zookeeper事物操作,其实只是其multi操作的简单封装:
public List<OpResult> multi(Iterable<Op> ops)
基本操作:new Transaction(zk).create(...).setData(...)... .commit();
因为每次返回 this 可以串行操作,最后执行commit(),提交批量事务操作,并返回List<OpResult>结果。
package org.apache.zookeeper;
import org.apache.zookeeper.data.ACL;
import java.util.ArrayList;
import java.util.List;
/**
* Provides a builder style interface for doing multiple updates. This is
* really just a thin layer on top of Zookeeper.multi().
*
* @since 3.4.0
*
*/
public class Transaction {
private ZooKeeper zk;
private List<Op> ops = new ArrayList<Op>();
protected Transaction(ZooKeeper zk) {
this.zk = zk;
}
public Transaction create(final String path, byte data[], List<ACL> acl,
CreateMode createMode) {
ops.add(Op.create(path, data, acl, createMode.toFlag()));
return this;
}
public Transaction delete(final String path, int version) {
ops.add(Op.delete(path, version));
return this;
}
public Transaction check(String path, int version) {
ops.add(Op.check(path, version));
return this;
}
public Transaction setData(final String path, byte data[], int version) {
ops.add(Op.setData(path, data, version));
return this;
}
public List<OpResult> commit() throws InterruptedException, KeeperException {
return zk.multi(ops);
}
}