title: Java best practice: Class with only static methods
body: <p>I have an application where I have a class called <code>PlausibilityChecker</code>. This class has only static methods, like <code>checkZipcodeFormat</code> or <code>checkMailFormat</code>. I use them in my GUI classes to check the input before sending it to the lower layer.</p>
  
  <p>Is this good practice? I thought I'd go with only static methods so that I don't have to care about passing an instance to the GUI classes or having an instance field in each gui class that doesn't reference a gui object.</p>
  
  <p>I noticed that the <code>Files</code> class of <code>Java NIO</code> has only static methods so I assume this can't be that horribly wrong.</p>