“Key-Value Coding” for Java

问题

In Objective-C on Apple there is something called "Key-Value Coding" that allows you to traverse the object graph using strings similar to filesystem paths. There's an informal protocol (i.e. interface) that allows objects to return values based on the "key" they're asked for. e.g. The default is to return the value of a field named by the key, while relational collections like NSDictionaries can implement more interesting behavior.

Pseudo code example:

foo.bar = new baz();
foo.bar.mymap = new map();
foo.bar.mymap['bom'] = 2;

foo.valueForKeyPath("bar.mymap.bom") # 2

Is there anything like this for Java? It would be easy enough to implement, but I thought I'd look first.

回答1:

PropertyUtils.getProperty, from apache's beanutils library, does this for JavaBean properties.

回答2:

Hmm, well, in case anyone else has this question, it looks like MVEL is a good bet:

http://mvel.codehaus.org/Property+Navigation

回答3:

The Ujorm is an open source Java library providing objects based on the key‑value architecture, see the examples.

来源：https://stackoverflow.com/questions/1604141/key-value-coding-for-java