Github user rmetzger commented on a diff in the pull request:
https://github.com/apache/bahir-flink/pull/17#discussion_r128921971
--- Diff:
flink-connector-kudu/src/main/java/es/accenture/flink/Utils/Utils.java ---
@@ -0,0 +1,447 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package es.accenture.flink.Utils;
+
+import es.accenture.flink.Sink.KuduOutputFormat;
+import es.accenture.flink.Utils.Exceptions.KuduClientException;
+import es.accenture.flink.Utils.Exceptions.KuduTableException;
+import org.apache.kudu.ColumnSchema;
+import org.apache.kudu.ColumnSchema.ColumnSchemaBuilder;
+import org.apache.kudu.Schema;
+import org.apache.kudu.Type;
+import org.apache.kudu.client.*;
+import org.apache.log4j.Logger;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Utils {
+
+ //Kudu variables
+ private KuduClient client;
+ private KuduSession session;
+
+ // LOG4J
+ private final static Logger logger = Logger.getLogger(Utils.class);
+
+ /**
+ * Builder Util Class which creates a Kudu client and log in to be
able to perform operations later
+ * @param host Kudu's host
+ * @throws KuduClientException In case of exception caused by Kudu
Client
+ */
+ public Utils(String host) throws KuduClientException {
+ this.client = new KuduClient.KuduClientBuilder(host).build();
+ if (client == null){
+ throw new KuduClientException("ERROR: param \"host\" not
valid, can't establish connection");
+ }
+ this.session = this.client.newSession();
+ }
+
+ /**
+ * Return an instance of the table indicated in the settings
+ *
+ * In case that the table exists, return an instance of the table
+ * In case that the table doesn't exist, create a new table with the
data provided and return an instance
+ * In both cases,takes into account the way of the table to perfom
some operations or others
+ *
+ * If the mode is CREATE:
+ *
+ * If the table exists: return error (Can not create table
that already exists)
+ * If the table doesn't exist and the list of column names
has not been provided: return error
+ * If the table doesn't exist and the list of column names
has been provided: create a new table with data provided and return an instance
+ *
+ * If the mode is APPEND:
+ *
+ * If the table exists: return the instance in the table
+ * If the table doesn't exist: return error
+ *
+ * If the mode is OVERRIDE:
+ *
+ * If the table exist: delete all rows of this table and return
an instance of it
+ * If the table doesn't exist: return error
+ *
+ *
+ * @param tableName Table name to use
+ * @param tableMode Operations mode for operate with the
table (CREATE, APPEND, OVERRIDE)
+ * @return Instance of the table indicated
+ * @throws KuduTableException In case of can't access to a table o
can't create it (wrong params or not existing table)
+ * @throws KuduException In case of error of Kudu
+ */
+ public KuduTable useTable(String tableName, Integer tableMode) throws
KuduTableException, KuduException {
+ KuduTable table;
+
+ if (tableMode == KuduOutputFormat.CREATE) {
+ logger.error("Bad call method, use useTable(String tableName,
String [] fieldsNames, RowSerializable row) instead");
+ table = null;
+ }else if (tableMode == KuduOutputFormat.APPEND) {
+ logger.info("Modo APPEND");
+ try {
+ if (client.tableExists(tableName)) {
+ //logger.info("SUCCESS: There is the table with the
name \"" + tableName + "\"");
+ table = client.openTable(tableName);
+ } else {
+ logger.error("ERROR: The table doesn't exist");
+ throw new KuduTableException("ERROR: The table doesn't
exist, so can't do APPEND operation");
+ }
+ } catch (Exception e) {
+ throw new KuduTableException("ERROR: param \"host\" not
valid, can't establish connection");
+ }
+ }else if (tableMode == KuduOutputFormat.OVERRIDE) {
+ logger.info("Modo OVERRIDE");
+ try {
