public Set getRootTableNames()

in rdb/src/main/java/org/apache/tuscany/das/rdb/config/wrapper/MappingWrapper.java [627:664]

33 lines of code
9 McCabe index (conditional complexity)


	public Set getRootTableNames() {
		if (this.logger.isDebugEnabled()) {
			this.logger.debug("Getting root tables");
		}
		if (rootTableNames == null) {
			rootTableNames = new HashSet();
			if (config == null) return rootTableNames;
			// parse all relationships
			Set allParents = new HashSet();
			Set allChildren = new HashSet();
			Iterator i = getConfig().getRelationship().iterator();
			while (i.hasNext()) {
				Relationship r = (Relationship) i.next();
				String parent = r.getPrimaryKeyTable();
				String child = r.getForeignKeyTable();
				if (parent.equals(child)) {
					// self-relationship
					// do not add to all children list to allow root detection
					allParents.add(parent);
				} else {
					allParents.add(parent);
					allChildren.add(child);
				}
			}
			// find roots (depth 0)
			// roots are tables that are present in the parents set, but not in the children set
			for (Iterator itParents = allParents.iterator(); itParents.hasNext(); ) {
				String parent = (String) itParents.next();
				if (!allChildren.contains(parent)) {
					rootTableNames.add(parent);
				}
			}
		}
		if (this.logger.isDebugEnabled()) {
			this.logger.debug(rootTableNames);
		}
		return rootTableNames;
	}