Apex Reference Guide

Apex Reference Guide
Release Notes
Apex DML Operations
ApexPages Namespace
AppLauncher Namespace
Approval Namespace
Auth Namespace
Cache Namespace
CacheBuilder Interface
Org Class
OrgPartition Class
Partition Class
Session Class
Session Constants
Session Methods
SessionPartition Class
Cache Exceptions
Visibility Enum
Canvas Namespace
ChatterAnswers Namespace
CommerceExtension Namespace
CommerceOrders Namespace
CommercePayments Namespace
CommerceTax Namespace
Compression Namespace (Developer Preview)
ConnectApi Namespace
Context Namespace
Database Namespace
Datacloud Namespace
DataRetrieval Namespace
DataSource Namespace
DataWeave Namespace
Dom Namespace
EventBus Namespace
ExternalService Namespace
Flow Namespace
FormulaEval Namespace (Beta)
fsccashflow Namespace
Functions Namespace
industriesNlpSvc
IndustriesDigitalLending Namespace
Invocable Namespace
IsvPartners Namespace
KbManagement Namespace
LxScheduler Namespace
Messaging Namespace
Metadata Namespace
PlaceQuote Namespace
Pref_center Namespace
Process Namespace
QuickAction Namespace
Reports Namespace
RichMessaging Namespace
Schema Namespace
Search Namespace
Sfc Namespace
Sfdc_Checkout Namespace
Sfdc_Enablement Namespace
sfdc_surveys Namespace
Site Namespace
Slack Namespace
Support Namespace
System Namespace
TerritoryMgmt Namespace
TxnSecurity Namespace
UserProvisioning Namespace
VisualEditor Namespace
Wave Namespace
Appendices
PDF

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Session Class

Use the Cache.Session class to add, retrieve, and manage values in the session cache. The session cache is active as long as the user’s Salesforce session is valid (the user is logged in, and the session is not expired).

Namespace

Cache

Usage

Cache Key Format

This table lists the format of the key parameter that some methods in this class take, such as put, get, and contains.

Key Format Description
namespace.partition.key Fully qualified key name.
key Refers to a partition marked as default when the namespace.partition prefix is omitted.
local.partition.key Use the local prefix to refer to the org’s namespace when the org doesn’t have a namespace defined. If the org has a namespace defined, the local prefix also refers to that org’s namespace.
  • If no default partition is specified in the org, calling a cache method without fully qualifying the key name causes a ​Cache.Session.SessionCacheException to be thrown.
  • The local prefix in an installed managed package refers to the namespace of the subscriber org and not the package’s namespace. The cache put calls are not allowed in a partition that the invoking class doesn’t own.

Note

Example

This class is the controller for a sample Visualforce page (shown in the subsequent code sample). The cached values are initially added to the cache by the init() method, which the Visualforce page invokes when it loads through the action attribute. The cache keys don’t contain the namespace.partition prefix. They all refer to a default partition in your org. The Visualforce page expects a partition named myPartition. To run this sample, create a default partition in your org with the name myPartition.

The Visualforce page contains four output components. The first three components call get methods on the controller that return the following values from the cache: a date, data based on the MyData inner class, and a counter. The next output component uses the $Cache.Session global variable to get the cached string value for the key named output. Next, the $Cache.Session global variable is used again in the Visualforce page to iterate over the elements of a cached value of type List. The size of the list is also returned.

The Visualforce page also contains two buttons. The Rerender button invokes the go() method on the controller. This method increases the values of the counter and the custom data in the cache. If you click Rerender, the two counters increase by one each time. The go() method retrieves the values of these counters from the cache, increments their values by one, and stores them again in the cache.

The Remove button deletes the date-time value (with key datetime) from the cache. As a result, the value next to Cached datetime: is cleared on the page.

This is the Visualforce page that corresponds to the SessionCacheController class.

This is the output of the page after clicking the Rerender button twice. The counter value could differ in your case if a key named counter was already in the cache before running this sample.

Session Constants

The Session class provides a constant that you can use when setting the time-to-live (TTL) value.
Constant Description
MAX_TTL_SECS Represents the maximum amount of time, in seconds, to keep the cached value in the session cache.

Session Methods

The following are methods for Session. All methods are static.

contains(key)

Returns true if the session cache contains a cached value corresponding to the specified key.

Signature

public static Boolean contains(String key)

Parameters

key
Type: String
A case-sensitive string value that uniquely identifies a cached value. For information about the format of the key name, see Usage.

