Java tutorial
package com.utad.flume.interceptor; /** * 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. */ import static com.utad.flume.interceptor.InterceptorTwitterConstantes.OUTPUTTEXT; import static com.utad.flume.interceptor.InterceptorTwitterConstantes.OUTPUTTEXT_DEFAULT; import static com.utad.flume.interceptor.InterceptorTwitterConstantes.OUTPUTUSERNAME; import static com.utad.flume.interceptor.InterceptorTwitterConstantes.OUTPUTUSERNAME_DEFAULT; import static com.utad.flume.interceptor.InterceptorTwitterConstantes.OUTPUTUSERSCREENNAME; import static com.utad.flume.interceptor.InterceptorTwitterConstantes.OUTPUTUSERSCREENNAME_DEFAULT; import java.io.ByteArrayInputStream; import java.io.InputStream; import java.io.InputStreamReader; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import org.apache.flume.Context; import org.apache.flume.Event; import org.apache.flume.event.EventBuilder; import org.apache.flume.interceptor.*; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.gson.stream.JsonReader; /** * Simple Interceptor class that sets the current system timestamp on all events * that are intercepted. * By convention, this timestamp header is named "timestamp" and its format * is a "stringified" long timestamp in milliseconds since the UNIX epoch. */ public class InterceptorTwitterSpark implements Interceptor { private static final Logger logger = LoggerFactory.getLogger(InterceptorTwitterSpark.class); private final boolean textoSalida; private final boolean nombreUsuarioSalida; private final boolean nombrePantallaUsuarioSalida; /** * Only {@link InterceptorTwitterSpark.Builder} can build me */ private InterceptorTwitterSpark(boolean textoSalida, boolean nombreUsuarioSalida, boolean nombrePantallaUsuarioSalida) { this.textoSalida = textoSalida; this.nombreUsuarioSalida = nombreUsuarioSalida; this.nombrePantallaUsuarioSalida = nombrePantallaUsuarioSalida; } @Override public void initialize() { // no-op } /** * Modifies events in-place. */ @Override public Event intercept(Event event) { Map<String, String> headers = new HashMap<String, String>(event.getHeaders()); headers.put("SINKTYPE", "KAFKASPARK"); byte[] body = readJsonStream(new ByteArrayInputStream(event.getBody())); return EventBuilder.withBody(body, headers); } private byte[] readJsonStream(InputStream is) { byte[] body = null; try { JsonReader reader = new JsonReader(new InputStreamReader(is, "UTF-8")); try { long id = 0L; String text = null; String userName = null; String userScreenName = null; reader.beginObject(); while (reader.hasNext()) { String name = reader.nextName(); if (name.equals("id")) { id = reader.nextLong(); } else if (name.equals("text")) { text = reader.nextString(); } else if (name.equals("user")) { reader.beginObject(); while (reader.hasNext()) { name = reader.nextName(); if (name.equals("name")) { userName = reader.nextString(); } else if (name.equals("screen_name")) { userScreenName = reader.nextString(); } else { reader.skipValue(); } } reader.endObject(); } else { reader.skipValue(); } } reader.endObject(); StringBuilder builder = new StringBuilder(); if (textoSalida) { builder = new StringBuilder(text); } logger.debug("id: {}", id); logger.debug("text: {}", text); logger.debug("username: {}", userName); logger.debug("screenName: {}", userScreenName); body = builder.toString().getBytes("UTF-8"); } finally { reader.close(); } } catch (UnsupportedEncodingException e) { logger.error("UTF-8 is not supported on this runtime", e); } catch (IOException e) { logger.error("Caught an IOException", e); } return body; } /** * Delegates to {@link #intercept(Event)} in a loop. * @param events * @return */ @Override public List<Event> intercept(List<Event> events) { List<Event> es = new ArrayList<Event>(); for (Event event : events) { es.add(intercept(event)); event.getHeaders().put("SINKTYPE", "KAFKAJSONSPARK"); es.add(event); } return es; } @Override public void close() { // no-op } /** * Builder which builds new instances of the InterceptorTwitterSpark. */ public static class Builder implements Interceptor.Builder { private boolean outputText = OUTPUTTEXT_DEFAULT; private boolean outputUserName = OUTPUTUSERNAME_DEFAULT; private boolean outputUserScreenName = OUTPUTUSERSCREENNAME_DEFAULT; @Override public Interceptor build() { return new InterceptorTwitterSpark(outputText, outputUserName, outputUserScreenName); } @Override public void configure(Context context) { outputText = context.getBoolean(OUTPUTTEXT, OUTPUTTEXT_DEFAULT); outputUserName = context.getBoolean(OUTPUTUSERNAME, OUTPUTUSERNAME_DEFAULT); outputUserScreenName = context.getBoolean(OUTPUTUSERSCREENNAME, OUTPUTUSERSCREENNAME_DEFAULT); StringBuilder builder = new StringBuilder("outputText: "); builder.append(outputText).append(" outputUserName: ").append(outputUserName) .append(" outputUserScreenName: ").append(outputUserScreenName); logger.debug(builder.toString()); } } }