With Microsoft® Word installed, one can use a COM brigde to
 open Microsoft® Word and control it from within a Java
 program to instantiate and print the template.

 This way, one does not have to write Java code to parse and
 interpret Microsoft® Word files.

 Otherwise, in order to instantiate a custom template (not a
 Microsoft® Word template) in Java one does not need a library
 for simple cases.

public class Main
{
 public static java.lang.String replace
 ( final java.lang.String template,
   final java.util.Map<java.lang.String,java.lang.String> map )
 { final java.lang.StringBuilder list =
   new java.lang.StringBuilder( "\\$(" );
   for( final java.lang.String key: map.keySet() )
   { list.append( key ); list.append( "|" ); }
   list.append( "[^\\s\\S])" );
   java.util.regex.Pattern pattern =
   java.util.regex.Pattern.compile( list.toString() );
   java.util.regex.Matcher matcher = pattern.matcher( template );
   final java.lang.StringBuffer stringBuffer = new java.lang.StringBuffer();
   while( matcher.find() )
   { final java.lang.String string = matcher.group( 1 );
     matcher.appendReplacement
     ( stringBuffer, map.get( string )); }
   matcher.appendTail( stringBuffer );
   return stringBuffer.toString(); }

 public static void main( final java.lang.String[] args )
 { final java.util.Map<java.lang.String,java.lang.String> map =
   new java.util.HashMap<java.lang.String,java.lang.String>();
   map.put( "user", "Mary" );
   map.put( "name", "Patricia" );
   java.lang.System.out.println
   ( replace( "Hello $user, my name is $name.", map ) ); }}