Examples of org.kiji.schema.KijiRowData

org.kiji.schema.KijiRowData
the value stored in the column named 'info:name' with a timestamp of 42. final String name = row.getValue("info", "name", 42L);
We also provide additional methods for accessing data stored withing a row. See the documentation below for methods with the name 'get*' for more information.

Checking for existence of cells

Since rows within a Kiji table may not contain all the columns defined within a layout we need a way to check this in code. KijiRowData contains several methods to help with this:
```
  final KijiRowData row = myTableReader.get(myEntityId, myDataRequest); if (row.containsColumn("info", "name")) { // Now that we know the cell exists, read the value. final String name = row.getMostRecentValue("info", "name"); } if (row.containsCell("info", "name", 42L)) { // Now that we know that this cell exists at the timestamp of 42. final String name = row.getValue("info", "name", 42L); }  
```
Dealing with large rows

Rows in Kiji tables may contain large amounts of data. In some cases, this is caused by storing many versions of a cell with different timestamps in a row. This can become a problem when the size of a row/cell exceeds the amount of RAM available. To deal with large rows, you may use paging through a {@link KijiPager}. When paging is enabled on a column, cells from that column may only be accessed through {@link #getPager(String)} and {@link #getPager(String,String)}. See the documentation for {@link KijiPager} for more information.

    final KijiDataRequest dataRequest = KijiDataRequest.builder()
        .addColumns(ColumnsDef.create().withMaxVersions(2).add("family", "column"))
        .build();


    // Try this as a get.
    KijiRowData rowData = mReader.get(mEntityId, dataRequest);
    String s = rowData.getValue("family", "column", 0L).toString();
    assertEquals(s, "Value at timestamp 0.");


    // Delete the cell and make sure that this value is missing.
    mWriter.deleteCell(mEntityId, "family", "column", 0L);


    rowData = mReader.get(mEntityId, dataRequest);
    assertFalse(rowData.containsCell("family", "column", 0L));
  }

View Full Code Here

    final KijiDataRequest dataRequest = KijiDataRequest.builder()
        .addColumns(ColumnsDef.create().withMaxVersions(100).add("family", "column"))
        .build();


    // Do a get and verify the value (only one value should be present now).
    KijiRowData rowData = mReader.get(mEntityId, dataRequest);
    String s = rowData.getValue("family", "column", 0L).toString();
    assertEquals(s, "Value at timestamp 0.");


    // Write a second value, with a more-recent timestamp.
    mWriter.put(mEntityId, "family", "column", 1L, "Value at timestamp 1.");


    // Do a get and verify that both values are present.
    rowData = mReader.get(mEntityId, dataRequest);
    assertTrue(rowData.containsCell("family", "column", 0L));
    assertTrue(rowData.containsCell("family", "column", 1L));


    // The most-recent value should be the one with the highest timestamp!
    assertEquals(
        "Value at timestamp 1.", rowData.getMostRecentValue("family", "column").toString());
  }

View Full Code Here

    final KijiDataRequest dataRequest = KijiDataRequest.builder()
        .addColumns(ColumnsDef.create().withMaxVersions(100).add("family", "column"))
        .build();


    // Try this as a get.
    KijiRowData rowData = mReader.get(mEntityId, dataRequest);
    assertNotNull(rowData.getMostRecentValue("family", "column"));
    assertEquals(
      rowData.getMostRecentValue("family", "column").toString(),
      "First value");


    mWriter.put(mEntityId, "family", "column", "Second value");
    rowData = mReader.get(mEntityId, dataRequest);


    assertNotNull(rowData.getMostRecentValue("family", "column"));
    assertEquals(
        rowData.getMostRecentValue("family", "column").toString(),
        "Second value");
  }

View Full Code Here

    final KijiDataRequest dataRequest = KijiDataRequest.builder()
        .addColumns(ColumnsDef.create().withMaxVersions(100).add("family", "column"))
        .build();


