Java8之Predicate接口使用
优点:过滤条件可以不用写对应的if else条件
public static void main(String[] args) { List<MessageRecord> messageRecords = Lists.newArrayList(); for (int i = 0; i < 2; i++) { MessageRecord messageRecord = new MessageRecord(); messageRecord.setSourceSystemId("biz-rcs-cmc-demo"); Map<String, Object> map = new HashMap<>(); map.put(MessagePropertyNames.RETRY_ORIGIN_MSGID, i); messageRecord.setProperties(map); messageRecords.add(messageRecord); } for (int i = 0; i < 2; i++) { MessageRecord messageRecord = new MessageRecord(); messageRecord.setSourceSystemId("biz-rcs-cmc"); messageRecords.add(messageRecord); } for (int i = 0; i < 2; i++) { MessageRecord messageRecord = new MessageRecord(); messageRecord.setSourceSystemId("biz-rcs-cmc-test"); messageRecords.add(messageRecord); } List<MessageRecord> messageRecordList = conditionOrFilter(messageRecords, messageRecord -> "biz-rcs-cmc".equals(messageRecord.getSourceSystemId()), messageRecord -> { Integer retryOriginMsgId = messageRecord.getProperty(MessagePropertyNames.RETRY_ORIGIN_MSGID); return !ObjectUtils.isEmpty(retryOriginMsgId); }); messageRecordList.forEach(messageRecord -> { log.info("sourceSystemId:{}, _retryOriginMsgId:{}", messageRecord.getSourceSystemId(), messageRecord.getProperty(MessagePropertyNames.RETRY_ORIGIN_MSGID)); }); } /** * 过滤条件或的关系 * @param list * @param predicate * @param predicateTemp * @return */ public static List<MessageRecord> conditionOrFilter(List<MessageRecord> list, Predicate<MessageRecord> predicate, Predicate<MessageRecord> predicateTemp){ return list.stream().filter(predicate.or(predicateTemp)).collect(Collectors.toList()); } /** * 过滤条件与的关系 * @param list * @param predicate * @param predicateTemp * @return */ public static List<MessageRecord> conditionAndFilter(List<MessageRecord> list, Predicate<MessageRecord> predicate, Predicate<MessageRecord> predicateTemp){ return list.stream().filter(predicate.and(predicateTemp)).collect(Collectors.toList()); } /** * 过滤单个条件 * @param list * @param predicate * @return */ public static List<MessageRecord> conditionFilter(List<MessageRecord> list, Predicate<MessageRecord> predicate){ return list.stream().filter(predicate).collect(Collectors.toList()); }
美梦成真,变为事实。