Freedom9339 commented on code in PR #10013: URL: https://github.com/apache/nifi/pull/10013#discussion_r2225972269
########## nifi-extension-bundles/nifi-parquet-bundle/nifi-parquet-content-viewer/src/main/java/org/apache/parquet/web/controller/ParquetContentViewerController.java: ########## @@ -0,0 +1,167 @@ +/* + * 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.parquet.web.controller; + +import com.google.gson.Gson; +import com.google.gson.GsonBuilder; +import com.google.gson.JsonParser; +import jakarta.servlet.ServletContext; +import jakarta.servlet.http.HttpServlet; +import jakarta.servlet.http.HttpServletRequest; +import jakarta.servlet.http.HttpServletResponse; +import org.apache.avro.generic.GenericRecord; +import org.apache.hadoop.conf.Configuration; +import org.apache.nifi.authorization.AccessDeniedException; +import org.apache.nifi.web.ContentAccess; +import org.apache.nifi.web.ContentRequestContext; +import org.apache.nifi.web.DownloadableContent; +import org.apache.nifi.web.HttpServletContentRequestContext; +import org.apache.nifi.web.ResourceNotFoundException; +import org.apache.parquet.avro.AvroParquetReader; +import org.apache.parquet.hadoop.ParquetReader; +import org.apache.parquet.io.InputFile; +import org.apache.nifi.parquet.shared.NifiParquetInputFile; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import java.io.ByteArrayInputStream; +import java.io.IOException; +import java.io.InputStream; +import java.net.HttpURLConnection; +import java.util.ArrayList; +import java.util.List; + +public class ParquetContentViewerController extends HttpServlet { + private static final Logger logger = LoggerFactory.getLogger(ParquetContentViewerController.class); + + @Override + public void doGet(final HttpServletRequest request, final HttpServletResponse response) throws IOException { + final ContentRequestContext requestContext = new HttpServletContentRequestContext(request); + + final ServletContext servletContext = request.getServletContext(); + final ContentAccess contentAccess = (ContentAccess) servletContext.getAttribute("nifi-content-access"); + // get the content + final DownloadableContent downloadableContent; + try { + downloadableContent = contentAccess.getContent(requestContext); + } catch (final ResourceNotFoundException e) { + logger.warn("Content not found", e); + response.sendError(HttpURLConnection.HTTP_NOT_FOUND, "Content not found"); + return; + } catch (final AccessDeniedException e) { + logger.warn("Content access denied", e); + response.sendError(HttpURLConnection.HTTP_FORBIDDEN, "Content access denied"); + return; + } catch (final Exception e) { + logger.warn("Content retrieval failed", e); + response.sendError(HttpURLConnection.HTTP_INTERNAL_ERROR, "Content retrieval failed"); + return; + } + + response.setStatus(HttpServletResponse.SC_OK); + + final boolean formatted = Boolean.parseBoolean(request.getParameter("formatted")); + if (!formatted) { + final InputStream contentStream = downloadableContent.getContent(); + contentStream.transferTo(response.getOutputStream()); + return; + } + + // allow the user to drive the data type but fall back to the content type if necessary + String displayName = request.getParameter("mimeTypeDisplayName"); + if (displayName == null) { + displayName = downloadableContent.getType(); + } + + if (displayName == null || !(displayName.equals("parquet") || displayName.equals("application/vnd.apache.parquet"))) { + response.sendError(HttpURLConnection.HTTP_BAD_REQUEST, "Unknown content type"); + return; + } + + try { + //Convert InputStream to a seekable InputStream + long maxBytes = 1024 * 1024 * 2; //10MB + byte[] data = getInputStreamBytes(downloadableContent.getContent(), maxBytes); + + if (data.length < 1) { + response.getOutputStream().write("Content size is too large to display.".getBytes()); + return; + } + + Configuration conf = new Configuration(); + conf.setBoolean("parquet.avro.readInt96AsFixed", true); + + final InputFile inputFile = new NifiParquetInputFile(new ByteArrayInputStream(data), data.length); + final ParquetReader<GenericRecord> reader = AvroParquetReader.<GenericRecord>builder(inputFile) + .withConf(conf) + .build(); + + //Get each column per record and save it to corresponding column list + GenericRecord record; + Gson gson = new GsonBuilder().setPrettyPrinting().create(); + boolean firstRecord = true; + + while ((record = reader.read()) != null) { + if (firstRecord) { + firstRecord = false; + } else { + response.getOutputStream().write(",\n".getBytes()); + } + + response.getOutputStream().write(gson.toJson(JsonParser.parseString(record.toString())).getBytes()); Review Comment: I refactored to use Jackson, But I'm not sure how to make it to where record variable is not needed. -- This is an automated message from the Apache Git Service. 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