Importing libraries for using Java Exec

Problem:
Want to use Java Exec, is it resulting in error?

Solution:
Add following libraries to your .bpel code:
<bpelx:exec import="java.util.*"/>
<bpelx:exec import="java.lang.*"/>
<bpelx:exec import="java.math.*"/>
<bpelx:exec import="java.io.*"/>
<bpelx:exec import="com.collaxa.common.util.Base64Decoder"/>
<bpelx:exec import="com.collaxa.common.util.Base64Encoder"/>