
  NodesInfo nodesInfo = new NodesInfo();
  for (RMNode rmNode : rmNodes) {
    NodeInfo nodeInfo = new NodeInfo(rmNode, sched);
    if (EnumSet.of(NodeState.LOST, NodeState.DECOMMISSIONED, NodeState.REBOOTED)
        .contains(rmNode.getState())) {
      nodeInfo.setNodeHTTPAddress(EMPTY);
    }
    nodesInfo.add(nodeInfo);
  }
  
  return nodesInfo;
}
 

import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.NodesInfo; //导入依赖的package包/类
/**
 * Returns all nodes in the cluster. If the states param is given, returns
 * all nodes that are in the comma-separated list of states.
 */
@GET
@Path("/nodes")
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
public NodesInfo getNodes(@QueryParam("states") String states) {
  init();
  ResourceScheduler sched = this.rm.getResourceScheduler();
  if (sched == null) {
    throw new NotFoundException("Null ResourceScheduler instance");
  }
  
  EnumSet<NodeState> acceptedStates;
  if (states == null) {
    acceptedStates = EnumSet.allOf(NodeState.class);
  } else {
    acceptedStates = EnumSet.noneOf(NodeState.class);
    for (String stateStr : states.split(",")) {
      acceptedStates.add(NodeState.valueOf(stateStr.toUpperCase()));
    }
  }
  
  Collection<RMNode> rmNodes = RMServerUtils.queryRMNodes(this.rm.getRMContext(),
      acceptedStates);
  NodesInfo nodesInfo = new NodesInfo();
  for (RMNode rmNode : rmNodes) {
    NodeInfo nodeInfo = new NodeInfo(rmNode, sched);
    if (EnumSet.of(NodeState.LOST, NodeState.DECOMMISSIONED, NodeState.REBOOTED)
        .contains(rmNode.getState())) {
      nodeInfo.setNodeHTTPAddress(EMPTY);
    }
    nodesInfo.add(nodeInfo);
  }
  
  return nodesInfo;
}