How to resolve a Zlib issue — Java migration from 8 to 11 - spring-mvc

Question

I am working on upgrading Java version from 8 to 11 for an application (maven/spring-framework- no spring boot). The code compiles fine, war is deployed, and application is up and running.
But, it is unable to process incoming client requests. It's throwing java.io.EOFException unexpected end of zlib input stream java.
Below is the request the client sends to the Tomcat server where the Java application is deployed:
Hypertext Transfer Protocol
POST /xxxx/clients/events/inventory HTTP/1.1\r\n
content-encoding: deflate\r\n
User-Agent: Java/1.8.0_131\r\n
Host: xx.xx.xxx.xx:81\r\n
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2\r\n
Connection: keep-alive\r\n
Content-type: application/x-www-form-urlencoded\r\n
Transfer-Encoding: chunked\r\n
\r\n
[Full request URI: http://xx.xx.xxx.xx:81/xxxx/clients/events/inventory]
[HTTP request 1/1]
[Response in frame: 10]
HTTP chunked response
Content-encoded entity body (deflate): 147 bytes -> 183 bytes
File Data: 183 byte
HTML Form URL Encoded: application/x-www-form-urlencoded
Form item: "b4
{"Number":"1","EventType":"Inventory","ID":"3c65ec84-cfeb-4ab1-959d-ce8da7b5907c","EquipmentType":"Train","Timestamp":"1671523655021","Train":[{"SystemType":"Train"}],"System":"1"}" = ""
On the server side we have InflaterFilter and InflaterRequestWrapper around HttpServletRequestWrapper to handle the compressed data, and in the controller we have this method below:
#RequestMapping(value = { "inventory", "alarms" }, method = RequestMethod.POST)
#ResponseBody public ResponseEntity<HttpStatus> handleInventoryOrAlarmEvents(ServletInputStream is) {
return new ResponseEntity<HttpStatus>(service.handleEvents(is) ? HttpStatus.OK
: HttpStatus.INTERNAL_SERVER_ERROR);
}
handleEvents method:
#Override public boolean handleEvents(InputStream is) {
ThreadLocal<Boolean> success =
new ThreadLocal<Boolean>() {
/**
* #see ThreadLocal#initialValue()
*/
#Override protected Boolean initialValue() {
return true;
}
};
DispatchMessageExceptionListener exceptionListener = new DispatchMessageExceptionListener(success);
StringInputStream sis = new StringInputStream(is);
try {
String string = null;
while ((string = sis.readString()) != null) {
ClientEvent event = null;
try {
event = parser.parse(string);
if (event == null) {
LOGGER.error("-handleEvents, could not parse event={}", string);
continue;
}
LOGGER.debug("+handleEvents, incoming event={}", event);
if(event.hasProperty("BandwidthEconomyQuota")){
LOGGER.info("Received Fleet Counter for Train Id: {}", event.getString("System"));
}
eventManager.send(event, exceptionListener);
}
catch (Exception e) {
LOGGER.debug("Failed to handle event={}", event, e);
success.set(false);
}
} // end while
}
catch (Exception e) {
LOGGER.debug("Failed to handle all events.", e);
success.set(false);
}
finally {
IOUtil.close(is);
}
return exceptionListener.isSuccess();
} // end method handleEvents
The StringInputStream class:
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* Reads strings from an underlying input stream.
*
* #author Marco Soeima
* #version 2013/11/13
*/
public class StringInputStream extends FilterInputStream {
/**
* Creates a new {#link StringInputStream} object.
*
* #param is The input stream to wrap.
*/
public StringInputStream(InputStream is) {
super(is);
}
/**
* Reads the string size from the backing input stream.
*
* #return The string size.
*
* #throws IOException If an I/O error occurs.
*/
private int readSize() throws IOException {
int c = in.read();
if (c < 0) {
return -1;
}
StringBuilder buf = new StringBuilder();
while ((c != -1) && (c != '\n')) {
buf.append((char)c);
c = in.read();
}
return Integer.parseInt(buf.toString(), 16);
}
/**
* Fully reads the <code>size</code> number of bytes into a byte array.
*
* #param size The number of bytes to read.
*
* #return The byte array with the given bytes.
*
* #throws IOException If an I/O error occurs.
*/
private byte[] readFully(int size) throws IOException {
int read = 0;
int count = 0;
byte[] buf = new byte[size];
while ((count >= 0) && (read < size)) {
count = in.read(buf, read, size - read);
read += count;
}
return buf;
}
/**
* Reads a string from the underlying input stream.
*
* #return A string or <code>null</code> if no more string are available for reading.
*
* #throws IOException If an I/O error occurs.
*/
public String readString() throws IOException {
int size = readSize();
if (size < 0) {
return null;
}
return new String(readFully(size), "UTF-8");
}
}
I have googled many solutions. However I have not resolved the issue. Please help me with what is causing the issue and how to resolve this.
Note: I upgraded Tomcat from 7 to 9 along with Java from 8 to 11.
Thanks in advance.