title: How to handle null pointer and what is "null safe" way to code?
body: <p>I am a junior developer and I use java to do website development. 
  I know org.apache.common.lang.StringUtils is recommended because of its null safty. 
  But what is null safe or null safty exacty? 
  why the codes as follows is ugly?</p>
  
  <blockquote>
    <p>if( sth != null ) {
    ...
    } </p>
  </blockquote>