Issue converting .json file to Map

Question

I'm having issues converting a simple JSON message into a Map

Example_1.json:

{"toAddress":"[email protected]",
"fromAddress":"[email protected]",
"subject":"Subject from JSON",
"body":"Body from JSON"}

Spring configuration:

<!-- Read file and output to filesIn channel -->
<int:channel id="filesIn" />
<int-file:inbound-channel-adapter id="filesReader"
                                  directory="file:/C:/data/inputDirectory"
                                  filename-pattern="*.json"
                                  channel="filesIn"
                                  prevent-duplicates="true">
    <int:poller id="poller" fixed-delay="5000" max-messages-per-poll="1" />
</int-file:inbound-channel-adapter> 

<file:file-to-string-transformer input-channel="filesIn" output-channel="strings"/>

<int:json-to-object-transformer input-channel="strings" output-channel="objectsOut" type="java.util.Map"/>

<int:object-to-map-transformer input-channel="objectsOut" output-channel="mapOut"/>

<int-file:outbound-channel-adapter channel="mapOut" directory="file:/C:/data/outputDirectory1" />


<!-- Activate logging -->

<int:channel id="filesIn">
    <int:interceptors>
        <int:wire-tap channel="LoggingChannel" />
    </int:interceptors>
</int:channel>

<int:channel id="strings">
    <int:interceptors>
        <int:wire-tap channel="LoggingChannel" />
    </int:interceptors>
</int:channel>

<int:channel id="objectsOut">
    <int:interceptors>
        <int:wire-tap channel="LoggingChannel" />
    </int:interceptors>
</int:channel>

<int:channel id="mapOut">
    <int:interceptors>
        <int:wire-tap channel="LoggingChannel" />
    </int:interceptors>
</int:channel>

<int:channel id="LoggingChannel" />
<int:service-activator input-channel="LoggingChannel" expression="@LOG.trace('Headers are: {}, Payload is: {} ', headers, payload)" />

<bean id="LOG" class="SafeLoggerFactory" factory-method="getLogger">
    <constructor-arg value="integrationEmailLogger"/>
</bean>

Error:

org.springframework.integration.handler.LoggingHandler] - org.springframework.messaging.MessageHandlingException: failed to write Message payload to file; nested exception is java.lang.IllegalArgumentException: unsupported Message payload type [java.util.HashMap], failedMessage=GenericMessage [payload={subject=Subject from JSON, [email protected], body=Body from JSON, [email protected]}, headers={file_originalFile=C:\data\inputDirectory\Example_1.json, id=be65b982-ef47-0207-2ec9-3fdb04837651, file_name=Example_1.json, timestamp=1575407244281}]

Essentially I would like to convert JSON text into a Map, so that I can use expressions such as payload.toAddress to send emails using an outbound-channel-adapter

Gary Russell Gary Russell · Accepted Answer · 2019-12-03T21:37:36

You should always include the full stack trace; a truncated stack trace is useless.

Why do you have an object-to-map-transformer? The json-to-object-transformer has already created a map for you; the o-t-m-t is redundant.

The file int-file:outbound-channel-adapter doesn't know how to handle a Map payload. That's where the failure is.

Issue converting .json file to Map

1 Answers