Java Doc for NullInputStream.java in  » Library » apache-common-IO » org » apache » commons » io » input » Java Source Code / Java DocumentationJava Source Code and Java Documentation

This implementation provides a light weight object for testing with an InputStream where the contents don't matter.

One use case would be for testing the handling of large InputStream as it can emulate that scenario without the overhead of actually processing large numbers of bytes - significantly speeding up test execution times.

This implementation returns zero from the method that reads a byte and leaves the array unchanged in the read methods that are passed a byte array. If alternative data is required the processByte() and processBytes() methods can be implemented to generate data, for example:

 public class TestInputStream extends NullInputStream {
 public TestInputStream(int size) {
 super(size);
 }
 protected int processByte() {
 return ... // return required value here
 }
 protected void processBytes(byte[] bytes, int offset, int length) {
 for (int i = offset; i < length; i++) {
 bytes[i] = ... // set array value here
 }
 }
 }
 

This implementation returns zero. This implementation always returns zero.

This implementation leaves the byte array unchanged.
Parameters:
  bytes - The byte array
Parameters:
  offset - The offset to start at.
Parameters:
  length - The number of bytes.