Get Compare Exchange Values Operation
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Use
GetCompareExchangeValuesOperation
to return the saved compare-exchange Values for the specified Keys. -
For an overview of the 'Compare Exchange' feature click: Compare Exchange Overview
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In this page:
Syntax
Methods:
GetCompareExchangeValuesOperation(Class<T> clazz, String[] keys);
GetCompareExchangeValuesOperation(Class<T> clazz, String startWith)
GetCompareExchangeValuesOperation(Class<T> clazz, String startWith, Integer start)
GetCompareExchangeValuesOperation(Class<T> clazz, String startWith, Integer start, Integer pageSize)
Parameters | Type | Description |
---|---|---|
keys | String[] | List of keys to get |
startWith | String | A common prefix for those keys whose values should be returned |
start | int | The number of items that should be skipped |
pageSize | int | The maximum number of values that will be retrieved |
Returned object:
public class CompareExchangeValue<T> {
private String key;
private long index;
private T value;
public CompareExchangeValue(String key, long index, T value) {
this.key = key;
this.index = index;
this.value = value;
}
public String getKey() {
return key;
}
public void setKey(String key) {
this.key = key;
}
public long getIndex() {
return index;
}
public void setIndex(long index) {
this.index = index;
}
public T getValue() {
return value;
}
public void setValue(T value) {
this.value = value;
}
}
Return Value | Description |
---|---|
Map<String, CompareExchangeValue<T>> |
A map containing 'Key' to 'CompareExchangeValue' associations |
Example I - Get Values for Specified Keys
Map<String, CompareExchangeValue<String>> compareExchangeValues
= store.operations().send(
new GetCompareExchangeValuesOperation<>(String.class, new String[]{"Key-1", "Key-2"}));
Example II - Get Values for Keys with Common Prefix
// Get values for keys that have the common prefix 'users'
// Retrieve maximum 20 entries
Map<String, CompareExchangeValue<User>> compareExchangeValues
= store.operations().send(
new GetCompareExchangeValuesOperation<>(User.class, "users", 0, 20));