001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.dataformat.csv;
018    
019    import java.io.InputStream;
020    import java.io.InputStreamReader;
021    import java.io.OutputStream;
022    import java.io.OutputStreamWriter;
023    import java.io.Writer;
024    import java.util.ArrayList;
025    import java.util.Arrays;
026    import java.util.List;
027    import java.util.Map;
028    import java.util.Set;
029    
030    import org.apache.camel.Exchange;
031    import org.apache.camel.spi.DataFormat;
032    import org.apache.camel.util.ExchangeHelper;
033    import org.apache.commons.csv.CSVParser;
034    import org.apache.commons.csv.CSVStrategy;
035    import org.apache.commons.csv.writer.CSVConfig;
036    import org.apache.commons.csv.writer.CSVField;
037    import org.apache.commons.csv.writer.CSVWriter;
038    
039    /**
040     * CSV Data format.
041     * <p/>
042     * By default, columns are autogenerated in the resulting CSV. Subsequent
043     * messages use the previously created columns with new fields being added at
044     * the end of the line. Thus, field order is the same from message to message.
045     * Autogeneration can be disabled. In this case, only the fields defined in
046     * csvConfig are written on the output.
047     *
048     * @version $Revision: 20034 $
049     */
050    public class CsvDataFormat implements DataFormat {
051        private CSVStrategy strategy = CSVStrategy.DEFAULT_STRATEGY;
052        private CSVConfig config = new CSVConfig();
053        private boolean autogenColumns = true;
054        private String delimiter;
055    
056        public void marshal(Exchange exchange, Object object, OutputStream outputStream) throws Exception {
057            if (delimiter != null) {
058                config.setDelimiter(delimiter.charAt(0));
059            }
060    
061            OutputStreamWriter out = new OutputStreamWriter(outputStream);
062            CSVWriter csv = new CSVWriter(config);
063            csv.setWriter(out);
064    
065            try {
066                List list = ExchangeHelper.convertToType(exchange, List.class, object);
067                if (list != null) {
068                    for (Object child : list) {
069                        Map row = ExchangeHelper.convertToMandatoryType(exchange, Map.class, child);
070                        doMarshalRecord(exchange, row, out, csv);
071                    }
072                } else {
073                    Map row = ExchangeHelper.convertToMandatoryType(exchange, Map.class, object);
074                    doMarshalRecord(exchange, row, out, csv);
075                }
076            } finally {
077                out.close();
078            }
079        }
080    
081        private void doMarshalRecord(Exchange exchange, Map row, Writer out, CSVWriter csv) throws Exception {
082            if (autogenColumns) {
083                // no specific config has been set so lets add fields
084                Set set = row.keySet();
085                updateFieldsInConfig(set, exchange);
086            }
087            csv.writeRecord(row);
088        }
089    
090        public Object unmarshal(Exchange exchange, InputStream inputStream) throws Exception {
091            InputStreamReader in = new InputStreamReader(inputStream);
092            if (delimiter != null) {
093                strategy.setDelimiter(delimiter.charAt(0));
094            }
095            
096            try {
097                CSVParser parser = new CSVParser(in, strategy);
098                List<List<String>> list = new ArrayList<List<String>>();
099                while (true) {
100                    String[] strings = parser.getLine();
101                    if (strings == null) {
102                        break;
103                    }
104                    List<String> line = Arrays.asList(strings);
105                    list.add(line);
106                }
107                if (list.size() == 1) {
108                    return list.get(0);
109                } else {
110                    return list;
111                }
112            } finally {
113                in.close();
114            }
115        }
116        
117        public String getDelimiter() {
118            return delimiter;
119        }
120    
121        public void setDelimiter(String delimiter) {
122            if (delimiter != null && delimiter.length() > 1) {
123                throw new IllegalArgumentException("Delimiter must have a length of one!");
124            }
125            this.delimiter = delimiter;
126        }
127        
128        public CSVConfig getConfig() {
129            return config;
130        }
131    
132        public void setConfig(CSVConfig config) {
133            this.config = config;
134        }
135    
136        public CSVStrategy getStrategy() {
137            return strategy;
138        }
139    
140        public void setStrategy(CSVStrategy strategy) {
141            this.strategy = strategy;
142        }
143    
144        public boolean isAutogenColumns() {
145            return autogenColumns;
146        }
147    
148        /**
149         * Auto generate columns.
150         *
151         * @param autogenColumns set to false to disallow column autogeneration (default true)
152         */
153        public void setAutogenColumns(boolean autogenColumns) {
154            this.autogenColumns = autogenColumns;
155        }
156    
157        private synchronized void updateFieldsInConfig(Set set, Exchange exchange) {
158            for (Object value : set) {
159                if (value != null) {
160                    String text = exchange.getContext().getTypeConverter().convertTo(String.class, value);
161                    // do not add field twice
162                    if (config.getField(text) == null) {
163                        CSVField field = new CSVField(text);
164                        config.addField(field);
165                    }
166                }
167            }
168        }
169    
170    }