Java tutorial
/* * Copyright 2012 Janrain, Inc. * * Licensed 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 com.janrain.backplane.server; import com.janrain.backplane.DateTimeUtils; import com.janrain.commons.supersimpledb.SimpleDBException; import com.janrain.commons.supersimpledb.message.MessageField; import com.janrain.commons.util.Pair; import com.janrain.crypto.ChannelUtil; import org.apache.commons.lang.StringUtils; import org.apache.log4j.Logger; import org.codehaus.jackson.map.ObjectMapper; import java.io.IOException; import java.net.MalformedURLException; import java.net.URL; import java.text.ParseException; import java.util.*; /** * @author Johnny Bufu */ public class BackplaneMessage extends ExternalizableCore { // - PUBLIC public BackplaneMessage() { } public BackplaneMessage(String bus, String channel, int defaultExpireSeconds, int maxExpireSeconds, Map<String, Object> data) throws BackplaneServerException, SimpleDBException { Map<String, String> d = new LinkedHashMap<String, String>(toStringMap(data)); String id = generateMessageId(new Date()); d.put(Field.ID.getFieldName(), id); d.put(Field.BUS.getFieldName(), bus); d.put(Field.CHANNEL_NAME.getFieldName(), channel); d.put(Field.PAYLOAD.getFieldName(), extractFieldValueAsJsonString(Field.PAYLOAD, data)); Object sticky = data.get(Field.STICKY.getFieldName()); d.put(Field.STICKY.getFieldName(), sticky != null ? sticky.toString() : Boolean.FALSE.toString()); d.put(Field.EXPIRE.getFieldName(), DateTimeUtils.processExpireTime(sticky, data.get(Field.EXPIRE.getFieldName()), defaultExpireSeconds, maxExpireSeconds)); super.init(id, d); } @Override public String getIdValue() { return get(Field.ID); } @Override public Set<? extends MessageField> getFields() { return EnumSet.allOf(Field.class); } public Pair<String, Date> updateId(Pair<String, Date> lastIdAndDate) { long thisTime = getDateFromId(getIdValue()).getTime(); long lastTime = 0; if (StringUtils.isNotEmpty(lastIdAndDate.getLeft())) { lastTime = getDateFromId(lastIdAndDate.getLeft()).getTime(); } if (thisTime <= lastTime) { logger.warn("message has an id " + getIdValue() + " that is not > the latest id of " + lastIdAndDate.getLeft()); Date newDate = new Date(lastIdAndDate.getRight().getTime() + 1); put(Field.ID.getFieldName(), generateMessageId(newDate)); logger.warn("fixed"); return new Pair<String, Date>(getIdValue(), newDate); } else { return lastIdAndDate; } } public String getBus() { return this.get(Field.BUS); } public String getChannel() { return this.get(Field.CHANNEL_NAME); } public boolean isSticky() { return "true".equalsIgnoreCase(get(Field.STICKY)); } public HashMap<String, Object> asFrame(String version) throws BackplaneServerException { HashMap<String, Object> frame = new LinkedHashMap<String, Object>(); frame.put(Field.ID.getFieldName(), get(BackplaneMessage.Field.ID.getFieldName())); frame.put(Field.CHANNEL_NAME.getFieldName(), get(BackplaneMessage.Field.CHANNEL_NAME.getFieldName())); // don't copy to frame ID, BUS, CHANNEL_NAME verbatim from Message data structure // (and any other, non-Message fields, like ssdb_update_version) Map<String, Object> msg = new LinkedHashMap<String, Object>(); // only add SOURCE, TYPE, STICKY, PAYLOAD to 'message: {...}' msg.put(Field.SOURCE.getFieldName(), get(Field.SOURCE)); msg.put(Field.TYPE.getFieldName(), get(Field.TYPE)); String sticky = get(Field.STICKY.getFieldName()); if (sticky != null) { // print sticky as a (json) boolean msg.put(Field.STICKY.getFieldName(), Boolean.valueOf(sticky)); } if ("v1.3".equalsIgnoreCase(version)) { msg.put(Field.EXPIRE.getFieldName(), get(Field.EXPIRE)); } try { msg.put(BackplaneMessage.Field.PAYLOAD.getFieldName(), (new ObjectMapper()).readValue(get(BackplaneMessage.Field.PAYLOAD), Object.class)); // un-quote the value } catch (IOException e) { String errMsg = "Error deserializing message payload: " + e.getMessage(); logger.error(errMsg); throw new BackplaneServerException(errMsg, e); } frame.put("message", msg); return frame; } public static enum Field implements MessageField { ID("id"), CHANNEL_NAME("channel_name"), BUS("bus"), STICKY("sticky", false) { @Override public void validate(String value) throws SimpleDBException { super.validate(value); if (value != null && !Boolean.TRUE.toString().equalsIgnoreCase(value) && !Boolean.FALSE.toString().equalsIgnoreCase(value)) { throw new IllegalArgumentException( "Invalid boolean value for " + getFieldName() + ": " + value); } } }, EXPIRE("expire", true) { @Override public void validate(String value) throws SimpleDBException { super.validate(value); try { DateTimeUtils.INTERNETDATE.get().parse(value); } catch (ParseException e) { throw new InvalidRequestException( "Invalid Internet Date/Time value for " + getFieldName() + ": " + value); } } }, SOURCE("source") { @Override public void validate(String value) throws SimpleDBException { super.validate(value); try { new URL(value); } catch (MalformedURLException e) { throw new IllegalArgumentException("Invalid URL for " + getFieldName() + ": " + value, e); } } }, TYPE("type"), PAYLOAD("payload"); @Override public String getFieldName() { return fieldName; } @Override public boolean isRequired() { return required; } @Override public void validate(String value) throws SimpleDBException { if (isRequired()) validateNotBlank(getFieldName(), value); } // - PRIVATE private String fieldName; private boolean required = true; private Field(String fieldName) { this(fieldName, true); } private Field(String fieldName, boolean required) { this.fieldName = fieldName; this.required = required; } } public static Date getDateFromId(String backplaneMessageId) { if (StringUtils.isBlank(backplaneMessageId)) { return null; } try { return DateTimeUtils.ISO8601.get() .parse(backplaneMessageId.substring(0, backplaneMessageId.indexOf("Z") + 1)); } catch (ParseException e) { logger.warn(e); } return null; } // - PRIVATE private static final long serialVersionUID = -4601517360705157923L; private static final Logger logger = Logger.getLogger(BackplaneMessage.class); /** * @return a time-based, lexicographically comparable message ID. */ private static String generateMessageId(Date date) { return DateTimeUtils.ISO8601.get().format(date) + "-" + ChannelUtil.randomString(10); } private String extractFieldValueAsJsonString(Field field, Map<String, Object> data) throws BackplaneServerException { try { Object value = data.get(field.getFieldName()); return value == null ? null : (new ObjectMapper()).writeValueAsString(value); } catch (IOException e) { String errMsg = "Error serializing message payload: " + e.getMessage(); logger.error(errMsg); throw new BackplaneServerException(errMsg, e); } } }