Example 1. Creating a Topic Map

	[1]  TopicMapSystemFactory   tSystemFactory  =   TopicMapSystemFactory.newInstance();
	[2]  TopicMapSystem tSystem 	=	tSystemFactory.newTopicMapSystem();
	[3]  TopicMap tm 		=	tSystem.createTopicMap("http://www.tmapi.org/examples/exampletm");
    

In line 1 and 2 a TopicMapSystemFactory and a TopicMapSystem are instantiated. For a deeper look on whats happening here, please go to the the section called “TopicMapSystem and TopicMapSystemFactory” In line 3 a topic map with the baseLocator "http://www.tmapi.org/examples/exampletm" is created. Now you can work with this org.tmapi.core.TopicMap instance.

	[4]  Topic t1	= tm.createTopic();
	[5]  t1.createTopicName("hello",null);
	[6]  Topic t2	= tm.createTopic();
	[7]  t2.createTopicName("world",null);	
    

In line 4 a topic is being created inside the topic map. Line 5 adds the TopicName "hello". This topic name has no scope, which is indicated by a given null parameter to the method createTopicName(String Value, Set scope). If you want to scope a topic name, you have to give a set of topics as the second parameter. Lines 6 and 7 create a second topic.

        [8]  Association a   = tm.createAssociation();
        [9]  a.createAssociationRole(t1, null);
        [10] a.createAssociationRole(t2, null);    
    

In line 8 an org.tmapi.core.Association is created. Line 9 and 10 are adding association roles to this association. The null as second parameter to the method createAssociationRole(Topic player, Topic type) indicates that the created association role is untyped.

    
        [11]  Iterator itt = tm.getTopics().iterator();
        [12]  while(itt.hasNext()){
        [13]    Topic t     = (Topic)itt.next();
        [14]    printTopicNames(t);
        [15]  }
    

In line 11 we get an Iterator over all topics in the topic map. In the lines 12-15 we iterate over all topics and use the method printTopicNames(Topic t) to print all topic names of one topic. The implementation of this method can be seen in the examples/example1.java file.

    
        [16]  Iterator ita = tm.getAssociations().iterator();
        [17]  while(ita.hasNext()){
        [18]      Association as   = (Association)ita.next();
        [19]      java.util.Iterator itr = as.getAssociationRoles().iterator();
        [20]      while(itr.hasNext()){
        [21]          AssociationRole m = (AssociationRole)itr.next();
        [22]          printTopicNames(m.getPlayer());                
        [23]      }
        [24]  }     
    

In line 16 we get an Iterator over all associations in the topic map. Beginning in the line 17 we iterate over all associations. In line 19 we get an iterator over all association roles of this association. Beginning in line 20 we iterate over all association roles and use the method printTopicNames(Topic t) to print all topic names of the role playing topic.