The Java interface to the dtSearch Engine is based on the Java Native Interface (JNI). Therefore, both the Java classes and a platform-specific binary executable are needed to use it.
The Java classes are in examples\java\classes\dtSearchEngine.jar, which must be on the CLASSPATH. Adding the dtSearch Engine examples/java/classes folder to the CLASSPATH, or copying its contents to a folder on the CLASSPATH, will make these classes available in Java.
For information on setting up the platform-specific binary executable, please see:
Java version or later 1.4.1 is required.
For general information on using the dtSearch Engine API, such as the search request syntax, procedures for building and maintaining indexes, and options settings, see the Overviews section in dtSearchApiRef.chm.
Additional developer documentation is posted on the 
dtSearch technical support site.