基于接口的匿名类定义......也许？ [英] Anonymous class definition based on interface... maybe?

问题描述

我在 Spring in Action 一书中看到了这个Java片段，但我对语言结构并不熟悉。

I saw this Java snippet in the book Spring in Action, but I'm not familiar with the language construct.

new RowMapper() {
  public Object mapRow() throws SQLException, DataAccessException {
    Motorist motorist = new Motorist();
    motorist.setId(rs.getInt(1));
    motorist.setEmail(rs.getString(2));
    motorist.setPassword(rs.getString(3));
    motorist.setFirstName(rs.getString(4));
    motorist.setLastName(rs.getString(5));
    return motorist;
  }
}

根据 Spring文档，RowMapper是一个界面。它看起来像一个基于RowMapper接口的匿名类定义。 new 关键字有点令人困惑，让我想知道这是否也会创建一个匿名类的实例。我猜是的，因为如果该类没有名称，你将如何在定义它的行之后创建一个实例？

According the Spring documentation, RowMapper is an interface. It looks to me like an anonymous class definition based on the RowMapper interface. The new keyword is a little confusing, making me wonder if this also creates one instance of the anonymous class. I would guess yes, because if the class has no name, how will you ever create an instance after the line that defines it?

可以任何人都确认我的猜测：

Can anyone confirm my guesses that:

• 这是一个基于RowMapper接口的匿名类定义，


• 它创建该类的单个实例？

推荐答案

这是一个基于RowMapper接口的匿名类定义

这正是它的本质。

它会创建该类的单个实例吗？

是的。这是正确的。

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