How to transform JSON file with key values to apache camel headers - Spring DSL

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I have a JSON File with key value pairs and I want to put the key value pairs into headers. So when I have a file with content like this:

[{"msgId": "8600C5A3-C666-4E63-BFDB-52BCF557F938", "jiraId": "ERR002"}]

I want to create headers with the name msgId and with value "8600C5A3-C666-4E63-BFDB-52BCF557F938", etc.

Or as an alternative: Is there a way to store the headers of an exchange to a file to which later on the headers can be restored in another exchange?

Thank you.

EDIT: My fork of the example.

    public void jsonToHeaders(String body, @Headers Map<String, String> headers) throws ParseException {

        LOG.info("Starting JSON conversion...");
        LOG.debug("Body input, content: {} ", body);
        JSONParser parser = new JSONParser();
        JSONObject jsonObject = (JSONObject) parser.parse(body);
        if (jsonObject != null) 
        { 
            String stringValue = null;
            String stringKey = null ;
            final String NA_STRING = "*** N/A ***";

            for (Object key : jsonObject.keySet()) {

                stringKey = ((key == null) ? NA_STRING : (String)key);
                stringValue = ((jsonObject.get(stringKey) == null) ? NA_STRING : jsonObject.get(stringKey).toString());
                headers.put(stringKey, stringValue);
                LOG.debug("Processing key {} with value {}", stringKey, stringValue);
            }
            LOG.info("Done processed JSON: {}", headers.toString());
        }
    }
spring-camel spring-boot apache-camel json
2 Answers

You can use bean for this case.

JSONToHeadersBean


package org.mybean;


import org.apache.camel.Headers;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

public class JSONToHeadersBean {

    public void jsonToHeaders(String body, @Headers Map<String, String> headers) throws ParseException {
        JSONParser parser = new JSONParser();
        JSONObject object = (JSONObject) parser.parse(body);
        object.keySet().forEach(key -> headers.put(key.toString(), object.get(key).toString()));
    }

    //for test
    public static void main(String[] args) throws ParseException {
        String body = "{\"msgId\": \"8600C5A3-C666-4E63-BFDB-52BCF557F938\", \"jiraId\": \"ERR002\"}";
        JSONParser parser = new JSONParser();
        JSONObject object = (JSONObject) parser.parse(body);
        final Map<String, String> headers = new HashMap<String, String>();
        object.keySet().forEach(key -> headers.put(key.toString(), object.get(key).toString()));
        System.out.println();
    }
}

Create bean

<bean class="org.mybean.JSONToHeadersBean" id="JSONToHeadersBean" name="JSONToHeadersBean"/>

And you can use it in route

<bean method="jsonToHeaders" ref="JSONToHeadersBean"/>
user_67840720

As an alternative you may parse JSON to HashMap and put it into a header:

.unmarshal().json(JsonLibrary.Jackson, java.util.Map.class)
.setHeader("params", simple("body"))

(requires camel-jackson dependency)

To access the stored values:

.log(LoggingLevel.INFO, "MsgId: ${header.params[msgId]}")
user_21735000
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