Java tutorial
/** * 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.camel.dataformat.bindy.kvp; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.Map; import java.util.Scanner; import org.apache.camel.Exchange; import org.apache.camel.dataformat.bindy.BindyAbstractDataFormat; import org.apache.camel.dataformat.bindy.BindyAbstractFactory; import org.apache.camel.dataformat.bindy.BindyKeyValuePairFactory; import org.apache.camel.dataformat.bindy.util.Converter; import org.apache.camel.spi.DataFormat; import org.apache.camel.spi.PackageScanClassResolver; import org.apache.camel.util.IOHelper; import org.apache.camel.util.ObjectHelper; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * A <a href="http://camel.apache.org/data-format.html">data format</a> ( * {@link DataFormat}) using Bindy to marshal to and from CSV files */ public class BindyKeyValuePairDataFormat extends BindyAbstractDataFormat { private static final transient Log LOG = LogFactory.getLog(BindyKeyValuePairDataFormat.class); public BindyKeyValuePairDataFormat() { } public BindyKeyValuePairDataFormat(String... packages) { super(packages); } @SuppressWarnings("unchecked") public void marshal(Exchange exchange, Object body, OutputStream outputStream) throws Exception { BindyAbstractFactory factory = getFactory(exchange.getContext().getPackageScanClassResolver()); List<Map<String, Object>> models = (ArrayList<Map<String, Object>>) body; byte[] crlf; // Get CRLF crlf = Converter.getByteReturn(factory.getCarriageReturn()); for (Map<String, Object> model : models) { String result = factory.unbind(model); byte[] bytes = exchange.getContext().getTypeConverter().convertTo(byte[].class, exchange, result); outputStream.write(bytes); // Add a carriage return outputStream.write(crlf); } } public Object unmarshal(Exchange exchange, InputStream inputStream) throws Exception { BindyKeyValuePairFactory factory = (BindyKeyValuePairFactory) getFactory( exchange.getContext().getPackageScanClassResolver()); // List of Pojos List<Map<String, Object>> models = new ArrayList<Map<String, Object>>(); // Pojos of the model Map<String, Object> model; InputStreamReader in = new InputStreamReader(inputStream); // Scanner is used to read big file Scanner scanner = new Scanner(in); // Retrieve the pair separator defined to split the record ObjectHelper.notNull(factory.getPairSeparator(), "The pair separator property of the annotation @Message"); String separator = factory.getPairSeparator(); int count = 0; try { while (scanner.hasNextLine()) { // Read the line String line = scanner.nextLine().trim(); if (ObjectHelper.isEmpty(line)) { // skip if line is empty continue; } // Increment counter count++; // Create POJO model = factory.factory(); // Split the message according to the pair separator defined in // annotated class @Message List<String> result = Arrays.asList(line.split(separator)); if (result.size() == 0 || result.isEmpty()) { throw new java.lang.IllegalArgumentException("No records have been defined in the KVP !"); } if (result.size() > 0) { // Bind data from message with model classes // Counter is used to detect line where error occurs factory.bind(result, model, count); // Link objects together factory.link(model); // Add objects graph to the list models.add(model); if (LOG.isDebugEnabled()) { LOG.debug("Graph of objects created : " + model); } } } // Test if models list is empty or not // If this is the case (correspond to an empty stream, ...) if (models.size() == 0) { throw new java.lang.IllegalArgumentException("No records have been defined in the KVP !"); } else { return models; } } finally { scanner.close(); IOHelper.close(in, "in", LOG); } } protected BindyAbstractFactory createModelFactory(PackageScanClassResolver resolver) throws Exception { return new BindyKeyValuePairFactory(resolver, getPackages()); } }