如何从命名空间获取所有键?

How do I get all the keys from a namespace?

如何从 aerospike 命名空间获取所有键,就像我可以使用 map.keyset 从地图中获取键一样。我经历了这个 link Aerospike: how do I get record key?。我做了答案中所说的。我用 writePolicy.sendKey = true 编写了代码,但是当我在 scanCallback 函数中显示密钥时,我仍然得到 NULL

这是我编写记录的代码(任何帮助将不胜感激)

def writeToAerospike(): Boolean = {

val host:Host = new Host("xx.xxx.xxx.xx", 3000)
val client = new AerospikeClient(new ClientPolicy,host)

val policy = new WritePolicy();
policy.sendKey = true;
policy.timeout = 50000;

if(client.isConnected()){
   println("connection to aerospike client sucessful")
   client.put(policy,new Key("test", "testSet", "1"),new Bin("name", "john"))

   //verify if the record is entered correctly
   println(client.get(policy,new Key("test", "testing", "1")).getValue("name"))

   client.close()
   return true
}
return false 
}

我正在使用此示例中的代码来扫描记录:http://www.aerospike.com/docs/client/java/usage/scan/scan.html

class ScanParallelTest extends ScanCallback {

  private var recordCount: Int = _

  def runTest() {
    val client = new AerospikeClient("xxx.xx.xxx.xx", 3000)
    try {
      val policy = new ScanPolicy()
      policy.concurrentNodes = true
      policy.priority = Priority.LOW
      policy.includeBinData = true
      client.scanAll(policy, "test", "testSet", this)
      println("Records " + recordCount)
    } finally {
      client.close()
   }
 }

 def scanCallback(key: Key, record: Record) {
   recordCount += 1

   println("Records " + recordCount )
   println ("key=" + " "+key.userKey.toString() +" and "+" record: "+" "+ record.bins)
  }
}

这是我收到的错误:

com.aerospike.client.AerospikeException: java.lang.NullPointerException
    at com.aerospike.client.command.ScanExecutor.scanParallel(ScanExecutor.java:66)
    at com.aerospike.client.AerospikeClient.scanAll(AerospikeClient.java:551)
    at aerospike.asd.ScanParallelTest.runTest(ScanParallelTest.scala:23)
    at aerospike.asd.test$.main(test.scala:10)
    at aerospike.asd.test.main(test.scala)

Caused by: java.lang.NullPointerException
    at aerospike.asd.ScanParallelTest.scanCallback(ScanParallelTest.scala:35)
    at com.aerospike.client.command.ScanCommand.parseRecordResults(ScanCommand.java:122)
    at com.aerospike.client.command.MultiCommand.parseResult(MultiCommand.java:58)
    at com.aerospike.client.command.SyncCommand.execute(SyncCommand.java:56)
    at com.aerospike.client.command.ScanExecutor$ScanThread.run(ScanExecutor.java:134)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

我尝试将 client.readPolicyDefault.sendKey = true;client.scanPolicyDefault.sendKey = true;client.writePolicyDefault.sendKey = true; 一起使用,代码开始 return 原始键而不是 NULL。

这是 helipilot50 对工作代码的 link:https://github.com/helipilot50/store-primary-key

这对我来说真的很有帮助。谢谢!

添加到 Fahad 的回答:

请记住,存储密钥(而不仅仅是摘要)占用 space。如果您的密钥是一个 100 个字符的字符串,而您的记录是两个 8 字节整数,则密钥存储将使用比这两个值更多的space。

利用这些知识行善而非作恶 :)