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)

CodePudding user response：

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.