Return Value

Type: Boolean

true if a cache entry is found. Othewise, false.

contains(setOfKeys)

Returns true if the cache contains values for a specified set of keys.

Signature

public static Map <String, Boolean> contains (Set<String> keys)

Parameters

setOfKeys
Type: Set <String>

A set of keys that uniquely identifies cached values. For information about the format of the key name, see Usage.

Return Value

Type: Map <String, Boolean>

Returns the cache key and corresponding Boolean value indicating that the key entry exists. The Boolean value is false if the key entry doesn't exist.

Usage

The number of input keys cannot exceed the maximum limit of 10.

Example

In this example, the code checks for the presence of multiple keys on the default partition. It fetches the cache key and the corresponding Boolean value for the key entry from the session cache of the default partition.

In this example, the code checks for the presence of multiple keys on different partitions. It fetches the cache key and the corresponding Boolean value for the key entry from the session cache of different partitions.

get(key)

Returns the cached value corresponding to the specified key from the session cache.

Signature

public static Object get(String key)

Parameters

key
Type: String
A case-sensitive string value that uniquely identifies a cached value. For information about the format of the key name, see Usage.

Return Value

Type: Object

The cached value as a generic object type. Cast the returned value to the appropriate type.

Usage

Because Cache.Session.get() returns an object, we recommend that you cast the returned value to a specific type to facilitate use of the returned value.

If a Cache.Session.get() call doesn’t find the referenced key, it returns null.

get(keys)

Returns the cached values corresponding to the specified set of keys from the session cache.

Signature

public static Map <String, Object> get (Set <String> keys)

Parameters

keys
Type: Set <String>

A set of keys that uniquely identify cached values. For information about the format of the key name, see Usage.

Return Value

Type: Map <String, Object>

Returns the cache key and corresponding value. Returns null when no corresponding value is found for an input key.

Usage

The number of input keys cannot exceed the maximum limit of 10.

Example

Fetch multiple keys from the session cache of the default partition.

Fetch multiple keys from the session cache of different partitions.

get(cacheBuilder, key)

Returns the cached value corresponding to the specified key from the session cache. Use this method if your cached value is a class that implements the CacheBuilder interface.

Signature

public static Object get(System.Type cacheBuilder, String key)

Parameters

cacheBuilder
Type: System.Type
The Apex class that implements the CacheBuilder interface.
key
Type: String
A case-sensitive string value that, combined with the class name corresponding to the cacheBuilder parameter, uniquely identifies a cached value.

Return Value

Type: Object

The cached value as a generic object type. Cast the returned value to the appropriate type.

Usage

Because Cache.Session.get(cacheBuilder, key) returns an object, cast the returned value to a specific type to facilitate use of the returned value.

getAvgGetSize()

Returns the average item size of all the keys fetched from the session cache, in bytes.

Signature

public static Long getAvgGetSize()

Return Value

Type: Long

getAvgGetTime()

Returns the average time taken to get a key from the session cache, in nanoseconds.

Signature

public static Long getAvgGetTime()

Return Value

Type: Long

getAvgValueSize()

Deprecated and available only in API versions 49.0 and earlier. Returns the average item size for keys in the session cache, in bytes.

Signature

public static Long getAvgValueSize()

Return Value

Type: Long

getCapacity()

Returns the percentage of session cache capacity that has been used.

Signature

public static Double getCapacity()

Return Value

Type: Double

Used cache as a percentage number.

getKeys()

Returns all keys that are stored in the session cache and visible to the invoking namespace.

Signature

public static Set<String> getKeys()

Return Value

Type: Set<String>

A set containing all cache keys.

getMaxGetSize()

Returns the maximum item size of all the keys fetched from the session cache, in bytes.

Signature

public static Long getMaxGetSize()

Return Value

Type: Long

getMaxGetTime()

Returns the maximum time taken to get a key from the session cache, in nanoseconds.

Signature

public static Long getMaxGetTime()

Return Value

Type: Long

getMaxValueSize()

Deprecated and available only in API versions 49.0 and earlier. Returns the maximum item size for keys in the session cache, in bytes.

Signature

public static Long getMaxValueSize()

Return Value

Type: Long

getMissRate()

Returns the miss rate in the session cache.

Signature

public static Double getMissRate()

Return Value

Type: Double

getName()

Returns the name of the default cache partition.

Signature

public String getName()

Return Value

Type: String

The name of the default cache partition.

getNumKeys()

Returns the total number of keys in the session cache.

