private static List parseBreeHeader()

in repository/service/src/main/java/org/apache/karaf/cave/repository/service/bundlerepository/ResourceBuilder.java [852:940]
75 lines of code
14 McCabe index (conditional complexity)

    private static List<Requirement> parseBreeHeader(String header, Resource resource) {
        List<String> filters = new ArrayList<String>();
        for (String entry : parseDelimitedString(header, ",")) {
            List<String> names = parseDelimitedString(entry, "/");
            List<String> left = parseDelimitedString(names.get(0), "-");

            String lName = left.get(0);
            Version lVer;
            try {
                lVer = Version.parseVersion(left.get(1));
            } catch (Exception ex) {
                // Version doesn't parse. Make it part of the name.
                lName = names.get(0);
                lVer = null;
            }

            String rName = null;
            Version rVer = null;
            if (names.size() > 1) {
                List<String> right = parseDelimitedString(names.get(1), "-");
                rName = right.get(0);
                try {
                    rVer = Version.parseVersion(right.get(1));
                } catch (Exception ex) {
                    rName = names.get(1);
                    rVer = null;
                }
            }

            String versionClause;
            if (lVer != null) {
                if ((rVer != null) && (!rVer.equals(lVer))) {
                    // Both versions are defined, but different. Make each of them part of the name
                    lName = names.get(0);
                    rName = names.get(1);
                    versionClause = null;
                } else {
                    versionClause = getBreeVersionClause(lVer);
                }
            } else {
                versionClause = getBreeVersionClause(rVer);
            }

            if ("J2SE".equals(lName)) {
                // J2SE is not used in the Capability variant of BREE, use JavaSE here
                // This can only happen with the lName part...
                lName = "JavaSE";
            }

            String nameClause;
            if (rName != null)
                nameClause = "(" + ExecutionEnvironmentNamespace.EXECUTION_ENVIRONMENT_NAMESPACE + "=" + lName + "/" + rName + ")";
            else
                nameClause = "(" + ExecutionEnvironmentNamespace.EXECUTION_ENVIRONMENT_NAMESPACE + "=" + lName + ")";

            String filter;
            if (versionClause != null)
                filter = "(&" + nameClause + versionClause + ")";
            else
                filter = nameClause;

            filters.add(filter);
        }

        if (filters.size() == 0) {
            return Collections.emptyList();
        } else {
            String reqFilter;
            if (filters.size() == 1) {
                reqFilter = filters.get(0);
            } else {
                // If there are more BREE filters, we need to or them together
                StringBuilder sb = new StringBuilder("(|");
                for (String f : filters) {
                    sb.append(f);
                }
                sb.append(")");
                reqFilter = sb.toString();
            }

            SimpleFilter sf = SimpleFilter.parse(reqFilter);
            return Collections.<Requirement>singletonList(new RequirementImpl(
                    resource,
                    ExecutionEnvironmentNamespace.EXECUTION_ENVIRONMENT_NAMESPACE,
                    Collections.singletonMap(ExecutionEnvironmentNamespace.REQUIREMENT_FILTER_DIRECTIVE, reqFilter),
                    Collections.<String, Object>emptyMap(),
                    sf));
        }
    }