Overriding jar files on static classpath

I'm trying to get the AWS SDK jar file to work in matlab. I started by trying to simply import it and use it. When I do, it sort of works, but on every write I get this error:

Java exception occurred:
java.lang.IllegalStateException: Content has been consumed
  at org.apache.http.entity.BasicHttpEntity.getContent(BasicHttpEntity.java:84)
  at org.apache.http.conn.BasicManagedEntity.getContent(BasicManagedEntity.java:89)
  at com.amazonaws.http.AmazonHttpClient.executeHelper(AmazonHttpClient.java:452)
  at com.amazonaws.http.AmazonHttpClient.execute0(AmazonHttpClient.java:266)
  at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:236)
  at com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:3104)
  at com.amazonaws.services.s3.AmazonS3Client.putObject(AmazonS3Client.java:1233)
  at edu.xxxxx.aws.S3_Uploader.upload(S3_Uploader.java:31)

So I wrote a simple java class outside matlab to try to use my own version of the httpcore jar file. It works fine in eclipse, but if i import and run in matlab i get the same error. There is a httpcore jar file on the static classpath that seems to be getting used instead of the one I'm adding to the dynamic classpath, but it apparently is incompatible. Is there any way to get around this?

[Ameya Deoras]

I commented out that JAR file ($matlabroot/java/jarext/axis2/httpcore.jar) in @matlabroot/toolbox/local/classpath.txt and confirmed that it fixes the issues. I'm sure this is not recommended as it will cause other bad things to happen, so try this at your own risk.