Signature

public static Long getNumKeys()

Return Value

Type: Long

getPartition(partitionName)

Returns a partition from the session cache that corresponds to the specified partition name.

Signature

public static cache.SessionPartition getPartition(String partitionName)

Parameters

partitionName
Type: String
A partition name that is qualified by the namespace, for example, namespace.partition.

Return Value

Type: Cache.SessionPartition

Example

After you get the session partition, you can add and retrieve the partition’s cache values.

isAvailable()

Returns true if the session cache is available for use. The session cache isn’t available when an active session isn’t present, such as in asynchronous Apex or code called by asynchronous Apex. For example, if batch Apex causes an Apex trigger to execute, the session cache isn’t available in the trigger because the trigger runs in asynchronous context.

Signature

public static Boolean isAvailable()

Return Value

Type: Boolean

true if the session cache is available. Otherwise, false.

put(key, value)

Stores the specified key/value pair as a cached entry in the session cache. The put method can write only to the cache in your org’s namespace.

Signature

public static void put(String key, Object value)

Parameters

key
Type: String
A string that uniquely identifies the value to be cached. For information about the format of the key name, see Usage.
value
Type: Object
The value to store in the cache. The cached value must be serializable.

Return Value

Type: void

put(key, value, visibility)

Stores the specified key/value pair as a cached entry in the session cache and sets the cached value’s visibility.

Signature

public static void put(String key, Object value, Cache.Visibility visibility)

Parameters

key
Type: String
A string that uniquely identifies the value to be cached. For information about the format of the key name, see Usage.
value
Type: Object
The value to store in the cache. The cached value must be serializable.
visibility
Type: Cache.Visibility
Indicates whether the cached value is available only to Apex code that is executing in the same namespace or to Apex code executing from any namespace.

Return Value

Type: void

put(key, value, ttlSecs)

Stores the specified key/value pair as a cached entry in the session cache and sets the cached value’s lifetime.

Signature

public static void put(String key, Object value, Integer ttlSecs)

Parameters

key
Type: String
A string that uniquely identifies the value to be cached. For information about the format of the key name, see Usage.
value
Type: Object
The value to store in the cache. The cached value must be serializable.
ttlSecs
Type: Integer
The amount of time, in seconds, to keep the cached value in the session cache. The cached values remain in the cache as long as the Salesforce session hasn’t expired. The maximum value is 28,800 seconds or eight hours. The minimum value is 300 seconds or five minutes.

Return Value

Type: void

put(key, value, ttlSecs, visibility, immutable)

Stores the specified key/value pair as a cached entry in the session cache. This method also sets the cached value’s lifetime, visibility, and whether it can be overwritten by another namespace.

Signature

public static void put(String key, Object value, Integer ttlSecs, cache.Visibility visibility, Boolean immutable)

Parameters

key
Type: String
A string that uniquely identifies the value to be cached. For information about the format of the key name, see Usage.
value
Type: Object
The value to store in the cache. The cached value must be serializable.
ttlSecs
Type: Integer
The amount of time, in seconds, to keep the cached value in the session cache. The cached values remain in the cache as long as the Salesforce session hasn’t expired. The maximum value is 28,800 seconds or eight hours. The minimum value is 300 seconds or five minutes.
visibility
Type: Cache.Visibility
Indicates whether the cached value is available only to Apex code that is executing in the same namespace or to Apex code executing from any namespace.
immutable
Type: Boolean
Indicates whether the cached value can be overwritten by another namespace (false) or not (true).

Return Value

Type: void

remove(key)

Deletes the cached value corresponding to the specified key from the session cache.

Signature

public static Boolean remove(String key)

Parameters

key
Type: String
A case-sensitive string value that uniquely identifies a cached value. For information about the format of the key name, see Usage.

Return Value

Type: Boolean

true if the cache value was successfully removed. Otherwise, false.

remove(cacheBuilder, key)

Deletes the cached value corresponding to the specified key from the session cache. Use this method if your cached value is a class that implements the CacheBuilder interface.

Signature

public static Boolean remove(System.Type cacheBuilder, String key)

Parameters

cacheBuilder
Type: System.Type
The Apex class that implements the CacheBuilder interface.
key
Type: String
A case-sensitive string value that, combined with the class name corresponding to the cacheBuilder parameter, uniquely identifies a cached value.

Return Value

Type: Boolean

true if the cache value was successfully removed. Otherwise, false.