Solr集羣的連接，查詢及遊標的使用

ps:需要注意的點都用註釋標明瞭

一，連接

   /**
     * 創建連接
     * @return
     * @throws IOException
     * @throws SolrServerException
     */
    public SolrClient connectSolr() throws IOException, SolrServerException {
        //連接zookeeper
        CloudSolrClient cloudSolrClient = new CloudSolrClient("ip:zookeeper端口號");

        cloudSolrClient.setDefaultCollection("paper6.1");
        cloudSolrClient.connect();
        return cloudSolrClient;
    }

二，構造查詢條件

   /**
     * 構造查詢條件
     * @return
     */
    public SolrQuery buildSearchParam(){
        SolrQuery solrQuery = new SolrQuery();
        solrQuery.setQuery("stringIS_sysSubType:R03");//q
        solrQuery.setFilterQueries("auto_stringITMS_keyword:zh-cn|鋼鐵");//fq
        solrQuery.setFields("id,type,stringIS_sysSubType,auto_stringITMS_keyword");//fl
        solrQuery.addField("dateIS_date");//新增fl項
        return solrQuery;
    }

三，普通查詢

  /**
     * 普通查詢
     */
    public void simpleSearch(){
        //1.構造查詢條件
        SolrQuery solrQuery = this.buildSearchParam();
        solrQuery.setSort("dateIS_date ", SolrQuery.ORDER.asc);//sort
        solrQuery.setStart(0);
        solrQuery.setRows(1);

        //2.查詢
        QueryResponse queryResponse = null;
        try {
            queryResponse = this.connectSolr().query(solrQuery);
        } catch (Exception e) {
            e.printStackTrace();
        }

        //3.遍歷結果
        //3.1 map遍歷
        SolrDocumentList results = queryResponse.getResults();//SolrDocumentList本質是List<Map>結構
        Iterator<SolrDocument> iterator = results.iterator();
        while (iterator.hasNext()) {
            SolrDocument document = iterator.next();
            Set<Map.Entry<String, Object>> entries = document.entrySet();
            for (Map.Entry<String, Object> entry : entries) {
                System.out.println(entry.getKey() + ":" + entry.getValue());
            }
        }

       //3.2  List轉json
        SolrDocumentList docs = queryResponse.getResults();
        String json = new Gson().toJson(docs);//list轉json 
        System.out.println(json);

        //3.3 map轉json
        StringBuffer sb = new StringBuffer("[");
        while(iterator.hasNext()) {
            SolrDocument document = iterator.next();
            JSONObject jsonObject = new JSONObject(document);
            String string = jsonObject.toString();
            sb.append(string);
            sb.append(",");
        }
        sb.deleteCharAt(sb.lastIndexOf(","));
        sb.append("]");
        System.out.println(sb.toString());
    }

四，遊標查詢

/**
     * 遊標查詢
     */
    public void cursorSearch() throws IOException, SolrServerException {
        SolrQuery solrQuery = this.buildSearchParam();
        solrQuery.setSort("id", SolrQuery.ORDER.asc);//如果使用遊標查詢，那麼必須根據主鍵排序
        solrQuery.setRows(2);//注意：使用遊標方式，不能設置start
        String beginCursor = CursorMarkParams.CURSOR_MARK_START;//* 遊標開始的標誌
        boolean flag = true;
        while(flag){
            solrQuery.setParam(CursorMarkParams.CURSOR_MARK_PARAM,beginCursor);
            QueryResponse queryResponse = this.connectSolr().query(solrQuery);
            SolrDocumentList docs = queryResponse.getResults();//獲取查詢結果
            String json = new Gson().toJson(docs);
            System.out.println(json);
            String nextCursorMark = queryResponse.getNextCursorMark();//獲取下一個遊標值
            if (beginCursor.equalsIgnoreCase(nextCursorMark)){ //如果值獲取完畢，那麼返回的遊標值就和上次的一樣
                flag = false;
            }
            beginCursor = nextCursorMark;
        }
    }