NullMask (Jackcess 5.0.1 API)

java.lang.Object
- com.healthmarketscience.jackcess.impl.NullMask

```
public class NullMask
extends Object
```
Bitmask that indicates whether or not each column in a row is null. Also holds values of boolean columns.

Author:

Tim McCune

Constructor Summary

Constructors
Constructor Description

NullMask(int columnCount)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`byteSize()`
`boolean`	`isNull(ColumnImpl column)`
`void`	`markNotNull(ColumnImpl column)`	Indicate that the column with the given number is not `null` (or a boolean value is `true`).
`void`	`read(ByteBuffer buffer)`	Read a mask in from a buffer
`void`	`write(ByteBuffer buffer)`	Write a mask to a buffer

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - NullMask
```
public NullMask(int columnCount)
```
    Parameters:
    
    columnCount - Number of columns in the row that this mask will be used for
- Method Detail
  - read
```
public void read(ByteBuffer buffer)
```
    Read a mask in from a buffer
  - write
```
public void write(ByteBuffer buffer)
```
    Write a mask to a buffer
  - isNull
```
public boolean isNull(ColumnImpl column)
```
    Parameters:
    
    column - column to test for null
    
    Returns:
    
    Whether or not the value for that column is null. For boolean columns, returns the actual value of the column (where non-null == true)
  - markNotNull
```
public void markNotNull(ColumnImpl column)
```
    Indicate that the column with the given number is not null (or a boolean value is true).
    
    Parameters:
    
    column - column to be marked non-null
  - byteSize
```
public int byteSize()
```
    Returns:
    
    Size in bytes of this mask