예제 #1
0
  /**
   * Update the married status of a new user record.
   *
   * <p>This method demonstrates updating both a UserProfileModel and a UserActionsModel with a
   * single HBase request using the composite dao. It performs a get/update/put operation, which is
   * protected by the check_conflict field on UserProfileModel from colliding with another
   * get/update/put operation.
   *
   * @param firstName The first name of the user we are updating
   * @param lastName The last name of the user we are updating
   * @param married True if this person is married. Otherwise false.
   */
  public void updateUserProfile(String firstName, String lastName, boolean married) {
    // Get the timestamp we'll use to set the value of the profile_updated
    // action.
    long ts = System.currentTimeMillis();

    // Construct the key we'll use to fetch the user.
    PartitionKey key =
        userProfileActionsDao.getPartitionStrategy().partitionKey(lastName, firstName);

    // Get the profile and actions entity from the composite dao.
    UserProfileActionsModel profileActionsModel = userProfileActionsDao.get(key);

    // Updating the married status is hairy since our avro compiler isn't setup
    // to compile setters for fields. We have to construct a clone through the
    // builder.
    UserProfileActionsModel updatedProfileActionsModel =
        UserProfileActionsModel.newBuilder(profileActionsModel)
            .setUserProfileModel(
                UserProfileModel.newBuilder(profileActionsModel.getUserProfileModel())
                    .setMarried(married)
                    .build())
            .build();
    // Since maps are mutable, we can update the actions map without having to
    // go through the builder like above.
    updatedProfileActionsModel
        .getUserActionsModel()
        .getActions()
        .put("profile_updated", Long.toString(ts));

    if (!userProfileActionsDao.put(updatedProfileActionsModel)) {
      // If put returns false, a write conflict occurred where someone else
      // updated the row between the times we did the get and put.
      System.out.println("Updating the user profile failed due to a write conflict");
    }
  }
예제 #2
0
  /**
   * Print the user profiles and actions for all users with the provided last name
   *
   * <p>This method demonstrates how to open a scanner with a start key. It's using the composite
   * dao, so the records it returns will be a composite of both the profile model and actions model.
   *
   * @param lastName The last name of users to scan.
   */
  public void printUserProfileActionsForLastName(String lastName) {
    // Create a partial key that will allow us to start the scanner from the
    // first user record that has last name equal to the one provided.
    PartitionKey startKey = userProfileActionsDao.getPartitionStrategy().partitionKey("lastName");

    // Get the scanner with the start key. Null for stopKey in the getScanner
    // method indicates that the scanner will scan to the end of the table. Our
    // loop will break out when it encounters a record without the last name.

    EntityScanner<UserProfileActionsModel> scanner =
        userProfileActionsDao.getScanner(startKey, null);
    scanner.open();
    try {
      // scan until we find a last name not equal to the one provided
      for (UserProfileActionsModel entity : scanner) {
        if (!entity.getUserProfileModel().getLastName().equals(lastName)) {
          // last name of row different, break out of the scan.
          break;
        }
        System.out.println(entity.toString());
      }
    } finally {
      // scanners need to be closed.
      scanner.close();
    }
  }