Chapter 74. CSV DataFormat

The CSV dataformat supports 28 options which are listed below.

The component allows you to marshal a Java Map (or any other message type that can be converted in a Map) into a CSV payload.

Considering the following body

Map<String, Object> body = new LinkedHashMap<>();
body.put("foo", "abc");
body.put("bar", 123);

and this Java route definition

from("direct:start")
    .marshal().csv()
    .to("mock:result");

or this XML route definition

<route>
    <from uri="direct:start" />
    <marshal>
        <csv />
    </marshal>
    <to uri="mock:result" />
</route>

then it will produce

abc,123

Unmarshalling will transform a CSV messsage into a Java List with CSV file lines (containing another List with all the field values).

An example: we have a CSV file with names of persons, their IQ and their current activity.

Jack Dalton, 115, mad at Averell
Joe Dalton, 105, calming Joe
William Dalton, 105, keeping Joe from killing Averell
Averell Dalton, 80, playing with Rantanplan
Lucky Luke, 120, capturing the Daltons

We can now use the CSV component to unmarshal this file:

from("file:src/test/resources/?fileName=daltons.csv&noop=true")
    .unmarshal().csv()
    .to("mock:daltons");

The resulting message will contain a List<List<String>> like…​

List<List<String>> data = (List<List<String>>) exchange.getIn().getBody();
for (List<String> line : data) {
    LOG.debug(String.format("%s has an IQ of %s and is currently %s", line.get(0), line.get(1), line.get(2)));
}

Available as of Camel 2.1

If you have multiple rows of data you want to be marshalled into CSV format you can now store the message payload as a List<Map<String, Object>> object where the list contains a Map for each row.

Given a bean which can handle the incoming data…​

MyCsvHandler.java

// Some comments here
public void doHandleCsvData(List<List<String>> csvData)
{
    // do magic here
}

<route>
        <!-- poll every 10 seconds -->
        <from uri="file:///some/path/to/pickup/csvfiles?delete=true&amp;consumer.delay=10000" />
        <unmarshal><csv /></unmarshal>
        <to uri="bean:myCsvHandler?method=doHandleCsvData" />
</route>

Considering the following body

Map<String, Object> body = new LinkedHashMap<>();
body.put("foo", "abc");
body.put("bar", 123);

and this Java route definition

// Camel version < 2.15
CsvDataFormat oldCSV = new CsvDataFormat();
oldCSV.setDelimiter("|");
from("direct:start")
    .marshal(oldCSV)
    .to("mock:result")

// Camel version >= 2.15
from("direct:start")
    .marshal(new CsvDataFormat().setDelimiter(&#39;|&#39;))
    .to("mock:result")

or this XML route definition

<route>
  <from uri="direct:start" />
  <marshal>
    <csv delimiter="|" />
  </marshal>
  <to uri="mock:result" />
</route>

then it will produce

abc|123

Using autogenColumns, configRef and strategyRef attributes inside XML # DSL

Available as of Camel 2.9.2 / 2.10 and deleted for Camel 2.15

You can customize the CSV Data Format to make use of your own CSVConfig and/or CSVStrategy. Also note that the default value of the autogenColumns option is true. The following example should illustrate this customization.

<route>
  <from uri="direct:start" />
  <marshal>
    <!-- make use of a strategy other than the default one which is 'org.apache.commons.csv.CSVStrategy.DEFAULT_STRATEGY' -->
    <csv autogenColumns="false" delimiter="|" configRef="csvConfig" strategyRef="excelStrategy" />
  </marshal>
  <convertBodyTo type="java.lang.String" />
  <to uri="mock:result" />
</route>

<bean id="csvConfig" class="org.apache.commons.csv.writer.CSVConfig">
  <property name="fields">
    <list>
      <bean class="org.apache.commons.csv.writer.CSVField">
        <property name="name" value="orderId" />
      </bean>
      <bean class="org.apache.commons.csv.writer.CSVField">
        <property name="name" value="amount" />
      </bean>
    </list>
  </property>
</bean>

<bean id="excelStrategy" class="org.springframework.beans.factory.config.FieldRetrievingFactoryBean">
  <property name="staticField" value="org.apache.commons.csv.CSVStrategy.EXCEL_STRATEGY" />
</bean>

Available as of Camel 2.10 and deleted for Camel 2.15

You can instruct the CSV Data Format to skip the first line which contains the CSV headers. Using the Spring/XML DSL:

<route>
  <from uri="direct:start" />
  <unmarshal>
    <csv skipFirstLine="true" />
  </unmarshal>
  <to uri="bean:myCsvHandler?method=doHandleCsv" />
</route>

Or the Java DSL:

CsvDataFormat csv = new CsvDataFormat();
csv.setSkipFirstLine(true);

from("direct:start")
  .unmarshal(csv)
.to("bean:myCsvHandler?method=doHandleCsv");

Using the Spring/XML DSL:

<route>
  <from uri="direct:start" />
  <unmarshal>
    <csv delimiter="|" />
  </unmarshal>
  <to uri="bean:myCsvHandler?method=doHandleCsv" />
</route>

Or the Java DSL:

CsvDataFormat csv = new CsvDataFormat();
CSVStrategy strategy = CSVStrategy.DEFAULT_STRATEGY;
strategy.setDelimiter('|');
csv.setStrategy(strategy);

from("direct:start")
  .unmarshal(csv)
  .to("bean:myCsvHandler?method=doHandleCsv");

CsvDataFormat csv = new CsvDataFormat();
csv.setDelimiter("|");

from("direct:start")
  .unmarshal(csv)
  .to("bean:myCsvHandler?method=doHandleCsv");

CsvDataFormat csv = new CsvDataFormat();
CSVConfig csvConfig = new CSVConfig();
csvConfig.setDelimiter(";");
csv.setConfig(csvConfig);

from("direct:start")
  .unmarshal(csv)
  .to("bean:myCsvHandler?method=doHandleCsv");

Issue in CSVConfig

It looks like that

CSVConfig csvConfig = new CSVConfig();
csvConfig.setDelimiter(';');

doesn’t work. You have to set the delimiter as a String!

To use CSV in your Camel routes you need to add a dependency on camel-csv, which implements this data format.

If you use Maven you can just add the following to your pom.xml, substituting the version number for the latest and greatest release (see the download page for the latest versions).

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-csv</artifactId>
  <version>x.x.x</version>
</dependency>