Regarding NoClassDefFoundError
<p>I have used the isEmpty and isBlank methods of apache's StringUtils Class. These methods worked in a fine manner, after couple of weeks suddenly i got the error </p>

<p><strong>java.lang.NoClassDefFoundError: org.apache.commons.lang3.StringUtils</strong></p>

<p>I was confused why this error happened suddenly.It would be fine if anyone help me to understand this suddenly happened.</p>

<p>People Saying that apache might have changed the definitionin their JAR file, is it a right one,i really confused why this suddenly happened , i removed the old jar from my build path and downloaded the same version of New Jar and added it to Build path, then this issue is resloved.</p>

<p>It is happening in the Market Code , there's no interaction with ADT and market code</p>

<p>so really confused on this issue?</p>
