Testing OutOfMemoryError with StringBuilder.

gistfile1.java

@Test
public void shouldGetOutOfMemoryErrorUsingStringBufferButNotUsingStringWritter(){
  int stringBuilderCapacity = 1024;
  StringBuilder stringBuilder = new StringBuilder(stringBuilderCapacity);
  String randomString = new BigInteger(stringBuilderCapacity++, new SecureRandom()).toString(32);
  try {
    while (true) {
      stringBuilder.append(randomString);
      stringBuilderCapacity *= 2;
    }
  } catch (OutOfMemoryError outOfMemoryError) {
    StringWriter stringWriter = new StringWriter();
    int stringWritterSize = 0;
    while(stringWritterSize < stringBuilderCapacity){
      stringWriter.write(randomString);
      stringWritterSize += randomString.length();
    }
    
    assertTrue(stringWritterSize >= stringBuilderCapacity);
    }
}