关于垃圾回收
Core   java里有这样一段话

If   a   resource   needs   to   be   closed   as   soon   as   you   have   finished   using   it,   you   need   to   manage   it   manually.   Supply   a   method   such   as   dispose   or   close   that   you   call   to   clean   up   what   needs   cleaning.   Just   as   importantly,   if   a   class   you   use   has   such   a   method,   you   need   to   call   it   when   you   are   done   with   the   object.

什么叫a   resource   needs   to   be   closed   as   soon   as   you   have   finished   using   it,是当你用完这个资源就想马上释放的意思?那这个close()函数该怎么写?
不是很理解,哪位高人能给俺举个例子呢~~

------解决方案--------------------
If a resource needs to be closed as soon as you have finished using it, you need to manage it manually.
当你使用完一个资源，就必须关闭它，而且你必须手工完成这个动作。

举个例子，数据库操作

Connection conn = DriverManager.getConnection(/*数据库驱动*/);
Statement stmt = conn.createStatement();
stmt.execute(/*SQL语句*/);
/*某些其他操作*/
//最后关闭连接，释放资源
stmt.close();
conn.close();

可以看到，这里的Connection对象和Statement对象是手工调用close()关闭的，虽然垃圾回收器会在这些对象的生命周期结束的时候回收这些对象，但并不推荐这么做。因为我们不知道垃圾回收器什么时候启动，什么时候回真正将这些资源释放，所以要手工清理。