Package org.apache.commons.io.input

Class BoundedInputStream

java.lang.Object
java.io.InputStream
java.io.FilterInputStream
org.apache.commons.io.input.ProxyInputStream
org.apache.commons.io.input.BoundedInputStream
All Implemented Interfaces:
Closeable, AutoCloseable
public class BoundedInputStream extends ProxyInputStream
Reads bytes up to a maximum count and stops once reached.

To build an instance, see BoundedInputStream.AbstractBuilder.

By default, a BoundedInputStream is unbound; so make sure to call BoundedInputStream.AbstractBuilder.setMaxCount(long).

You can find out how many bytes this stream has seen so far by calling getCount(). This value reflects bytes read and skipped.

Using a ServletInputStream

A ServletInputStream can block if you try to read content that isn't there because it doesn't know whether the content hasn't arrived yet or whether the content has finished. Initialize an BoundedInputStream with the Content-Length sent in the ServletInputStream's header, this stop it from blocking, providing it's been sent with a correct content length in the first place.

Using NIO


 BoundedInputStream s = BoundedInputStream.builder()
   .setPath(Paths.get("MyFile.xml"))
   .setMaxCount(1024)
   .setPropagateClose(false)
   .get();

Using IO


 BoundedInputStream s = BoundedInputStream.builder()
   .setFile(new File("MyFile.xml"))
   .setMaxCount(1024)
   .setPropagateClose(false)
   .get();

Counting Bytes

You can set the running count when building, which is most useful when starting from another stream: 


 InputStream in = ...;
 BoundedInputStream s = BoundedInputStream.builder()
   .setInputStream(in)
   .setCount(12)
   .setMaxCount(1024)
   .setPropagateClose(false)
   .get();

Listening for the max count reached


 BoundedInputStream s = BoundedInputStream.builder()
   .setPath(Paths.get("MyFile.xml"))
   .setMaxCount(1024)
   .setOnMaxCount((max, count) -> System.out.printf("Max count %,d reached with a last read count of %,d%n", max, count))
   .get();
Since:
2.0
See Also: