Why Premature EOF Error has occur, while reading CSV file using SpringBoot Scheduled Task

Below shows the relevant code segments. Is it related to connection close or Buffer memory.? (The file, which contains 50MB+ AND 65000+ Text Lines)

@Scheduled(cron = "0 0 9 * * *")
public void retrieveFile() throws IOException{
    try {
        RestTemplate restTemplate=new RestTemplate();
        String url="URL of the file, which contains 50MB+ AND 65000+ Text Lines";
        restTemplate.getMessageConverters().add(0, new StringHttpMessageConverter(Charset.forName("UTF-8")));
        URL targetFileUrl = new URL(url);
        URLConnection connection = targetFileUrl.openConnection();
        InputStream is = connection.getInputStream();
        handleFile(is);
    }catch (Exception e) {
        e.getMessage();
    }
}


public void handleFile(InputStream inputStream) throws IOException {
    BufferedReader reader = null;
    try {
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
        reader = new BufferedReader(inputStreamReader);
        String nextLine = null;
        while ((nextLine = reader.readLine()) != null) {
                //saving them in DB
            }
        }
        
    } catch (Exception ex) {
        ex.getMessage();//ERROR POPULATED FROM HERE
    } finally {
        if (reader != null) {
            reader.close();
        }
    }
}

Please advise on this.! Thanks.

Updated Please find here the Error Stack Trace. I've marked error lines from the source and mapped them with logs.

Error Stack Trace : java.io.IOException: Premature EOF
    at java.base/sun.net.www.http.ChunkedInputStream.readAheadBlocking(ChunkedInputStream.java:568)
    at java.base/sun.net.www.http.ChunkedInputStream.readAhead(ChunkedInputStream.java:612)
    at java.base/sun.net.www.http.ChunkedInputStream.read(ChunkedInputStream.java:699)
    at java.base/java.io.FilterInputStream.read(FilterInputStream.java:133)
    at java.base/sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(HttpURLConnection.java:3510)
    at java.base/sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
    at java.base/sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
    at java.base/sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
    at java.base/java.io.InputStreamReader.read(InputStreamReader.java:181)
    at java.base/java.io.BufferedReader.fill(BufferedReader.java:161)
    at java.base/java.io.BufferedReader.readLine(BufferedReader.java:326)
    at java.base/java.io.BufferedReader.readLine(BufferedReader.java:392)
    at com.blah.blah.blah.handleFile(FileOps.java:75)//This coding line -> ((nextLine = reader.readLine()) != null) {
    at com.blah.blah.blah.retrieveFile(FileOps.java:65)//This coding line -> handleFile(is);
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84)
    at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
    at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:95)
    at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:829)

The exception is thrown by the internal class sun.net.www.http.ChunkedInputStream. This class is used to read a chunk of http content whose length was declared at the beginning using the Content-Length HTTP header. However, the http content was incomplete, because it ended before the expected amount of bytes was read.

This is possibly caused by a bad http connection or a server that sends incomplete http content. Use a debugging tool such as Wireshark and examine the returned raw http content; look at the Content-Length and ensure that this many characters are available to read.