+ if (client.tableExists(tableName)) {
+ logger.info("SUCCESS: There is the table with the name
\"" + tableName + "\". Emptying the table");
+ clearTable(tableName);
+ table = client.openTable(tableName);
+ } else {
+ logger.error("ERROR: The table doesn't exist");
+ throw new KuduTableException("ERROR: The table doesn't
exist, so can't do OVERRIDE operation");
+ }
+ } catch (Exception e) {
+ throw new KuduTableException("ERROR: param \"host\" not
valid, can't establish connection");
+ }
+ }else {
+ throw new KuduTableException("ERROR: Incorrect parameters,
please check the constructor method. Incorrect \"tableMode\" parameter.");
+ }
+ return table;
+ }
+
+ /**
+ * Returns an instance of the table requested in parameters
+ * If the table exists, returns an instance of the table
+ * If the table doesn't exist, creates a new table with the data
provided and returns an instance
+ *
+ * @param tableName Table name to use
+ * @param fieldsNames List of names of columns of the table (to
create table)
+ * @param row List of values to insert a row in the table
(to know the types of columns)
+ * @return Instance of the table indicated
+ * @throws IllegalArgumentException In case of wrong parameters
+ * @throws KuduException In case of exception caused by Kudu
+ */
+ public KuduTable useTable(String tableName, String [] fieldsNames,
RowSerializable row) throws IllegalArgumentException, KuduException {
+ KuduTable table;
+
+ if (client.tableExists(tableName)){
+ logger.info("The table exists");
+ table = client.openTable(tableName);
+ } else {
+ if (tableName == null || tableName.equals("")) {
+ throw new IllegalArgumentException("ERROR: Incorrect
parameters, please check the constructor method. Incorrect \"tableName\"
parameter.");
+
+ } else if (fieldsNames == null || fieldsNames[0].isEmpty()) {
+ throw new IllegalArgumentException("ERROR: Incorrect
parameters, please check the constructor method. Missing \"fields\"
parameter.");
+
+ } else if (row == null){
+ throw new IllegalArgumentException("ERROR: Incorrect
parameters, please check the constructor method. Incorrect \"row\" parameter.");
+
+ } else {
+ logger.info("The table doesn't exist");
+ table = createTable(tableName, fieldsNames, row);
+ }
+ }
+ return table;
+ }
+ /**
+ * Create a new Kudu table and return the instance of this table
+ *
+ * @param tableName name of the table to create
+ * @param fieldsNames list name columns of the table
+ * @param row list of values to insert a row in the table(
to know the types of columns)
+ * @return instance of the table indicated
+ * @throws KuduException In case of exception caused by Kudu
+ */
+ public KuduTable createTable (String tableName, String [] fieldsNames,
RowSerializable row) throws KuduException {
+
+ if(client.tableExists(tableName))
+ return client.openTable(tableName);
+
+
+ List<ColumnSchema> columns = new ArrayList<ColumnSchema>();
+ List<String> rangeKeys = new ArrayList<String>(); // Primary key
+ rangeKeys.add(fieldsNames[0]);
+
+ logger.info("Creating the table \"" + tableName + "\"...");
+ for (int i = 0; i < fieldsNames.length; i++){
+ ColumnSchema col;
+ String colName = fieldsNames[i];
+ Type colType = getRowsPositionType(i, row);
+
+ if (colName.equals(fieldsNames[0])) {
+ col = new ColumnSchemaBuilder(colName,
colType).key(true).build();
+ columns.add(0, col);//To create the table, the key must be
the first in the column list otherwise it will give a failure
+ } else {
+ col = new ColumnSchemaBuilder(colName, colType).build();
+ columns.add(col);
+ }
+ }
+ Schema schema = new Schema(columns);
+
+ if(!client.tableExists(tableName))
+ client.createTable(tableName, schema, new
CreateTableOptions().setRangePartitionColumns(rangeKeys).addHashPartitions(rangeKeys,
4));
