java - 从 Hector QueryResult 对象中获取字符串

Question

我正在使用 Java Hector API 从 Cassandra 数据库检索数据，如下所示:

public static void retrieveData() {
    try {
        //Create a cluster object from your existing Cassandra cluster
        Cluster cluster = HFactory.getOrCreateCluster("Test Cluster", "localhost:9160");

        //Create a keyspace object from the existing keyspace we created using CLI
        Keyspace keyspace = HFactory.createKeyspace("TestDB", cluster);

        SliceQuery<String, String, String> sliceQuery = HFactory.createSliceQuery(keyspace, stringSerializer, stringSerializer, stringSerializer);
        sliceQuery.setColumnFamily("ClientHeaders").setKey("1234");
        sliceQuery.setRange("", "", false, 10);
        sliceQuery.setColumnNames("ip_address","uuid");
        QueryResult<ColumnSlice<String, String>> result = sliceQuery.execute();                 
        System.out.println("\nInserted data is as follows:\n" + result.get());   
    } catch (Exception ex) {
        System.out.println("Error encountered while retrieving data!!");
        ex.printStackTrace() ;
    }

所以我按照以下顺序查询检索到的值:

ColumnSlice([HColumn(ip_address=203.110.85.171), HColumn(uuid=a3363400-abfd-0130-e2cf-07b5c765964c)])

但是我想将结果提取到某个字符串变量(字符串 ip=ip_address 等)中并使用。但我不知道该怎么做？请帮忙。谢谢。

Answer 1

尝试这样做:

 if (result != null && result.get() != null) {
            List<HColumn<String, String>> resultCols = result.get().getColumns();
            for (HColumn<String, String> col : resultCols)
            {
               System.out.println(col.getValue());
            }