Spring RestTemplate gives $InternalServerError: 500 null. Same works in POSTMAN and for SMALL FILES

Question

I have a Spring batch application which does the below operations,

1. Read a file from AmazonS3 bucket.
2. Write it to local
3. Zip the file and send to Rest API as byte array (API accepts byte[])

when the job runs for small Files (below 2 MB), it is working fine and I am getting the response from API But when it is trying to hit large files, API throws below exception

org.springframework.web.client.HttpServerErrorException$InternalServerError: 500 null

Same large file if I hit through POSTMAN, I am getting proper response.

My Rest call is as below

       ClientHttpRequestFactory requestFactory = new     
              
      HttpComponentsClientHttpRequestFactory(HttpClients.createDefault());

    RestTemplate restTemplate = new RestTemplate(requestFactory);
        URI uri = new URI(submitUrl);
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.MULTIPART_FORM_DATA);
            MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
            
            body.add("inputDoc", byteArray);
            body.add("metaData", createOcrSubmitMap(fileName));
            HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<>(body, headers);
            ResponseEntity<String> response = restTemplate.postForEntity(uri, requestEntity, String.class);

Note: I am able to write this byte[] to a file and can open and see the file correctly.

The same set of code works fine with small files!!

What would went wrong with large files??

Complete stack trace

org.springframework.web.client.HttpServerErrorException$InternalServerError: 500 at org.springframework.web.client.HttpServerErrorException.create(HttpServerErrorException.java:79) at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:124) at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:102) at org.springframework.web.client.ResponseErrorHandler.handleError(ResponseErrorHandler.java:63) at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:778) at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:736) at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:710) at org.springframework.web.client.RestTemplate.postForEntity(RestTemplate.java:463) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:749) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:295) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688) at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:407) at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:331) at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140) at org.springframework.batch.core.step.tasklet.TaskletStep$2.doInChunkContext(TaskletStep.java:273) at org.springframework.batch.core.scope.context.StepContextRepeatCallback.doInIteration(StepContextRepeatCallback.java:82) at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:375) at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215) at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:145) at org.springframework.batch.core.step.tasklet.TaskletStep.doExecute(TaskletStep.java:258) at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:203) at org.springframework.batch.core.job.SimpleStepHandler.handleStep(SimpleStepHandler.java:148) at org.springframework.batch.core.job.AbstractJob.handleStep(AbstractJob.java:399) at org.springframework.batch.core.job.SimpleJob.doExecute(SimpleJob.java:135) at org.springframework.batch.core.job.AbstractJob.execute(AbstractJob.java:313) at org.springframework.batch.core.launch.support.SimpleJobLauncher$1.run(SimpleJobLauncher.java:144) at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:50) at org.springframework.batch.core.launch.support.SimpleJobLauncher.run(SimpleJobLauncher.java:137) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:343) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) at org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration$PassthruAdvice.invoke(SimpleBatchConfiguration.java:127) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) at com.sun.proxy.$Proxy94.run(Unknown Source) at com.test.batch.config.JobLauncherConfig.jjob1(JobLauncherConfig.java:56) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84) at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:93) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)

Exception is thrown at:

ResponseEntity<String> response = restTemplate.postForEntity(uri, requestEntity, String.class);

Answer 1

Issue resolved. Instead of passing the byte[] as it is, we should pass it as ByteArrayResource.

        MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
        ByteArrayResource contentsAsResource = new ByteArrayResource(byteArray){
            @Override
            public String getFilename() {
                return fileName;
            }
        };
        body.add("inputDoc", contentsAsResource);
        body.add("metaData", createOcrSubmitMap(fileName));