@Test public void testAcquireAndMutate() throws Exception { final String row = "testAcquireAndMutate"; final String dataColumn = "data"; final String value = "test"; ColumnPrefixUniquenessConstraint<String> unique = new ColumnPrefixUniquenessConstraint<String>(keyspace, UNIQUE_CF, row) .withConsistencyLevel(ConsistencyLevel.CL_ONE) .withUniqueId("def"); try { unique.acquireAndApplyMutation( new Function<MutationBatch, Boolean>() { @Override public Boolean apply(MutationBatch m) { m.withRow(UNIQUE_CF, row).putColumn(dataColumn, value, null); return true; } }); String column = unique.readUniqueColumn(); Assert.assertNotNull(column); } catch (Exception e) { e.printStackTrace(); LOG.error("", e); Assert.fail(); } finally { } ColumnList<String> columns = keyspace.prepareQuery(UNIQUE_CF).getKey(row).execute().getResult(); Assert.assertEquals(2, columns.size()); Assert.assertEquals(value, columns.getStringValue(dataColumn, null)); unique.release(); columns = keyspace.prepareQuery(UNIQUE_CF).getKey(row).execute().getResult(); Assert.assertEquals(1, columns.size()); Assert.assertEquals(value, columns.getStringValue(dataColumn, null)); }