Question

我有一个简单的POJO：

class Person {
  String name;
  int age;
}

我希望能够在缓存上创建一个索引，然后允许我执行以下伪查询：

find me all the people whose name is EQUAL to John and their age is GREATERTHAN 30

我尝试了MultiExtractor似乎创建了我想要的索引，但是当我使用Filter对象构建查询时，我似乎仍然最终得到了未经优化的查询。

Answer 1

最简单的解决方案是添加属性访问器：

public class Person {
  public Person(String name, int age) {
    this.name = name;
    this.age = age;
  }

  public String getName() {
    return name;
  }

  public int getAge() {
    return age;
  }

  private String name;
  private int age;
}

现在您可以查询：

// find me all the people whose name is EQUAL to
// John and their age is GREATERTHAN 30
Filter filter = new AndFilter(
                    new EqualsFilter("getName", "John"),
                    new GreaterFilter("getAge", Integer.valueOf(30));
Set setKeys = cache.keySet(filter);

您还可以在SQL中对该过滤器进行编码。请参阅：https://community.oracle.com/message/11217211#11217211

其他资源：

为Coherence缓存创建查询和过滤

1 个答案: