gateway-shell/src/main/java/org/apache/knox/gateway/shell/table/CSVKnoxShellTableBuilder.java

/*
 * 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 org.apache.knox.gateway.shell.table;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.net.URLConnection;
import java.nio.charset.StandardCharsets;

public class CSVKnoxShellTableBuilder extends KnoxShellTableBuilder {

  private boolean withHeaders;

  CSVKnoxShellTableBuilder(long id) {
    super(id);
  }

  public CSVKnoxShellTableBuilder withHeaders() {
    withHeaders = true;
    return this;
  }

  public KnoxShellTable url(String url) throws IOException {
    int rowIndex = 0;
    KnoxShellTable table = null;
    URL urlToCsv = new URL(url);
    URLConnection connection = urlToCsv.openConnection();
    try (Reader urlConnectionStreamReader = new InputStreamReader(connection.getInputStream(), StandardCharsets.UTF_8);
        BufferedReader csvReader = new BufferedReader(urlConnectionStreamReader);) {
      table = new KnoxShellTable();
      if (title != null) {
        table.title(title);
      }
      table.id(id);
      String row = null;
      while ((row = csvReader.readLine()) != null) {
        boolean addingHeaders = (withHeaders && rowIndex == 0);
        if (!addingHeaders) {
          table.row();
        }
        String[] data = row.split(",");

        for (String value : data) {
          if (addingHeaders) {
            table.header(value);
          } else {
            table.value(value);
          }
        }
        rowIndex++;
      }
    }
    return table;
  }

}