Mocking a ResultSet

ResultSetMocking.java

	static ResultSet mockResultSet(List<String> columns, Object... values) {

		Assert.isTrue( //
				values.length % columns.size() == 0, //
				String //
						.format( //
								"Number of values [%d] must be a multiple of the number of columns [%d]", //
								values.length, //
								columns.size() //
				) //
		);

		List<Map<String, Object>> result = convertValues(columns, values);

		return mock(ResultSet.class, new ResultSetAnswer(result));
	}

	private static List<Map<String, Object>> convertValues(List<String> columns, Object[] values) {

		List<Map<String, Object>> result = new ArrayList<>();

		int index = 0;
		while (index < values.length) {

			Map<String, Object> row = new HashMap<>();
			result.add(row);
			for (String column : columns) {

				row.put(column, values[index]);
				index++;
			}
		}
		return result;
	}

	private static class ResultSetAnswer implements Answer {

		private final List<Map<String, Object>> values;
		private int index = -1;

		public ResultSetAnswer(List<Map<String, Object>> values) {

			this.values = values;
		}

		@Override
		public Object answer(InvocationOnMock invocation) throws Throwable {

			if (invocation.getMethod().getName().equals("next"))
				return next();

			if (invocation.getMethod().getName().equals("getObject"))
				return getObject(invocation.getArgument(0));
			throw new OperationNotSupportedException();
		}

		private Object getObject(String column) {

			return values.get(index).get(column);
		}

		private boolean next() {

			index++;
			return index < values.size();
		}
	}