kudu scan java api

kudu 0.8.0版本支援scan來查詢一個地區內的資料，目前不支援根據主鍵get api，可關注issueKUDU-1235，小米冰琳兄在做。 根據range查詢

範例

KuduClient client = new KuduClient.KuduClientBuilder(KUDU_MASTER).build();List<String> projectColumns = new ArrayList<String>(1);projectColumns.add("id");projectColumns.add("name");projectColumns.add("age");KuduTable table = client.openTable(tableName);Schema schema = table.getSchema();PartialRow partialRow = schema.newPartialRow();partialRow.addInt("id", 1);PartialRow partialRow1 = schema.newPartialRow();partialRow1.addInt("id", 2);ColumnRangePredicate crp = new KuduScanner scanner = client.newScannerBuilder(table)            .setProjectedColumnNames(projectColumns)//指定輸出資料行            .lowerBound(partialRow)//指定下限（包含）            .exclusiveUpperBound(partialRow1)//指定上限（不包含）            .build();while (scanner.hasMoreRows()) {    RowResultIterator results = scanner.nextRows();    int i=0;    while (results.hasNext()) {        RowResult result = results.next();        System.out.println(i+" : "+result.getInt(0)+" "+result.getString(1)+" "+result.getInt(2));    }    break;}

根據判斷查詢

範例

...KuduPredicate kp = KuduPredicate.newComparisonPredicate(schema.getColumn("id"), KuduPredicate.ComparisonOp.EQUAL, 1);//建立predicateKuduScanner scanner = client.newScannerBuilder(table)                .readMode(AsyncKuduScanner.ReadMode.READ_AT_SNAPSHOT)//設定讀取快照模式                .setProjectedColumnNames(projectColumns)                .addPredicate(kp)//設定predicate                .snapshotTimestampMicros(Long.valueOf("1463388259000000"))//設定時間戳記                .build();...

注意，讀取的是設定時間戳記以前最近的資料。