Kudu Java API 条件查询

        <!-- https:///artifact/org.apache.kudu/kudu-client -->
        <dependency>
            <groupId>org.apache.kudu</groupId>
            <artifactId>kudu-client</artifactId>
            <version>1.9.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.kudu</groupId>
            <artifactId>kudu-spark2_2.11</artifactId>
            <version>1.7.0</version>
        </dependency>

package src.main.sample;



import org.apache.kudu.ColumnSchema;
import org.apache.kudu.Schema;
import org.apache.kudu.client.*;

import java.util.ArrayList;
import java.util.List;

public class SelectKuduData2
{
    //select * from rawdata.event_wos_p1 where user_id = -1024924858009673815;
    private static String tableName = "event_wos_p1";

    //private static KuduClient client = new KuduClient.KuduClientBuilder("IP,IP,IP").defaultAdminOperationTimeoutMs(60000).build();


    // 获取需要查询数据的列
    private static List<String> projectColumns = new ArrayList<String>();

    private static KuduTable table;
    private static KuduScanner.KuduScannerBuilder builder;
    private static KuduScanner scanner;
    private static KuduPredicate predicate;

    public static void main(String[] args) throws KuduException
    {
        try
        {
            projectColumns.add("user_id"); //字段名
            projectColumns.add("day");
            table = client.openTable(tableName);

            // 简单的读取 newScannerBuilder(查询表)  setProjectedColumnNames(指定输出列)  build()开始扫描
//            KuduScanner scanner = client.newScannerBuilder(table).setProjectedColumnNames(projectColumns).build();

            builder = client.newScannerBuilder(table).setProjectedColumnNames(projectColumns);
            /**
             * 设置搜索的条件
             * 如果不设置，则全表扫描
             */
            //select * from 表名 where user_id = xxx;
             long userID = 123456789;
             //比较方法ComparisonOp：GREATER、GREATER_EQUAL、EQUAL、LESS、LESS_EQUAL
            predicate = predicate.newComparisonPredicate(table.getSchema().getColumn("user_id"),
                                                                KuduPredicate.ComparisonOp.EQUAL, userID);
 

            builder.addPredicate(predicate);
            // 开始扫描
            scanner = builder.build();
 
            while (scanner.hasMoreRows())
            {
                RowResultIterator results = scanner.nextRows();
                // 每次从tablet中获取的数据的行数
                int numRows = results.getNumRows();
                System.out.println("numRows count is : "   numRows);
                while (results.hasNext()) {
                    RowResult result = results.next();
                    long user_id = result.getLong(0);
                    int day = result.getInt(1);
                     System.out.println("user_id is : "   user_id   "  ===  day: "   day );
                }
                System.out.println("--------------------------------------");
            }
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        finally 
        {
            scanner.close();
            client.close();
        }
    }
}

来源：http://www./content-1-194801.html