    // Try this as a get.
    KijiRowData rowData = mReader.get(mEntityId, dataRequest);
    String s = rowData.getValue("family", "column", 0L).toString();
    assertEquals(s, "Value at timestamp 0.");


    // Delete the entire column.
    mWriter.deleteColumn(mEntityId, "family", "column");


    rowData = mReader.get(mEntityId, dataRequest);


    // Should not get any data back!
    assertFalse(rowData.containsColumn("family", "column"));
  }

View Full Code Here

  public void testReadMissingValue() throws Exception {
    final KijiDataRequest dataRequest = KijiDataRequest.builder()
        .addColumns(ColumnsDef.create().withMaxVersions(100).add("family", "column"))
        .build();


    KijiRowData rowData = mReader.get(mEntityId, dataRequest);
    assertNull(rowData.getValue("family", "column", 0L));
  }

View Full Code Here

    final KijiDataRequest dataRequest = KijiDataRequest.builder()
        .addColumns(ColumnsDef.create().withMaxVersions(100).add("family", "column"))
        .build();


    // Try this as a get.
    KijiRowData rowData = mReader.get(mEntityId, dataRequest);
    String s = rowData.getValue("family", "column", 0L).toString();
    assertEquals(s, "Value at timestamp 0.");


    // Delete the entire family.
    mWriter.deleteFamily(mEntityId, "family");


    rowData = mReader.get(mEntityId, dataRequest);


    // Should not get any data back!
    assertFalse(rowData.containsColumn("family", "column"));
  }

View Full Code Here

    final KijiDataRequest dataRequest = KijiDataRequest.builder()
        .addColumns(ColumnsDef.create().withMaxVersions(100).add("family", "column"))
        .build();


    // Try this as a get.
    KijiRowData rowData = mReader.get(mEntityId, dataRequest);
    String s = rowData.getValue("family", "column", 0L).toString();
    assertEquals(s, "Value at timestamp 0.");


    // Delete the entire row.
    mWriter.deleteRow(mEntityId);


    rowData = mReader.get(mEntityId, dataRequest);


    // Should not get any data back!
    assertFalse(rowData.containsColumn("family", "column"));
  }

View Full Code Here

    List<KijiRowData> dataList = mReader.bulkGet(entityIds, request);


    assertEquals(numRows, dataList.size());


    for (int rowNum = 0; rowNum < numRows; rowNum++) {
      KijiRowData data = dataList.get(rowNum);
      EntityId eid = mTable.getEntityId("row#" + rowNum);
      assertEquals(eid, data.getEntityId());
      assertEquals(
          "This is row " + rowNum + ".",
          data.getMostRecentValue("family", "column").toString()
      );
    }
  }

View Full Code Here

    //mWriter.put(mEntityId, "family", "column", "latest");


    final KijiDataRequest dataRequest = KijiDataRequest.create("family", "column");


    // Sanity check that the write succeeded.
    KijiRowData rowData = mReader.get(mEntityId, dataRequest);
    KijiCell cell = rowData.getMostRecentCell("family", "column");
    assertNotNull(cell);
    assertEquals(cell.getData().toString(), "latest");


    // Let's just check that the timestamp is within 5 minutes of the system time.
    Long storedTimestamp = cell.getTimestamp();

View Full Code Here

      KijiTableReader tableReader = table.openTableReader();
      // Surround with a try/finally so the tablereader gets closed.
      try {
        // Build a DataRequest for the row we want.
        KijiDataRequest dataRequest = KijiDataRequest.create("info", "name");
        KijiRowData result = tableReader.get(entityId, dataRequest);
        String name = result.getMostRecentValue("info", "name").toString();
        System.out.println("Read username " + name + " from table.");
      } finally {
        tableReader.close();
      }
    } finally {

View Full Code Here

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Examples of org.kiji.schema.KijiRowData

Checking for existence of cells

Dealing with large rows

Related Classes of org.kiji.schema.KijiRowData