You can view class's JavaDoc and class name from the Auto-complete form. eXo IDE provides appropriate import statement into the file header automatically, if needed. There is a list of default packages for the Groovy code and so are imported explicitly:
java.lang
java.io
java.lang
java.math.BigDecimal
java.math.BigInteger
java.net
java.util
groovy.lang
groovy.util
