io.etcd.jetcd

Interface Txn

All Known Implementing Classes:

TxnImpl

public interface Txn

Txn is the interface that wraps mini-transactions.

Usage examples

 
 txn.If(
    new Cmp(KEY, Cmp.Op.GREATER, CmpTarget.value(VALUE)),
    new Cmp(KEY, cmp.Op.EQUAL, CmpTarget.version(2))
 ).Then(
    Op.put(KEY2, VALUE2, PutOption.DEFAULT),
    Op.put(KEY3, VALUE3, PutOption.DEFAULT)
 ).Else(
    Op.put(KEY4, VALUE4, PutOption.DEFAULT),
    Op.put(KEY4, VALUE4, PutOption.DEFAULT)
 ).commit();
 
 

Txn also supports If, Then, and Else chaining. e.g.

 
 txn.If(
    new Cmp(KEY, Cmp.Op.GREATER, CmpTarget.value(VALUE))
 ).If(
    new Cmp(KEY, cmp.Op.EQUAL, CmpTarget.version(VERSION))
 ).Then(
    Op.put(KEY2, VALUE2, PutOption.DEFAULT)
 ).Then(
    Op.put(KEY3, VALUE3, PutOption.DEFAULT)
 ).Else(
    Op.put(KEY4, VALUE4, PutOption.DEFAULT)
 ).Else(
    Op.put(KEY4, VALUE4, PutOption.DEFAULT)
 ).commit();
 
 

Method Summary

Modifier and Type	Method and Description
CompletableFuture<TxnResponse>	commit() tries to commit the transaction.
Txn	Else(Op... ops) takes a list of operations.
Txn	If(Cmp... cmps) takes a list of comparison.
Txn	Then(Op... ops) takes a list of operations.

Method Detail

If

Txn If(Cmp... cmps)

takes a list of comparison. If all comparisons passed in succeed, the operations passed into Then() will be executed. Or the operations passed into Else() will be executed.

Parameters:

cmps - the comparisons

Returns:

this object

Then

Txn Then(Op... ops)

takes a list of operations. The Ops list will be executed, if the comparisons passed in If() succeed.

Parameters:

ops - the operations

Returns:

this object

Else

Txn Else(Op... ops)

takes a list of operations. The Ops list will be executed, if the comparisons passed in If() fail.

Parameters:

ops - the operations

Returns:

this object

commit

CompletableFuture<TxnResponse> commit()

tries to commit the transaction.

Returns:

a TxnResponse wrapped in CompletableFuture