+ //logger.info("SUCCESS: The table has been created successfully");
+
+
+ return client.openTable(tableName);
+ }
+ /**
+ * Delete the indicated table
+ *
+ * @param tableName name table to delete
+ */
+ public void deleteTable (String tableName){
+
+ logger.info("Deleting the table \"" + tableName + "\"...");
+ try {
+ if(client.tableExists(tableName)) {
+ client.deleteTable(tableName);
+ logger.info("SUCCESS: Table deleted successfully");
+ }
+ } catch (KuduException e) {
+ logger.error("The table \"" + tableName +"\" doesn't exist,
so can't be deleted.", e);
+ }
+ }
+
+ /**
+ * Return the type of the value of the position "pos", like the class
object "Type"
+ *
+ * @param pos Row position
+ * @param row list of values to insert a row in the table
+ * @return element type "pos"-esimo of "row"
+ */
+ public Type getRowsPositionType (int pos, RowSerializable row){
+ Type colType = null;
+ switch(row.productElement(pos).getClass().getName()){
+ case "java.lang.String":
+ colType = Type.STRING;
+ break;
+ case "java.lang.Integer":
+ colType = Type.INT32;
+ break;
+ case "java.lang.Boolean":
+ colType = Type.BOOL;
+ break;
+ default:
+ break;
+ }
+ return colType;
+ }
+
+ /**
+ * Return a list with all rows of the indicated table
+ *
+ * @param tableName Table name to read
+ * @return List of rows in the table(object Row)
+ * @throws KuduException In case of exception caused by Kudu
+ */
+ public List<RowSerializable> readTable (String tableName) throws
KuduException {
+
+ KuduTable table = client.openTable(tableName);
+ KuduScanner scanner = client.newScannerBuilder(table).build();
+ //Obtain the column name list
+ String[] columnsNames = getNamesOfColumns(table);
+ //The list return all rows
+ List<RowSerializable> rowsList = new ArrayList<>();
+
+ int posRow = 0;
+ while (scanner.hasMoreRows()) {
+ for (RowResult row : scanner.nextRows()) { //Get the rows
+ RowSerializable rowToInsert = new
RowSerializable(columnsNames.length);
+ for (String col : columnsNames) { //For each column, it's
type determined and this is how to read it
+
+ String colType = row.getColumnType(col).getName();
+ switch (colType) {
+ case "string":
+ rowToInsert.setField(posRow,
row.getString(col));
+ posRow++;
+ break;
+ case "int32":
+ rowToInsert.setField(posRow, row.getInt(col));
+ posRow++;
+ break;
+ case "bool":
+ rowToInsert.setField(posRow,
row.getBoolean(col));
+ posRow++;
+ break;
+ default:
+ break;
+ }
+ }
+ rowsList.add(rowToInsert);
+ posRow = 0;
+ }
+ }
+ return rowsList;
+ }
+
+
+
+ /**
+ * Return a list with all rows of the indicated table
+ *
+ * @param tableName Table name to read
+ * @throws KuduException In case of exception caused by Kudu
+ */
+ public void readTablePrint (String tableName) throws KuduException {
+ KuduTable table = client.openTable(tableName);
+ KuduScanner scanner = client.newScannerBuilder(table).build();
+ int cont = 0;
+ try {
+ while (scanner.hasMoreRows()) {
+ RowResultIterator results = scanner.nextRows();
+ while (results.hasNext()) {
+ RowResult result = results.next();
+ System.out.println(result.rowToString());
+ cont++;
+ }
+ }
+ System.out.println("Number of rows: " + cont);
+ } catch (Exception e) {
+ e.printStackTrace();
+ } finally {
+ try {
+ client.shutdown();
+ } catch (Exception e) {
+ e.printStackTrace();
+ }
+ }
+ }
+
+ /**
+ * Returns a representation on the table screen of a table
+ *
+ * @param row row to show
+ * @return a string containing the data of the row indicated in
the parameter
+ */
+ public String printRow (RowSerializable row){
+ String res = "";
+ for(int i = 0; i< row.productArity(); i++){
+ res += (row.productElement(i) + " | ");
--- End diff --
I would recommend using a StringBuilder here
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
