Package 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
    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 Details

    • 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