Java Doc for NullReader.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 Reader where the contents don't matter.

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

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

 public class TestReader extends NullReader {
 public TestReader(int size) {
 super(size);
 }
 protected char processChar() {
 return ... // return required value here
 }
 protected void processChars(char[] chars, int offset, int length) {
 for (int i = offset; i < length; i++) {
 chars[i] = ... // set array value here
 }
 }
 }
 

This implementation returns zero. This implementation always returns zero.

This implementation leaves the character array unchanged.
Parameters:
  chars - The character array
Parameters:
  offset - The offset to start at.
Parameters:
  length - The number of characters.