import org.apache.hadoop.yarn.server.webapp.dao.AppInfo; //导入依赖的package包/类
public AppInfo getApp(HttpServletRequest req, HttpServletResponse res,
    String appId) {
  UserGroupInformation callerUGI = getUser(req);
  final ApplicationId id = parseApplicationId(appId);
  ApplicationReport app = null;
  try {
    if (callerUGI == null) {
      app = appContext.getApplication(id);
    } else {
      app = callerUGI.doAs(
          new PrivilegedExceptionAction<ApplicationReport> () {
        @Override
        public ApplicationReport run() throws Exception {
          return appContext.getApplication(id);
        }
      });
    }
  } catch (Exception e) {
    rewrapAndThrowException(e);
  }
  if (app == null) {
    throw new NotFoundException("app with id: " + appId + " not found");
  }
  return new AppInfo(app);
}
 

import org.apache.hadoop.yarn.server.webapp.dao.AppInfo; //导入依赖的package包/类
@GET
@Path("/apps/{appid}")
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
@Override
public AppInfo getApp(@Context HttpServletRequest req,
    @Context HttpServletResponse res, @PathParam("appid") String appId) {
  init(res);
  return super.getApp(req, res, appId);
}
 

import org.apache.hadoop.yarn.server.webapp.dao.AppInfo; //导入依赖的package包/类
public AppInfo getApp(HttpServletRequest req, HttpServletResponse res,
    String appId) {
  ApplicationId id = parseApplicationId(appId);
  ApplicationReport app = null;
  try {
    app = appContext.getApplication(id);
  } catch (IOException e) {
    throw new WebApplicationException(e);
  }
  if (app == null) {
    throw new NotFoundException("app with id: " + appId + " not found");
  }
  return new AppInfo(app);
}