设计一个适配器/映射器,将SQL查询转换为Hazelcast谓词和/或SQL查询。可以使用Hazelcast的Query API和Predicate API来实现此适配器/映射器。
代码示例:
public class HazelcastSQLAdapter implements SQLAdapter {
private HazelcastInstance instance;
public HazelcastSQLAdapter(HazelcastInstance instance) {
this.instance = instance;
}
@Override
public ResultSet executeQuery(String sql) throws SQLException {
// convert SQL query to Hazelcast predicate
Predicate predicate = convertToPredicate(sql);
// execute query and return result set
IMap myMap = instance.getMap("myMap");
Collection
}
使用该适配器时,可以像使用任何其他JDBC驱动程序一样执行SQL查询,从而将其转换为Hazelcast谓词,并在分布式缓存中执行查询。以下是示例代码:
HazelcastInstance instance = Hazelcast.newHazelcastInstance(); SQLAdapter adapter = new HazelcastSQLAdapter(instance); Connection connection = DriverManager.getConnection("jdbc:hazelcast:", "", ""); Statement statement = connection.createStatement(); ResultSet resultSet = statement.executeQuery("SELECT * FROM myMap WHERE age > 30");
// process result set while (resultSet.next()) { String key = resultSet.getString("key"); Object value = resultSet.getObject("value"); System.out.println(key + " = " + value); }