如何使用java从google app engine数据存储中加载值以执行或操作

我必须使用2个条件或条件来加载实体值 例如，

从数据库中选择*，其中（电子邮件=xyz@gmail.com或UUID=1234）

已尝试使用筛选器：

Filter emailFilter =
              new FilterPredicate("email", FilterOperator.EQUAL, email);

Filter firstFilter =
              new FilterPredicate("firstname", FilterOperator.EQUAL, firstName);

Filter filter =
              CompositeFilterOperator.or(emailFilter, firstFilter);

但是我不明白在加载时如何使用这个过滤器

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如何使用数据存储中的筛选器执行此操作？

如果我理解正确，您只需将筛选器应用于查询并检索结果：

// Your filter declarations
Filter emailFilter =
    new FilterPredicate("email", FilterOperator.EQUAL, email);
Filter firstFilter =
    new FilterPredicate("firstname", FilterOperator.EQUAL, firstName);
Filter filter =
    CompositeFilterOperator.or(emailFilter, firstFilter);

// Use class Query to assemble a query
Query q = new Query("Person").setFilter(filter)

// Use PreparedQuery interface to retrieve results
PreparedQuery pq = datastore.prepare(q);

for (Entity result : pq.asIterable()) {
    // result.getProperty("lastname")
}