未完 Guava

集合工具：

引用

                List<String> companyNames = Lists.transform(companyList, new Function<Company, String>() {
                    public String apply(Company input) {
                        return input.getName();
                    }});

Map<Integer, User> filteredNewMembers = Maps.filterKeys(rawNewMembers, Predicates.in(filteredNewMemberIds));

                    Map<Integer, User> newMembers4CurUser = Maps.filterValues(newMembers, new Predicate<User>() {

                        @Override
                        public boolean apply(User newMember) {
                            return compare(provinceCode, newMember.getProvinceCode())
                                    && compare(cityStr, newMember.getCityStr())
                                    && compare(industryCode, newMember.getIndustryCode());
                        }

                        private boolean compare(String str1, String str2) {
                            if(StringUtils.isBlank(str1)) {
                                return true;
                            } else {
                                if(str1.equals(str2)) {
                                    return true;
                                } else {
                                    return false;
                                }
                            }
                        }
                    });

                Collections2.filter(recCompanyItems, new Predicate<CompanyItemVO>() {
                    @Override
                    public boolean apply(CompanyItemVO item) {
                        if (excludedCompanyIds.contains(item.getCompanyId())) {
                            return false;
                        }
                        return true;
                    }
                }));

OR

                Iterables.filter(recCompanyItems, new Predicate<CompanyItemVO>() {
                    @Override
                    public boolean apply(CompanyItemVO item) {
                        if (excludedCompanyIds.contains(item.getCompanyId())) {
                            return false;
                        }
                        return true;
                    }
                }));

Multimaps:
http://java.dzone.com/articles/multimaps-google-guava


Bidirectional Maps:
http://java.dzone.com/articles/guavas-bidirectional-maps