使用java操作kudu

使用maven导入kudu

<dependency>
  <groupId>org.apache.kudu</groupId>
  <artifactId>kudu-client</artifactId>
  <version>1.6.0</version>
</dependency>

使用java创建Kudu表

public class CreateTable {
    private static ColumnSchema newColumn(String name, Type type, boolean iskey) {
        ColumnSchema.ColumnSchemaBuilder column = new ColumnSchema.ColumnSchemaBuilder(name, type);
        column.key(iskey);
        return column.build();
    }
    public static void main(String[] args) throws KuduException {
        // master地址
        final String masteraddr = "hadoop01,hadoop02,hadoop03";
        // 创建kudu的数据库链接
        KuduClient client = new KuduClient.KuduClientBuilder(masteraddr).defaultSocketReadTimeoutMs(6000).build();

        // 设置表的schema
        List<ColumnSchema> columns = new LinkedList<ColumnSchema>();
/**
与 RDBMS 不同，Kudu 不提供自动递增列功能，因此应用程序必须始终在插入期间提供完整的主键
*/
        columns.add(newColumn("CompanyId", Type.INT32, true));
        columns.add(newColumn("WorkId", Type.INT32, false));
        columns.add(newColumn("Name", Type.STRING, false));
        columns.add(newColumn("Gender", Type.STRING, false));
        columns.add(newColumn("Photo", Type.STRING, false));
        Schema schema = new Schema(columns);
        //创建表时提供的所有选项
        CreateTableOptions options = new CreateTableOptions();
        // 设置表的replica备份和分区规则
        List<String> parcols = new LinkedList<String>();
        parcols.add("CompanyId");

        //设置表的备份数
        options.setNumReplicas(1);
        //设置range分区
        options.setRangePartitionColumns(parcols);
        //设置hash分区和数量
        options.addHashPartitions(parcols, 3);
        try {
            client.createTable("PERSON", schema, options);
        } catch (KuduException e) {
            e.printStackTrace();
        }
        client.close();
    }
}

使用java删除Kudu表

public class DropTable {
    public static void main(String[] args) throws KuduException {
        // master地址
        final String masteraddr = "hadoop01,hadoop02,hadoop03";
        // 创建kudu的数据库链接
        KuduClient client = new KuduClient.KuduClientBuilder(masteraddr).defaultSocketReadTimeoutMs(6000).build();
        client.deleteTable("PERSON");
        client.close();
    }
}

使用java插入数据到Kudu

public class InsertRow {
    public static void main(String[] args) throws KuduException {
        // master地址
        final String masteraddr = "hadoop01,hadoop02,hadoop03";
        // 创建kudu的数据库链接
        KuduClient client = new KuduClient.KuduClientBuilder(masteraddr).build();
        // 打开表
        KuduTable table = client.openTable("PERSON");
        // 创建写session,kudu必须通过session写入
        KuduSession session = client.newSession();
        // 采取Flush方式 手动刷新
        session.setFlushMode(FlushMode.MANUAL_FLUSH);
        session.setMutationBufferSpace(3000);
        for (int i = 1; i < 10; i++) {
            Insert insert = table.newInsert();
            // 设置字段内容
            insert.getRow().addInt("CompanyId", i);
            insert.getRow().addInt("WorkId", i);
            insert.getRow().addString("Name", "lisi" + i);
            insert.getRow().addString("Gender", "male");
            insert.getRow().addString("Photo", "person" + i);
            session.flush();
            session.apply(insert);
        }
        session.close();
        client.close();
    }
}

使用java查询Kudu中的数据

public class FindRow {
    public static void main(String[] args) throws KuduException {
        //master地址
        final String masteraddr = "hadoop01,hadoop02,hadoop03";
        //创建kudu的数据库链接
        KuduClient client = new KuduClient.KuduClientBuilder(masteraddr).defaultSocketReadTimeoutMs(6000).build();
        //打开表
        KuduTable table = client.openTable("PERSON");
        KuduScannerBuilder builder = client.newScannerBuilder(table);
        /**
         * 设置搜索的条件
         * 如果不设置，则全表扫描
         */
        KuduPredicate predicate = KuduPredicate.newComparisonPredicate(table.getSchema().getColumn("CompanyId"),
                KuduPredicate.ComparisonOp.EQUAL, 1);
        builder.addPredicate(predicate);
        // 开始扫描
        KuduScanner scaner = builder.build();
        while (scaner.hasMoreRows()) {
            RowResultIterator iterator = scaner.nextRows();
            while (iterator.hasNext()) {
                RowResult result = iterator.next();
                /**
                 * 输出行
                 */
                System.out.print("CompanyId:" + result.getInt("CompanyId") +"   ");
                System.out.print("Name:" + result.getString("Name") +"  ");
                System.out.print("Gender:" + result.getString("Gender")+"    ");
                System.out.print("WorkId:" + result.getInt("WorkId") +"  ");
                System.out.println("Photo:" + result.getString("Photo")+"    ");
            }
        }
        scaner.close();
        client.close();
    }
}

使用java更改Kudu表数据

public class UpdateTable {
    public static void main(String[] args) {
        // master地址
        final String masteraddr = "hadoop01,hadoop02,hadoop03";
        // 创建kudu的数据库链接
        KuduClient client = new KuduClient.KuduClientBuilder(masteraddr).build();
        // 打开表
        KuduSession session = null;
        try {
            KuduTable table = client.openTable("PERSON");
            session = client.newSession();
            session.setFlushMode(SessionConfiguration.FlushMode.AUTO_FLUSH_SYNC);
            //更新数据
            Update update = table.newUpdate();
            PartialRow row1 = update.getRow();
            row1.addInt("CompanyId",1);
            row1.addString("Name","di");
            session.apply(update);
        } catch (KuduException e) {
            e.printStackTrace();
        }finally {
            try {
                session.close();
            } catch (KuduException e) {
                e.printStackTrace();
            }
        }
    }
}

使用java删除Kudu中指定行数据

public class DeleteRow {
    public static void main(String[] args) throws KuduException {
        // master地址
        final String masteraddr = "hadoop01,hadoop02,hadoop03";
        // 创建kudu的数据库链接
        KuduClient client = new KuduClient.KuduClientBuilder(masteraddr).build();
        // 打开表
        KuduTable table = client.openTable("PERSON");
        // 创建写session,kudu必须通过session写入
        KuduSession session = client.newSession();
        final Delete delete = table.newDelete();
        //TODO 注意：行删除和更新操作必须指定要更改的行的完整主键;
        delete.getRow().addInt("CompanyId" , 5);
        session.flush();
        session.apply(delete);
        session.close();
        client.close();
    }
}