zookeeper错误KeeperErrorCode = ConnectionLoss解决

原因:

一般是由于连接还未完成就执行zookeeper的get/create/exsit操作引起的.

解决方法:

利用"CountDownLatch 类 + zookeeper的watcher + zookeeper的getStat" 实现连接完成后再调用.

可防止此错误发生.

示例类如下(为一配置获取类):

[java] view
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1. import java.util.concurrent.CountDownLatch;
2. import org.apache.zookeeper.WatchedEvent;
3. import org.apache.zookeeper.Watcher;
4. import org.apache.zookeeper.Watcher.Event.KeeperState;
5. import org.apache.zookeeper.ZooKeeper;
6. import org.apache.zookeeper.ZooKeeper.States;
7. import org.apache.zookeeper.data.Stat;
8. public class Conf{
9. public static void waitUntilConnected(ZooKeeper zooKeeper, CountDownLatch connectedLatch) {
10. if (States.CONNECTING == zooKeeper.getState()) {
11. try {
12. connectedLatch.await();
13. } catch (InterruptedException e) {
14. throw new IllegalStateException(e);
15. }
16. }
17. }
18. static class ConnectedWatcher implements Watcher {
19. private CountDownLatch connectedLatch;
20. ConnectedWatcher(CountDownLatch connectedLatch) {
21. this.connectedLatch = connectedLatch;
22. }
23. @Override
24. public void process(WatchedEvent event) {
25. if (event.getState() == KeeperState.SyncConnected) {
26. connectedLatch.countDown();
27. }
28. }
29. }
30. static public Conf Instance(){
31. if(static_ == null){
32. static_ = new Conf();
33. }
34. return static_;
35. }
36. public boolean Init(String hostports, int times){
37. try{
38. CountDownLatch connectedLatch = new CountDownLatch(1);
39. Watcher watcher = new ConnectedWatcher(connectedLatch);
40. zk_ = new ZooKeeper(hostports, times, watcher);
41. waitUntilConnected(zk_, connectedLatch);
42. }
43. catch(Exception e){
44. System.out.println(e);
45. return false;
46. }
47. return true;
48. }
49. public String Get(String keys){
50. String re = "";
51. String ppath = "/zookeeper";
52. int oldpos = -1;
53. int pos = 0;
54. while(true){
55. pos = keys.indexOf(".", oldpos + 1);
56. if(pos < 0){
57. ppath += "/";
58. String str = keys.substring(oldpos + 1);
59. ppath += str;
60. break;
61. }
62. ppath += "/";
63. String str = keys.substring(oldpos + 1,  pos);
64. ppath += str;
65. oldpos = pos;
66. }
67. Stat stat = new Stat();
68. try{
69. byte[] b = zk_.getData(ppath, false, stat);    //获取节点的信息及存储的数据
70. re = new String(b);
71. }
72. catch(Exception e){
73. System.out.println(e);
74. }
75. return re;
76. }
77. private Conf(){
78. }
79. private ZooKeeper zk_;
80. static private Conf static_;
81. public static void main(String args[]){
82. String hostports = "192.168.1.88:2181,192.168.1.88:2182,192.168.1.88:2183";
83. Conf.Instance().Init(hostports, 1000);
84. String str = Conf.Instance().Get("conf.logicpoint.subscriberserverip");
85. str = Conf.Instance().Get("conf.logicpoint.subscriberserverport");
86. System.out.println(str);
87. while(true){
88. try{Thread.sleep(100);}
89. catch(Exception e){
90. }
91. }
92. }
93. }