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How to pass string array in voldemort

开发者 https://www.devze.com 2023-01-26 16:13 出处:网络
I am using Voldemort to store my data. My key is a word and values are number of occurrence of the word and the URL. For example:

I am using Voldemort to store my data. My key is a word and values are number of occurrence of the word and the URL. For example:

key :question
value: 10, www.stackoverflow.com

I am using string[] to pass the values. But while I was trying to use client.put ("xxxx", valuePair);, I am getting java.lang.ClassCastException: [Ljava.lang.String; cannot be cast to java.lang.String. My code looks like this

public class ClientExample { 
  public static void main (String [] args) { 
    String bootstrapUrl = "tcp://localhost:6666";

    ClientConfig cc 开发者_Python百科= new ClientConfig (); 
    cc.setBootstrapUrls (bootstrapUrl); 
    String[] valuePair = new String[2];
    int val = 1;
    String value = new Integer(val).toString();
    valuePair[0]=value;
    valuePair[1] = "www.cnn.com";
    System.out.println("Executed one");
    StoreClientFactory factory = new SocketStoreClientFactory (cc); 
    StoreClient <String, String[]> client = factory.getStoreClient ("test"); 
    System.out.println("Executed two");

    client.put ("xxxx", valuePair); 
    System.out.println("Executed three");
    String[] ans = client.getValue("key");
    System.out.println("Executed four");
    System.out.println ("value " +ans[0] +ans[1]); 
    System.out.println("Executed 5");
  } 
} 


You should edit your store.xml to change the setup of value serializer. It should look something like this right now:

<stores>
  <store>
    <name>test</name>
    <persistence>bdb</persistence>
    <routing>client</routing>
    <replication-factor>1</replication-factor>
    <required-reads>1</required-reads>
    <required-writes>1</required-writes>
    <key-serializer>
      <type>string</type>
    </key-serializer>
    <value-serializer>
      <type>string</type>
    </value-serializer>
  </store>
</stores>

Now, what you need to is to change the value-serializer to:

<value-serializer>
      <type>json</type>
      <schema-info>["string"]</schema-info>
</value-serializer>

Note, that this wouldn't map to Java array, but to Java list. If that is what you really wan't to to this is as close to it as I know of.

However, you might want something like this:

<value-serializer>
      <type>json</type>
      <schema-info>{"occurences":"int32", "site":"string"}</schema-info>
</value-serializer>

Then, you could (snippet):

Map<String, Object> pair = new HashMap<String,Object>();
pair.put("occurences", 10);
pair.put("site", "www.stackoverflow.com");

client.put("question",pair);

System.out.println(client.get("question"));

Hope this was helpful! You can see some documentation of this at:

http://project-voldemort.com/design.php

JSON Serialization Type Details

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