Question

我正在尝试从Apache Ignite缓存中获取所有项目。

目前，我可以使用来获得单个物品

ClientCache<Integer, BinaryObject> cache = igniteClient.cache("myCache").withKeepBinary();

BinaryObject temp = cache.get(1);

要获取所有密钥，我已经尝试了以下操作：

 try ( QueryCursor<Entry<Integer,BinaryObject>> cursor = cache.query(new ScanQuery<Integer, BinaryObject>(null))) {
               for (Object p : cursor)
                 System.out.println(p.toString());
             }

这将返回内部的org.apache.ignite.internal.client.thin.ClientCacheEntry列表，而我无法调用getValue。

如何获取此缓存的所有项目？

Answer 1

通过使用迭代器，您可以从缓存中获取所有值和键。下面是从缓存中检索所有值的示例代码。

Iterator<Entry<Integer, BinaryObject>> itr = cache.iterator();                
                  while(itr.hasNext()) {
                     BinaryObject object = itr.next().getValue();
                     System.out.println(object);
                 }

Answer 2

以下内容可以帮助您遍历缓存中的所有记录。

import javax.cache.Cache.Entry;

import org.apache.ignite.Ignite;
import org.apache.ignite.IgniteCache;
import org.apache.ignite.Ignition;
import org.apache.ignite.binary.BinaryObject;

public class App5BinaryObject {

public static void main(String[] args) {
    Ignition.setClientMode(true);

    try (Ignite client = Ignition
            .start("/Users/amritharajherle/git_new/ignite-learning-by-examples/complete/cfg/ignite-config.xml")) {

        IgniteCache<BinaryObject, BinaryObject> cities = client.cache("City").withKeepBinary();
        int count = 0;
        for (Entry<BinaryObject, BinaryObject> entry : cities) {
            count++;
            BinaryObject key = entry.getKey();
            BinaryObject value = entry.getValue();

            System.out.println("CountyCode=" + key.field("COUNTRYCODE") + ", DISTRICT = " + value.field("DISTRICT")
                    + ", POPULATION = " + value.field("POPULATION") + ", NAME = " + value.field("NAME"));
        }
        System.out.println("total cities count = " + count);

    }

  }

}

Apache Ignite-从缓存中获取全部

2 个答案: