CompositeValue (Hazelcast Root 3.12.13 API)

java.lang.Object
- com.hazelcast.query.impl.CompositeValue

All Implemented Interfaces:

DataSerializable, IdentifiedDataSerializable, Comparable<CompositeValue>
```
public final class CompositeValue
extends Object
implements Comparable<CompositeValue>, IdentifiedDataSerializable
```
Represents a composite value composed out of a value tuple called components.
Composite values are IdentifiedDataSerializable to facilitate the storage of composite values in composite indexes, but they are never transferred over the wire.
Composite values are Comparable and ordered according to a lexicographical order defined by the ordering of their individual components. There are 3 special values defined for components:
1. NEGATIVE_INFINITY which represents a value that is equal to itself and less than any other value. Negative infinities are never stored in indexes and used only for querying.
2. AbstractIndex.NULL which represents a null-like value that is equal to itself and less than any other value except NEGATIVE_INFINITY. Null values may be stored in indexes.
3. POSITIVE_INFINITY which represents a value that is equal to itself and greater than any other value. Positive infinities are never stored in indexes and used only for querying.
Basically, these special values allow to define two isolated regions in the index key space: (-inf, null] and (null, +inf). The first one is used for the null equality queries and the second one is used for the regular equality and range queries. This separation is needed to ensure that null values are excluded from the regular range queries like "a < 0".
A typical ordered index key space layout for the attributes a, b and c looks like this:
```
    a     b     c
 null  null  null
 null  null   1.0
    1   'b'   0.0
    1   'b'   0.5
    2   'a'   null
 
```
Notice that the ordering of the keys is suitable for the purpose of querying only if keys share some common prefix. In the most general case, any query to an ordered index may be reduced to a range query:
```
 a = null and b = null and c = null
 [null, null, null] <= [a, b, c] <= [null, null, null]

 a = 2
 [2, -inf, -inf] < [a, b, c] < [2, +inf, +inf]

 a = 1 and b = 'b' and c > 0.0
 [1, 'b', 0.0] < [a, b, c] < [1, 'b', +inf]

 a < 2
 [null, -inf, -inf] < [a, b, c] < [2, -inf, -inf]

 a = 1 and b >= 'a' and b < 'z'
 [1, 'a', -inf] < [a, b, c] < [1, 'z', -inf]
 
```
The later two examples may look counterintuitive at first, but consider what is the first key that is greater than any other key having [1, 'a'] as a prefix? It's [1, 'a', -inf]. The same applies to [1, 'z', -inf], it's the first key that is less than any other key having [1, 'z'] prefix.
For unordered indexes, there is no order defined for index keys. The only comparison operation supported is the full equality of keys expressed as composite values. Partial key matching is impossible.

Field Summary

Fields
Modifier and Type	Field and Description
`static ComparableIdentifiedDataSerializable`	`NEGATIVE_INFINITY` Represents a value that is equal to itself and less than any other value.
`static ComparableIdentifiedDataSerializable`	`POSITIVE_INFINITY` Represents a value that is equal to itself and greater than any other value.

Constructor Summary

Constructors
Constructor and Description
`CompositeValue()` Constructs a new composite value for the deserialization purposes.
`CompositeValue(Comparable[] components)` Constructs a new composite value from the given components.
`CompositeValue(int width, Comparable prefix, Comparable filler)` Constructs a new composite value of the given width having the given prefix value as its first component and the filler value as its remaining components.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`compareTo(CompositeValue that)`
`boolean`	`equals(Object o)`
`Comparable[]`	`getComponents()` Returns the components of this composite value.
`int`	`getFactoryId()` Returns DataSerializableFactory factory ID for this class.
`int`	`getId()` Returns type identifier for this class.
`int`	`hashCode()`
`void`	`readData(ObjectDataInput in)` Reads fields from the input stream
`String`	`toString()`
`void`	`writeData(ObjectDataOutput out)` Writes object fields to output stream

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - NEGATIVE_INFINITY
```
public static final ComparableIdentifiedDataSerializable NEGATIVE_INFINITY
```
    Represents a value that is equal to itself and less than any other value.
  - POSITIVE_INFINITY
```
public static final ComparableIdentifiedDataSerializable POSITIVE_INFINITY
```
    Represents a value that is equal to itself and greater than any other value.
- Constructor Detail
  - CompositeValue
```
public CompositeValue()
```
    Constructs a new composite value for the deserialization purposes.
  - CompositeValue
```
public CompositeValue(Comparable[] components)
```
    Constructs a new composite value from the given components.
    For performance reasons, the ownership of the passed components array is transferred to the newly constructed composite value.
  - CompositeValue
```
public CompositeValue(int width,
                      Comparable prefix,
                      Comparable filler)
```
    Constructs a new composite value of the given width having the given prefix value as its first component and the filler value as its remaining components.
- Method Detail
  - getComponents
```
public Comparable[] getComponents()
```
    Returns the components of this composite value.
    For performance reasons, the internal components array is directly exposed to the caller.
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - compareTo
```
public int compareTo(CompositeValue that)
```
    Specified by:
    
    compareTo in interface Comparable<CompositeValue>
  - getFactoryId
```
public int getFactoryId()
```
    Description copied from interface: IdentifiedDataSerializable
    
    Returns DataSerializableFactory factory ID for this class.
    
    Specified by:
    
    getFactoryId in interface IdentifiedDataSerializable
    
    Returns:
    
    factory ID
  - getId
```
public int getId()
```
    Description copied from interface: IdentifiedDataSerializable
    
    Returns type identifier for this class. It should be unique per DataSerializableFactory.
    
    Specified by:
    
    getId in interface IdentifiedDataSerializable
    
    Returns:
    
    type ID
  - writeData
```
public void writeData(ObjectDataOutput out)
               throws IOException
```
    Description copied from interface: DataSerializable
    
    Writes object fields to output stream
    
    Specified by:
    
    writeData in interface DataSerializable
    
    Parameters:
    
    out - output
    
    Throws:
    
    IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed.
  - readData
```
public void readData(ObjectDataInput in)
              throws IOException
```
    Description copied from interface: DataSerializable
    
    Reads fields from the input stream
    
    Specified by:
    
    readData in interface DataSerializable
    
    Parameters:
    
    in - input
    
    Throws:
    
    IOException - if an I/O error occurs. In particular, an IOException may be thrown if the input stream has been closed.

Class CompositeValue

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

NEGATIVE_INFINITY

POSITIVE_INFINITY

Constructor Detail

CompositeValue

CompositeValue

CompositeValue

Method Detail

getComponents

hashCode

equals

toString

compareTo

getFactoryId

getId

writeData

readData