What is the best way to validate JSON input in AEM?

[HanL1]

Hi 

I am trying to validate JSON input in SlingHttpServletRequest in AEM, I tried to use JSON Schema and JSON Schema validator but it doesn't compile with AEM. Every time I use the JSON validator I got an error on the AEM page, all the function buttons are gone except the "Create" button.

I found that the root cause is because I used this JSON schema validator:

<dependency>
    <groupId>com.github.fge</groupId>
    <artifactId>json-schema-validator</artifactId>
    <version>2.2.6</version>
</dependency>

It breaks the app and someone of the OSGi components fail to start. Not sure why.

Here's the code:

    private String jsonSchema ="{\\\"$schema\\\":\\\"https://json-schema.org/draft/2019-09/schema\\\",\\\"$id\\\":\\\"http://example.com/example.json\\\",\\\"type\\\":\\\"object\\\",\\\"default\\\":{},\\\"title\\\":\\\"RootSchema\\\",\\\"properties\\\":{\\\"startDate\\\":{\\\"type\\\":\\\"string\\\",\\\"default\\\":\\\"\\\",\\\"title\\\":\\\"ThestartDateSchema\\\",\\\"examples\\\":[\\\"2021-01-01\\\"],\\\"format\\\":\\\"date\\\"},\\\"endDate\\\":{\\\"type\\\":\\\"string\\\",\\\"default\\\":\\\"\\\",\\\"title\\\":\\\"TheendDateSchema\\\",\\\"examples\\\":[\\\"2021-12-27\\\"],\\\"format\\\":\\\"date\\\"},\\\"governingBodyId\\\":{\\\"type\\\":\\\"string\\\",\\\"default\\\":\\\"\\\",\\\"title\\\":\\\"ThegoverningBodyIdSchema\\\",\\\"examples\\\":[\\\"a6f7A0000001B08QAE\\\"],\\\"pattern\\\":\\\"^[a-zA-Z0-9]{0,256}$\\\"},\\\"sourceId\\\":{\\\"type\\\":\\\"string\\\",\\\"default\\\":\\\"\\\",\\\"title\\\":\\\"ThesourceIdSchema\\\",\\\"examples\\\":[\\\"\\\"],\\\"pattern\\\":\\\"^[a-zA-Z0-9]{0,256}$\\\"},\\\"courseId\\\":{\\\"type\\\":\\\"string\\\",\\\"default\\\":\\\"\\\",\\\"title\\\":\\\"ThecourseIdSchema\\\",\\\"examples\\\":[\\\"\\\"],\\\"pattern\\\":\\\"^[a-zA-Z0-9]{0,256}$\\\"},\\\"useCompletionDate\\\":{\\\"type\\\":\\\"boolean\\\",\\\"default\\\":false,\\\"title\\\":\\\"TheuseCompletionDateSchema\\\",\\\"examples\\\":[true]}},\\\"examples\\\":[{\\\"startDate\\\":\\\"2021-01-01\\\",\\\"endDate\\\":\\\"2021-12-27\\\",\\\"governingBodyId\\\":\\\"a6f7A0000001B08QAE\\\",\\\"sourceId\\\":\\\"\\\",\\\"courseId\\\":\\\"\\\",\\\"useCompletionDate\\\":true}]}";
        String JsonData = IOUtils.toString(request.getInputStream(),"UTF-8");

        JsonNode dataNode = JsonLoader.fromString(JsonData);
        JsonNode schemaNode = JsonLoader.fromString(jsonSchema);
        JsonSchema schema = JsonSchemaFactory.byDefault().getJsonSchema(schemaNode);
        ProcessingReport processingReport = schema.validate(dataNode);
        if(!processingReport.isSuccess()){
        	log.error("Input JSON parameters don't match with the required pattern");
        	return;
        }

I also tried a different JSON schema validator library but still the same error.

If AEM doesn't compile with the JSON schema validator, what methods should I use to validate the JSON input (such as format, length etc.)?

Thanks

[ArpitVarshney]

Hi @HanL1 

Have you verified after deploying the code, whether your bundles are active or not? Please validate the /system/console/bundles.

If bundles are not active and the added jar is not getting resolved that means the given dependency is not available as a bundle in the target AEM.

You can follow the solution to this question if it is the same issue https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/aws-sdk-dependencies-are-n...

Regards,

Arpit Varshney

[HanL1]

I tried the method in that link but still the same error

[BrijeshYadav]

AEM provide inbuild JSON api for json parsing which perform validations as well.

 com.google.gson.JsonParser

[HanL1 · Accepted solution]

Can I use it this way? 

    private boolean isJson(String str) {
    	try {
    		JsonParser parser = new JsonParser();
    		parser.parse(str);
    		return true;
    	}catch(Exception e) {
    		return false;
    	}
    }

If an exception been thrown out, means the input JSON data is wrong, otherwise it's correct.

[BrijeshYadav]

Yes @HanL1