如何使用附加字段丰富 csv 内容数据，并使用 apache camel 将管道作为分隔符转换为文本文件

Question

I have a csv file with input content separated with comma ",". I want to convert that into text file with "|"delimiter. I'm using apache camel CsvDataFormat to convert the given csv data format.I can be able to convert the csv content to pipe delimited string. I have two more constants which I have assigned to two variables.I would like to enrich the content of the output data with two additional fields as shown in expected output.

Input

test.csv

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

Test.java

public class Test{
    private String name = "Hell0";
    private String address = "134 johen rd";
}

ConverterRoute.java

public class ConverterRoute implements RoutesBuilder {

    private static final String SOURCE_INPUT_PATH = "file://inbox?fileName=test.csv";

    private static final String SOURCE_OUTPUT_PATH = "file://outbox?fileName=file.txt";

    public void addRoutesToCamelContext(CamelContext context) throws Exception {

        context.addRoutes(new RouteBuilder() {
            public void configure() {
                try {
                    CsvDataFormat csvDataFormat = new CsvDataFormat();
                    csvDataFormat.setDelimiter('|');
                    csvDataFormat.setHeaderDisabled(true);

                    from(SOURCE_INPUT_PATH).
                            unmarshal().csv().
                            marshal(csvDataFormat).
                            to(SOURCE_OUTPUT_PATH)
                            .end();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
}

Output

file.txt

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

Expected Output

file.txt

Jack Dalton| 115 | mad at Averell | Hell0 | 134 johen rd
Joe Dalton| 105 | calming Joe | Hell0 | 134 johen rd
William Dalton | 105 | keeping Joe from killing | Hell0 | 134 johen rd
Averell Averell Dalton| 80| playing with Rantanplan | Hell0 | 134 johen rd
Lucky Luke| 120| capturing the Daltons | Hell0 | 134 johen rd

In the above output file.txt the last two columns are the two constants which I have in my Test.java pojo class. I would like to enrich my pojo fields into the final output. Is there a way I can achieve the result.

Answer 1

In your route after the step

unmarshal().csv()

you got a List<List<String>> as message body. Every list entry of the outer list represents a CSV line and each inner list contains the values of a line.

What you want to do is to add two values to each inner list.

Since your values are the same for every "line", it is probably the most simple approach to write a plain Java Bean that takes the List<List<String>> , iterates over the outer list and adds the two values (list entries) to each inner list.

in your Camel route you call this bean with

.bean(YourBean.class, "methodname")

but methodname is only needed when the Bean has multiple methods.

And then your route continues with

.marshal(csvDataFormat)
.to(SOURCE_OUTPUT_PATH)

This should generate the file you want.

By the way, the .end() at the end of the route is not needed.