可过期的对象

单个对象

Suppliers

https://google.github.io/guava/releases/19.0/api/docs/com/google/common/base/Suppliers.html#memoizeWithExpiration(com.google.common.base.Supplier, long, java.util.concurrent.TimeUnit)

example:

http://stackoverflow.com/questions/7864637/what-is-the-best-way-to-cache-single-object-within-fixed-timeout

public class JdkVersionService {

    @Inject
    private JdkVersionWebService jdkVersionWebService;

    // No need to check too often. Once a year will be good :) 
    private final Supplier latestJdkVersionCache
            = Suppliers.memoizeWithExpiration(jdkVersionSupplier(), 365, TimeUnit.DAYS);


    public JdkVersion getLatestJdkVersion() {
        return latestJdkVersionCache.get();
    }

    private Supplier jdkVersionSupplier() {
        return new Supplier() {
            public JdkVersion get() {
                return jdkVersionWebService.checkLatestJdkVersion();
            }
        };
    }
}

多个对象

Class CacheBuilder

https://google.github.io/guava/releases/16.0/api/docs/com/google/common/cache/CacheBuilder.html

example:

   LoadingCache graphs = CacheBuilder.newBuilder()
       .maximumSize(10000)
       .expireAfterWrite(10, TimeUnit.MINUTES)
       .removalListener(MY_LISTENER)
       .build(
           new CacheLoader() {
             public Graph load(Key key) throws AnyException {
               return createExpensiveGraph(key);
             }
           });